LOOMIS SAYLES FUNDS
485BPOS, 1998-11-30
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<PAGE>
 
   AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON NOVEMBER 30, 1998
 
                                         REGISTRATION NOS. 811-6241 AND 33-39133
 
================================================================================
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
 
                               ----------------
 
                                   FORM N-1A
                             REGISTRATION STATEMENT
                                    UNDER 
                          THE SECURITIES ACT OF 1933
                                                                   [X]
 
                         PRE-EFFECTIVE AMENDMENT NO.               [_]
 
                        POST-EFFECTIVE AMENDMENT NO. 17            [X]
 
                                     AND 
                            REGISTRATION STATEMENT 
                   UNDER THE INVESTMENT COMPANY ACT OF 1940        [X]
                                                                   
 
                                AMENDMENT NO. 19                   [X]
                        (CHECK APPROPRIATE BOX OR BOXES)
                                ----------------
 
                              LOOMIS SAYLES FUNDS
               (EXACT NAME OF REGISTRANT AS SPECIFIED IN CHARTER)
 
                     ONE FINANCIAL CENTER, BOSTON, MA 02111
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)
 
       REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE: (617) 482-2450
 
                     NAME AND ADDRESS OF AGENT FOR SERVICE
                     -------------------------------------
                               SHEILA M. BARRY 
                        LOOMIS, SAYLES & COMPANY, L.P. 
                             ONE FINANCIAL CENTER 
                              BOSTON, M.A. 02111
               
                                WITH A COPY TO
                                -------------- 
                            TRUMAN S. CASNER, ESQ. 
                                 ROPES & GRAY 
                           ONE INTERNATIONAL PLACE 
                               BOSTON, MA 02110
 
  It is proposed that this filing will become effective (check appropriate box)
 
  [_]immediately upon filing pursuant to paragraph (b)
 
  [X]on December 30, 1998 pursuant to paragraph (b)
 
  [_]60 days after filing pursuant to paragraph (a)(2)
 
  [_]on [date] pursuant to paragraph (a)(1)
 
  [_]75 days after filing pursuant to paragraph (a)(2)
 
  [_]on [date] pursuant to paragraph (a)(2) of Rule 485
 
  If appropriate, check the following box:
 
  [_]This post-effective amendment designates a new effective date for a
     previously filed post-effective amendment.
 
================================================================================
<PAGE>
 
                              LOOMIS SAYLES FUNDS

                             Cross Reference Sheet

                          Items required by Form N-1A

PART A

<TABLE> 
<CAPTION> 
Item
No.  Registration Statement Caption       Caption in Prospectus               
<S>  <C>                                  <C>                                                                               
1.   Cover Page                           Cover Page                          
                                                                              
2.   Synopsis                             Summary of Expenses                 
                                                                              
3.   Condensed Financial Information      Financial Highlights                
                                                                              
4.   General Description of               Cover Page; The Trust; Investment Objectives and
     Registrant                           Policies; More Information About the Funds'        
                                          Investments and Risk Considerations 
                                                                              
5.   Management of the Fund               Cover Page; The Trust; The Funds' Investment  
                                          Adviser; Fund Expenses; Portfolio Transactions; 
                                          Back Cover  
                                                                              
5A.  Management's Discussion of           More Information about the Funds' Investments and   
     Fund Performance                     Risk Considerations; Performance Information             
                                          
6.   Capital Stock and Other Securities   The Trust; Shareholder Services; Dividends, Capital
                                          Gain Distributions and Taxes
 
7.   Purchase of Securities Being         How to Purchase Shares; Shareholder Services  
     Offered                              

8.   Redemption or Repurchase             How to Redeem Shares

9.   Pending Legal Proceedings            Not Applicable
</TABLE> 
<PAGE>
 
PART B
 
<TABLE> 
<CAPTION> 
Item
No.  Registration Statement Caption       Caption in Statement of Additional Information
<S>  <C>                                  <C>  
10.  Cover Page                           Cover Page
 
11.  Table of Contents                    Table of Contents
 
12.  General Information and History      Not Applicable
 
13.  Investment Objectives and Policies   Investment Objectives, Policies and Restrictions
 
14.  Management of the Fund               Management of the Trust
 
15.  Control Persons and Principal        Management of the Trust
     Holders of Securities

16.  Investment Advisory and Other        Investment Advisory and Other Services
     Services
 
17.  Brokerage Allocation and Other       Portfolio Transactions and Brokerage
     Practices
 
18.  Capital Stock and Other Securities   How to Redeem Shares (Prospectus); Redemptions; 
                                          Dividends, Capital Gain Distributions and Taxes 
                                          (Prospectus); Income Dividends, Capital Gain
                                          Distributions and Tax Status; Description of the 
                                          Trust
 
19.  Purchase, Redemption and Pricing     How to Purchase Shares (Prospectus); Shareholder
     of Securities Being Offered          Services; How to Redeem Shares (Prospectus);
                                          Redemptions; Net Asset Value and Public Offering
                                          Price
 
20.  Tax Status                           Dividends, Capital Gain Distributions and Taxes
                                          (Prospectus); Income Dividends, Capital Gain
                                          Distributions and Tax Status
 
21.  Underwriters                         Not Applicable
 
22.  Calculations of Performance Data     Calculation of Yield and Total Return; Performance
                                          Data
 
23.  Financial Statements                 Financial Statements
</TABLE>
<PAGE>
 
PART C

The information required to be included in Part C is set forth under the
appropriate Item, so numbered, in Part C of the Registration Statement.

This Post-Effective Amendment relates solely to the Loomis Sayles Bond Fund,
Loomis Sayles Core Value Fund, Loomis Sayles Global Bond Fund, Loomis Sayles
Growth Fund, Loomis Sayles High Yield Fund, Loomis Sayles Intermediate Maturity
Bond Fund, Loomis Sayles International Equity Fund, Loomis Sayles Investment
Grade Bond Fund, Loomis Sayles Mid-Cap Growth Fund, Loomis Sayles Mid-Cap Value
Fund, Loomis Sayles Municipal Bond Fund, Loomis Sayles Short-Term bond Fund,
Loomis Sayles Small Cap Growth Fund, Loomis Sayles Small Cap Value Fund, Loomis
Sayles Strategic Value Fund, Loomis Sayles U.S. Government Securities Fund and
Loomis Sayles Worldwide Fund, each a series of  Loomis Sayles Funds. Information
contained in the Registrant's Registration Statement relating to any other
series of the Registrant is neither amended nor superseded hereby.
<PAGE>
 
[LOGO OF LOOMIS SAYLES FUNDS APPEARS HERE] 

 ONE FINANCIAL CENTER . BOSTON, MASSACHUSETTS 02111 . (800) 633-3330
   
THE LOOMIS SAYLES FUNDS     
       
         
         
  LOOMIS SAYLES HIGH YIELD FUND
         
            
    
     INSTITUTIONAL CLASS     
        
     RETAIL CLASS     
     
  LOOMIS SAYLES U.S. GOVERNMENT SECURITIES FUND     
        
     INSTITUTIONAL CLASS     
<PAGE>
 
PROSPECTUS                                                    
                                                           JANUARY 1, 1999     
   
LOOMIS SAYLES HIGH YIELD FUND     
   
LOOMIS SAYLES U.S. GOVERNMENT SECURITIES FUND     
   
  Loomis Sayles High Yield Fund and Loomis Sayles U.S. Government Securities
Fund (the "Funds" and each a "Fund"), each a series of Loomis Sayles Funds,
are separately managed, no-load mutual funds, each of which has its own
investment objective and policies. Loomis, Sayles & Company, L.P. ("Loomis
Sayles") is the investment adviser of each Fund.     
   
  This Prospectus concisely describes the information that an investor should
know before investing in the Institutional Class shares of either Fund, and
the Retail Class shares of the High Yield Fund. Please read it carefully and
keep it for future reference. A Statement of Additional Information (SAI)
dated January 1, 1999, as revised from time to time, is available free of
charge; write to Loomis Sayles Distributors, L.P. (the "Distributor"), One
Financial Center, Boston, Massachusetts 02111 or telephone 800-633-3330. The
SAI, which contains more detailed information about the Funds, has been filed
with the Securities and Exchange Commission (the "SEC") and is available along
with other related materials on the SEC's Internet Web site
(http://www.sec.gov). The SAI is incorporated herein by reference (legally
forms a part of the Prospectus).     
 
                                            For all other information about
  For information about:                    the Funds:
   .Establishing an account                 CALL 800-633-3330
   .Account procedures and status
   .Exchanges
   .Shareholder services
  CALL 800-626-9390
 
 
  THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS
A CRIMINAL OFFENSE.
   
  THE LOOMIS SAYLES HIGH YIELD FUND WILL NORMALLY INVEST AT LEAST 65% OF ITS
TOTAL ASSETS IN LOWER-RATED SECURITIES, COMMONLY KNOWN AS "JUNK BONDS" AND MAY
INVEST SUBSTANTIALLY ALL OF ITS ASSETS IN SUCH SECURITIES. INVESTMENTS OF THIS
TYPE ARE SUBJECT TO A GREATER RISK OF LOSS OF PRINCIPAL AND NON-PAYMENT OF
INTEREST. INVESTORS SHOULD ASSESS CAREFULLY THE RISKS ASSOCIATED WITH AN
INVESTMENT IN THE LOOMIS SAYLES HIGH YIELD FUND. SEE "MORE INFORMATION ABOUT
THE FUNDS' INVESTMENTS AND RISK CONSIDERATIONS--LOWER RATED FIXED INCOME
SECURITIES" AND "APPENDIX A."     
 
                                       1
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>   
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
SUMMARY OF EXPENSES.......................................................   3
FINANCIAL HIGHLIGHTS......................................................   5
THE TRUST.................................................................   8
INVESTMENT OBJECTIVES AND POLICIES........................................   8
MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS AND RISK CONSIDERATIONS.....   9
THE FUNDS' INVESTMENT ADVISER.............................................  20
FUND EXPENSES.............................................................  20
PORTFOLIO TRANSACTIONS....................................................  21
HOW TO PURCHASE SHARES....................................................  21
SHAREHOLDER SERVICES......................................................  24
HOW TO REDEEM SHARES......................................................  25
CALCULATION OF PERFORMANCE INFORMATION....................................  27
DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES...........................  27
APPENDIX A
  DESCRIPTION OF BOND RATINGS.............................................  29
</TABLE>    
 
                                       2
<PAGE>
 
                              SUMMARY OF EXPENSES
           (FOR AN INSTITUTIONAL CLASS SHARE OF EACH INDICATED FUND)
   
  The following information is provided as an aid in understanding the various
expenses that an investor in a Fund will bear indirectly. The information
below is based on expenses for the Funds' most recent fiscal year, and should
not be considered a representation of past or future expenses, as actual
expenses may be greater or less than those shown. Also, the 5% annual return
assumed in the Example should not be considered a representation of investment
performance, as actual performance will vary.     
 
<TABLE>   
<CAPTION>
                                                                          U.S.
                                                                HIGH   GOVERNMENT
                                                                YIELD  SECURITIES
                                                                FUND      FUND
                                                                -----  ----------
 <S>                                                            <C>    <C>
 Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on Purchases (as % of offering
  price)......................................................  none      none
 Maximum Sales Load Imposed on Reinvested Dividends (as % of
  offering price).............................................  none      none
 Maximum Deferred Sales Load (as % of original purchase price
  or redemption proceeds).....................................  none      none
 Redemption Fees/1............................................  2.00%     none
 Exchange Fees................................................  none      none
 Annual Fund Operating Expenses (as a percentage of average
  net assets):
 Management Fees..............................................   .60%      .30%
 12b-1 Fees...................................................  none      none
 Other Operating Expenses (after expense reimbursements where
  indicated)..................................................   .15%/2/   .20%/2/
 Total Fund Operating Expenses (after expense reimbursements
  where indicated)............................................   .75%/2/   .50%/2/
 Example:
 An investor would pay the following expenses on a $1,000
  investment assuming a 5% annual return (with or without a
  redemption at the end of each time period):
 One Year.....................................................  $  8      $  6
 Three Years..................................................  $ 24      $ 19
 Five Years...................................................  $ 42      $ 33
 Ten Years....................................................  $ 93      $ 75
</TABLE>    

- -----------
   
/1/ A $5 charge applies to any wire transfer of redemption proceeds from each
    Fund. A 2.00% redemption fee applies with respect to shares of the High
    Yield Fund redeemed within one (1) year of purchase. Loomis Sayles may, in
    its discretion, waive redemption fees on shares of the High Yield Fund as
    set forth under the heading "How to Redeem Shares" if it determines that
    there are minimal brokerage and transaction costs incurred in connection
    with the redemption.     
   
/2/ Loomis Sayles has voluntarily agreed, for an indefinite period, to limit the
    Funds' Total Operating Expenses to the percentages of net assets shown in
    the table. Without this agreement, Other Operating Expenses and Total
    Operating Expenses would have been 1.82% and 2.42%, respectively, for the
    High Yield Fund, 0.67% and 0.97%, respectively, for the U.S. Government
    Securities Fund.     
 
                                       3
<PAGE>
 
                              SUMMARY OF EXPENSES
               
            (FOR A RETAIL CLASS SHARE OF THE HIGH YIELD FUND)     
   
  The following information is provided as an aid in understanding the various
expenses that an investor in the Fund will bear indirectly. The information is
based on expenses for the Funds' most recent fiscal year, and should not be
considered a representation of past or future expenses, as actual expenses may
be greater or less than those shown. Also, the 5% annual return assumed in the
Example should not be considered a representation of investment performance,
as actual performance will vary.     
 
<TABLE>   
<CAPTION>
                                                                     HIGH YIELD
                                                                        FUND
                                                                     ----------
<S>                                                                  <C>
Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on Purchases (as % of offering price)...    none
 Maximum Sales Load Imposed on Reinvested Dividends (as % of
   offering price)..................................................    none
 Maximum Deferred Sales Load (as % of original purchase price or
   redemption proceeds).............................................    none
 Redemption Fees/1..................................................    2.00%
 Exchange Fees......................................................    none
Annual Fund Operating Expenses (as a percentage of average
  net assets):
 Management Fees....................................................     .60%
 12b-1 Fees.........................................................     .25%
 Other Operating Expenses (after expense reimbursements where
   indicated).......................................................     .15%/2/
 Total Fund Operating Expenses (after expense reimbursements where
   indicated).......................................................    1.00%/2/
Example:
An investor would pay the following expenses on a $1,000 investment
  assuming a 5% annual return (with or without a redemption at the
  end of each time period):
 One Year...........................................................    $ 10
 Three Years........................................................    $ 32
 Five Years.........................................................    $ 55
 Ten Years..........................................................    $122
</TABLE>    
- -----------
   
/1/ A $5 charge applies to any wire transfer of redemption proceeds from any
    Fund. A 2.00% redemption fee applies with respect to shares of the High
    Yield Fund redeemed within one (1) year of purchase. Loomis Sayles may, in
    its discretion, waive redemption fees on shares of the High Yield Fund as
    set forth under the heading "How to Redeem Shares" if it determines that
    there are minimal brokerage and transaction costs incurred in connection
    with the redemption.     
   
/2/ Loomis Sayles has voluntarily agreed, for an indefinite period, to limit the
    Fund's Total Operating Expenses to the percentages of average net assets
    shown in the table. Without this agreement, Other Operating Expenses
    (including 12b-1 fees) and Total Operating Expenses would have been 2.07%
    and 2.67%.     
 
                                       4
<PAGE>
 
                             FINANCIAL HIGHLIGHTS
           (FOR AN INSTITUTIONAL CLASS SHARE OF EACH INDICATED FUND
                 OUTSTANDING THROUGHOUT THE INDICATED PERIODS)
   
  The financial highlights tables that follow have been audited by
PricewaterhouseCoopers LLP, independent accountants. The following information
should be read in conjunction with the financial highlights, financial
statements and the notes thereto contained in the Funds' 1998 Annual Report,
which is incorporated by reference in this Prospectus and the Statement of
Additional Information.     
       
<TABLE>   
<CAPTION>
                                                HIGH YIELD FUND--INSTITUTIONAL
                                                             CLASS
                                               ---------------------------------
                                                   NINE                SEP. 11**
                                               MONTHS ENDED YEAR ENDED    TO
                                                SEPT. 30*,   DEC. 31,  DEC. 31,
                                                   1998        1997      1996
                                               ------------ ---------- ---------
<S>                                            <C>          <C>        <C>
Net asset value, beginning of period.........     $10.12      $10.11    $10.00
                                                  ------      ------    ------
Income from investment operations--
 Net investment income (loss)................       0.78 ++     0.83      0.20
 Net realized and unrealized gain (loss) on
  investments................................      (2.28)       0.27      0.11
                                                  ------      ------    ------
 Total from investment operations............      (1.50)       1.10      0.31
                                                  ------      ------    ------
Less distributions--
 Dividends from net investment income........      (0.46)      (0.86)    (0.20)
 Distributions from net realized capital
  gains......................................       0.00       (0.26)     0.00
                                                  ------      ------    ------
 Total distributions.........................      (0.46)      (1.12)    (0.20)
                                                  ------      ------    ------
 Redemption Fees.............................       0.01        0.03      0.00
                                                  ------      ------    ------
Net asset value, end of period...............     $ 8.17      $10.12    $10.11
                                                  ======      ======    ======
Total return (%)***..........................      (15.6)+++    11.4       3.1
Net assets, end of period (000)..............     $6,624      $5,266    $1,939
Ratio of operating expenses to average net
 assets (%)****..............................       0.75 +      0.75      0.75+
Ratio of net investment income to average net
 assets (%)..................................      10.54 +      8.96      8.85+
Portfolio turnover rate (%)..................         33+++       68         0
Without giving effect to voluntary expense
 limitations:
 The ratio of operating expenses to average
  net assets would have been (%).............       2.42 +      3.81     12.06+
 Net investment income per share would have
  been.......................................     $ 0.65 ++   $ 0.54    $(0.05)
</TABLE>    

- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
   
  ++ Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
    
 +++ Periods less than one year are not annualized.     
 
                                       5
<PAGE>
 
<TABLE>   
<CAPTION>
                                 U.S. GOVERNMENT SECURITIES FUND--INSTITUTIONAL CLASS
                          -------------------------------------------------------------------------
                             NINE
                            MONTHS                                                         MAY 21**
                            ENDED                  YEAR ENDED DEC. 31,                        TO
                          SEPT. 30*, ----------------------------------------------------  DEC. 31,
                             1998     1997     1996     1995     1994     1993     1992      1991
                          ---------- -------  -------  -------  -------  -------  -------  --------
<S>                       <C>        <C>      <C>      <C>      <C>      <C>      <C>      <C>
Net asset value,
 beginning of period....   $ 10.70   $ 10.08  $ 10.64  $  9.22  $ 10.53  $ 10.45  $ 10.77   $10.00
                           -------   -------  -------  -------  -------  -------  -------   ------
Income from investment
 operations--
 Net investment income..      0.43      0.63     0.68     0.66     0.64     0.64     0.64     0.40
 Net realized and
  unrealized gain (loss)
  on investments........      0.58      0.61    (0.57)    1.42    (1.30)    1.00     0.27     1.11
                           -------   -------  -------  -------  -------  -------  -------   ------
 Total from investment
  operations............      1.01      1.24     0.11     2.08    (0.66)    1.64     0.91     1.51
                           -------   -------  -------  -------  -------  -------  -------   ------
Less distributions--
 Dividends from net
  investment income.....     (0.30)    (0.62)   (0.67)   (0.66)   (0.65)   (0.65)   (0.59)   (0.40)
 Distributions from net
  realized capital
  gains.................      0.00      0.00     0.00     0.00     0.00    (0.91)   (0.64)   (0.34)
                           -------   -------  -------  -------  -------  -------  -------   ------
 Total distributions....     (0.30)    (0.62)   (0.67)   (0.66)   (0.65)   (1.56)   (1.23)   (0.74)
                           -------   -------  -------  -------  -------  -------  -------   ------
Net asset value, end of
 period.................   $ 11.41   $ 10.70  $ 10.08  $ 10.64  $  9.22  $ 10.53  $ 10.45   $10.77
                           =======   =======  =======  =======  =======  =======  =======   ======
Total return (%)***.....       9.6++    12.7      1.3     23.0     (6.3)    15.7      8.8     15.3
Net assets, end of
 period (000)...........   $29,246   $17,668  $14,192  $19,499  $17,341  $18,317  $10,899   $6,248
Ratio of operating
 expenses to average net
 assets (%)****.........      0.60+     0.60     1.00     1.00     1.00     1.00     1.00     1.00+
Ratio of net investment
 income to average net
 assets (%).............      5.61+     6.29     6.23     6.47     6.60     5.95     6.54     7.01+
Portfolio turnover rate
 (%)....................        84++     156      137      169      242      277      344      273
Without giving effect to
 voluntary expense
 limitations:
 The ratio of operating
  expenses to average
  net assets would have
  been (%)..............      0.97+     1.23     1.19     1.22     1.22     1.29     2.01     2.39+
 Net investment income
  per share would have
  been..................   $  0.40   $  0.57  $  0.66  $  0.64  $  0.62  $  0.61  $  0.54   $ 0.32
</TABLE>    

- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
   + Computed on an annualized basis.     
    
  ++ Periods less than one year are not annualized.     
       
                                       6
<PAGE>
 
                             FINANCIAL HIGHLIGHTS
                
             (FOR A RETAIL CLASS SHARE OF THE HIGH YIELD FUND     
                 OUTSTANDING THROUGHOUT THE INDICATED PERIODS)
   
  The financial highlights that follow have been audited by Pricewaterhouse-
Coopers LLP, independent accountants. The information should be read in
conjunction with the financial highlights, financial statements and the notes
thereto contained in the Funds' 1998 Annual Report, which is incorporated by
reference in this Prospectus and the Statement of Additional Information.     
 
<TABLE>   
<CAPTION>
                                                            HIGH YIELD FUND--
                                                              RETAIL CLASS
                                                          ----------------------
                                                             NINE
                                                            MONTHS      JAN. 2**  
                                                            ENDED          TO     
                                                          SEPT. 30*,    DEC. 31,  
                                                             1998         1997    
                                                          ----------    --------  
<S>                                                       <C>           <C>       
Net asset value, beginning of period....................    $10.12       $10.11   
                                                            ------       ------   
Income from investment operations--                                               
 Net investment income (loss)...........................      0.75***      0.85***
 Net realized and unrealized gain (loss) on                                       
  investments...........................................     (2.27)        0.23   
                                                            ------       ------   
 Total from investment operations.......................     (1.52)        1.08   
                                                            ------       ------   
Less distributions--                                                              
 Dividends from net investment income...................     (0.45)       (0.84)  
 Distributions from net realized capital gains..........      0.00        (0.26)  
                                                            ------       ------   
 Total distributions....................................     (0.45)       (1.10)  
                                                            ------       ------   
Redemption Fees.........................................      0.01         0.03   
                                                            ------       ------   
Net asset value, end of period..........................    $ 8.16       $10.12   
                                                            ======       ======   
Total return (%)****....................................     (15.8)+++     11.2   
Net assets, end of period (000).........................    $4,020       $3,141   
Ratio of operating expenses to average net assets (%)+..      1.00++       1.00++ 
Ratio of net investment income to average net assets                              
 (%)....................................................     10.17++       8.75++ 
Portfolio turnover rate (%).............................        33+++        68   
Without giving effect to voluntary expense limitations:                           
 The ratios of operating expenses to average net assets                           
  would have been (%)...................................      2.67++       4.79++ 
 Net investment income per share would have been........    $ 0.63***    $ 0.48*** 
</TABLE>    

- -----------
   
   *  The Fund's fiscal year-end changed to September 30 from December 31.     
   
  **  Commencement of investment operations.     
   
 ***  Per share net investment income has been determined on the basis of the
      weighted average number of shares outstanding during the period.     
   
****  Total returns would have been lower had the adviser not reduced its
      advisory fee and/or borne other operating expenses.     
   +  The adviser has agreed to reimburse a portion of the Fund's expenses
      during the period. Without this reimbursement, the Fund's ratio of
      operating expenses would have been higher.
  ++  Computed on an annualized basis.
    
 +++  Periods less than one year are not annualized.     
   
NOTE: Further information about each Fund's performance is contained in the
      Funds' annual report to shareholders, which may be obtained without
      charge.     
 
                                       7

<PAGE>
 
                                   THE TRUST
 
  Each Fund is a series of Loomis Sayles Funds (the "Trust"). The Trust is a
diversified open-end management investment company organized as a
Massachusetts business trust on February 20, 1991. The Trust is authorized to
issue an unlimited number of full and fractional shares of beneficial interest
in multiple series. Shares are freely transferable and entitle shareholders to
receive dividends as determined by the Trust's board of trustees and to cast a
vote for each share held at shareholder meetings. The Trust does not generally
hold shareholder meetings and will do so only when required by law.
Shareholders may call meetings to consider removal of the Trust's trustees.
 
                      INVESTMENT OBJECTIVES AND POLICIES
       
LOOMIS SAYLES HIGH YIELD FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
   
  The Fund seeks to achieve its objective by normally investing substantially
all of its assets in fixed income securities, although up to 20% of its total
assets may be invested in preferred stocks and up to 10% of its total assets
may be invested in common stocks. The fixed income securities in which the
Fund may invest include corporate securities, U.S. Government Securities,
commercial paper, zero coupon securities, mortgage-backed securities, CMOs,
asset-backed securities, when-issued securities, real estate investment trusts
("REITs"), Rule 144A securities, repurchase agreements and convertible
securities. The Fund may engage in options and futures transactions,
repurchase transactions, foreign currency hedging transactions and swap
transactions. The Fund may invest any portion of its assets in securities of
Canadian issuers and up to 50% of its total assets in the securities of other
foreign issuers.     
   
  The Fund will normally invest at least 65% of its total assets in fixed
income securities of below investment grade quality (commonly referred to as
"junk bonds").     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
                                       8
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
   <S>                                                          <C>      <C>
   AAA/Aaa.....................................................
   AA/Aa.......................................................
   A/A.........................................................
   BBB/Baa.....................................................
   BB/Ba.......................................................
   B/B.........................................................
   CCC/Caa.....................................................
   C/Ca........................................................
   D...........................................................
</TABLE>    
 
LOOMIS SAYLES U.S. GOVERNMENT SECURITIES FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
 
  The Fund seeks to achieve its objective by investing substantially all its
assets in U.S. Government Securities and in certificates representing
undivided interests in the interest or principal of U.S. Treasury securities.
At least 65% of the Fund's total assets will normally be invested in U.S.
Government Securities.
 
ALL FUNDS
 
  For temporary defensive purposes, each Fund may invest any portion of its
assets in fixed income securities, cash or any other securities deemed
appropriate by Loomis Sayles.
 
  Except for each Fund's investment objective, and any investment policies
that are identified as "fundamental," all of the investment policies of each
Fund may be changed without a vote of Fund shareholders.
 
                 MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS
                            AND RISK CONSIDERATIONS
 
DEBT AND OTHER FIXED INCOME SECURITIES
   
  Each of the Funds may invest in fixed income securities of any maturity.
Fixed income securities pay a specified rate of interest or dividends, or a
rate that is adjusted periodically by reference to some specified index or
market rate. Fixed income securities include securities issued by federal,
state, local and foreign governments and related agencies, and by a wide range
of private issuers. Because interest rates vary, it is impossible to predict
the income of a Fund that invests in fixed income securities for any
particular period. The net asset value of such a Fund's shares will vary as a
result of changes in the value of the securities in the Fund's portfolio.     
 
 
                                       9
<PAGE>
 
  Fixed income securities are subject to market and credit risk. Market risk
relates to changes in a security's value as a result of changes in interest
rates generally. In general, the values of fixed income securities increase
when prevailing interest rates fall and decrease when interest rates rise.
Credit risk relates to the ability of the issuer to make payments of principal
and interest.
 
U.S. GOVERNMENT SECURITIES
 
  U.S. Government Securities have different kinds of government support. For
example, some U.S. Government Securities, such as U.S. Treasury bonds, are
supported by the full faith and credit of the United States, whereas certain
other U.S. Government Securities issued or guaranteed by federal agencies or
government-sponsored enterprises are not supported by the full faith and
credit of the United States.
 
  Although U.S. Government Securities generally do not involve the credit
risks associated with other types of fixed income securities, the market
values of U.S. Government Securities do go up and down as interest rates
change. Thus, for example, the value of an investment in a Fund that holds
U.S. Government Securities may fall during times of rising interest rates.
Yields on U.S. Government Securities tend to be lower than those on corporate
securities of comparable maturities.
 
  Some U.S. Government Securities, such as Government National Mortgage
Association Certificates ("GNMA"), are known as "mortgage-backed" securities.
Interest and principal payments on the mortgages underlying mortgage-backed
U.S. Government Securities are passed through to the holders of the security.
If a Fund purchases mortgage-backed securities at a discount or a premium, the
Fund will recognize a gain or loss when the payments of principal, through
prepayment or otherwise, are passed through to the Fund and, if the payment
occurs in a period of falling interest rates, the Fund may not be able to
reinvest the payment at as favorable an interest rate. As a result of these
principal prepayment features, mortgage-backed securities are generally more
volatile investments than many other fixed income securities.
 
  In addition to investing directly in U.S. Government Securities, the Funds
may purchase certificates of accrual or similar instruments ("strips")
evidencing undivided ownership interests in interest payments or principal
payments, or both, in U.S. Government Securities. These investment instruments
may be highly volatile.
 
TAX EXEMPT SECURITIES
 
  Issuers of tax exempt securities may make interest and principal payments
from money raised through a variety of sources, including (1) the issuer's
 
                                      10
<PAGE>
 
general taxing power, (2) a specific type of tax, such as a property tax, or
(3) a particular facility or project, such as a highway. The ability of an
issuer of tax exempt bonds to make these payments could be affected by
litigation, legislation or other political events, or the bankruptcy of the
issuer. The interest on tax exempt securities issued after August 15, 1986 is
retroactively taxable from the date of issuance if the issuer does not comply
with certain requirements concerning the use of bond proceeds and the
application of earnings on bond proceeds.
 
LOWER RATED FIXED INCOME SECURITIES
   
  The High Yield Fund may invest a portion of its assets in securities rated
below investment grade (commonly referred to as "junk bonds"). The Fund will
normally invest at least 65% of its total assets in such securities. For
purposes of the foregoing percentages, a security will be treated as being of
investment grade quality if at the time a Fund acquires it at least one major
rating agency has rated the security in its top four rating categories (even
if another such agency has issued a lower rating), or if the security is
unrated but Loomis Sayles determines it to be of investment grade quality.
Lower rated fixed income securities generally provide higher yields, but are
subject to greater credit and market risk, than higher quality fixed income
securities. Lower rated fixed income securities are considered predominantly
speculative with respect to the ability of the issuer to meet principal and
interest payments. Achievement of the investment objective of a Fund investing
in lower rated fixed income securities may be more dependent on Loomis Sayles'
own credit analysis than is the case with higher quality bonds. The market for
lower rated fixed income securities may be more severely affected than some
other financial markets by economic recession or substantial interest rate
increases, by changing public perceptions of this market or by legislation
that limits the ability of certain categories of financial institutions to
invest in these securities. In addition, the secondary market may be less
liquid for lower rated fixed income securities. This lack of liquidity at
certain times may affect the values of these securities and may make the
evaluation and sale of these securities more difficult. Securities in the
lowest rating categories may be in poor standing or in default. Securities in
the lowest investment grade category (BBB or Baa) have some speculative
characteristics.     
 
  For more information about the ratings services' descriptions of the various
rating categories, see Appendix A.
 
COMMON STOCKS AND OTHER EQUITY SECURITIES
 
  Common stocks and similar equity securities, such as warrants and
convertibles, are volatile and more risky than some other forms of investment.
The value of an investment in a Fund that invests in equity securities may
 
                                      11
<PAGE>
 
sometimes decrease. Equity securities of companies with relatively small
market capitalization may be more volatile than the securities of larger, more
established companies and than the broad equity market indexes.
 
ZERO COUPON SECURITIES
 
  Each Fund may invest in "zero coupon" fixed income securities. These
securities accrue interest at a specified rate, but do not pay interest in
cash on a current basis. A Fund investing in zero coupon securities is
required to distribute the income on these securities to Fund shareholders as
the income accrues, even though the Fund is not receiving the income in cash
on a current basis. Thus the Fund may have to sell other investments to obtain
cash to make income distributions at times when Loomis Sayles would not
otherwise deem it advisable to do so. The market value of zero coupon
securities is often more volatile than that of non-zero coupon fixed income
securities of comparable quality and maturity.
 
MORTGAGE-BACKED SECURITIES
   
  Each Fund may invest in mortgage-backed securities, such as GNMA or Fannie
Mae certificates, which differ from traditional debt securities. Among the
major differences are that interest and principal payments are made more
frequently, usually monthly, and that principal may be prepaid at any time
because the underlying mortgage loans generally may be prepaid at any time. As
a result, if a Fund purchases these assets at a premium, a faster-than-
expected prepayment rate will reduce yield to maturity, and a slower-than-
expected prepayment rate will increase yield to maturity. If a Fund purchases
mortgage-backed securities at a discount, faster-than-expected prepayments
will increase, and slower-than-expected prepayments will reduce, yield to
maturity. Prepayments, and resulting amounts available for reinvestment by the
Fund, are likely to be greater during a period of declining interest rates
and, as a result, are likely to be reinvested at lower interest rates.
Accelerated prepayments on securities purchased at a premium may result in a
loss of principal if the premium has not been fully amortized at the time of
prepayment. Although these securities will decrease in value as a result of
increases in interest rates generally, they are likely to appreciate less than
other fixed-income securities when interest rates decline because of the risk
of prepayments.     
 
STRIPPED MORTGAGE-BACKED SECURITIES
 
  Each Fund may invest in interest-only and principal-only classes of
mortgage-backed securities ("IOs" and "POs"). The yield to maturity on an IO
or PO is extremely sensitive not only to changes in prevailing interest rates
but also to the rate of principal payments (including prepayments) on the
underlying assets. A rapid rate of principal prepayments may have a measurably
 
                                      12
<PAGE>
 
adverse effect on a Fund's yield to maturity to the extent it invests in IOs.
If the assets underlying the IOs experience greater than anticipated
prepayments of principal, the Fund may fail to recoup fully its initial
investment in these securities. Conversely, POs tend to increase in value if
prepayments are greater than anticipated and decline if prepayments are slower
than anticipated.
 
  The secondary market for stripped mortgage-backed securities may be more
volatile and less liquid than that for other mortgage-backed securities,
potentially limiting a Fund's ability to buy or sell those securities at any
particular time.
 
COLLATERALIZED MORTGAGE OBLIGATIONS
   
  Each Fund may invest in CMOs. A CMO is a security backed by a portfolio of
mortgages or mortgage-backed securities held under an indenture. CMOs may be
issued either by U.S. Government instrumentalities or by non-governmental
entities. The issuer's obligation to make interest and principal payments is
secured by the underlying portfolio of mortgages or mortgage-backed
securities. CMOs are issued with a number of classes or series which have
different maturities and which may represent interests in some or all of the
interest or principal on the underlying collateral or a combination thereof.
CMOs of different classes are generally retired in sequence as the underlying
mortgage loans in the mortgage pool are repaid. In the event of sufficient
early prepayments on such mortgages, the class or series of CMOs first to
mature generally will be retired prior to its maturity. As with other
mortgage-backed securities, the early retirement of a particular class or
series of CMOs held by a Fund could involve the loss of any premium the Fund
paid when it acquired the investment and could result in the Fund's
reinvesting the proceeds at a lower interest rate than the retired CMO paid.
Because of the early retirement feature, CMOs may be more volatile than many
other fixed-income investments.     
 
ASSET-BACKED SECURITIES
   
  The High Yield Fund may invest in asset-backed securities. Through the use
of trusts and special purpose corporations, automobile and credit card
receivables are securitized in pass-through structures similar to mortgage
pass-through structures or in a pass-through structure similar to the CMO
structure. Generally, the issuers of asset-backed bonds, notes or pass-through
certificates are special purpose entities and do not have any significant
assets other than the receivables securing such obligations. In general, the
collateral supporting asset-backed securities is of shorter maturity than
mortgage loans. Instruments backed by pools of receivables are similar to
mortgage-backed securities in that they are subject to unscheduled prepayments
of principal prior to maturity. When the obligations are prepaid, the Fund
will ordinarily reinvest the prepaid amounts in securities the yields of which
reflect interest rates prevailing at the time.     
 
                                      13
<PAGE>
 
   
Therefore, the Fund's ability to maintain a portfolio that includes high-
yielding asset-backed securities will be adversely affected to the extent that
prepayments of principal must be reinvested in securities that have lower
yields than the prepaid obligations. Moreover, prepayments of securities
purchased at a premium could result in a realized loss.     
 
WHEN-ISSUED SECURITIES
 
  Each Fund may purchase securities on a "when-issued" basis. This means that
the Fund will enter into a commitment to buy the security before the security
has been issued. The Fund's payment obligation and the interest rate on the
security are determined when the Fund enters into the commitment. The security
is typically delivered to the Fund 15 to 120 days later. No interest accrues
on the security between the time the Fund enters into the commitment and the
time the security is delivered. If the value of the security being purchased
falls between the time a Fund commits to buy it and the payment date, the Fund
may sustain a loss. The risk of this loss is in addition to the Fund's risk of
loss on the securities actually in its portfolio at the time. In addition,
when the Fund buys a security on a when-issued basis, it is subject to the
risk that market rates of interest will increase before the time the security
is delivered, with the result that the yield on the security delivered to the
Fund may be lower than the yield available on other, comparable securities at
the time of delivery. If a Fund has outstanding obligations to buy when-issued
securities, it will maintain liquid assets in a segregated account at its
custodian bank in an amount sufficient to satisfy these obligations.
   
CONVERTIBLE SECURITIES     
   
  The High Yield Fund may invest in convertible securities. Convertible
securities include corporate bonds, notes or preferred stocks of U.S. or
foreign issuers that can be converted into (that is, exchanged for) common
stocks or other equity securities at a stated price or rate. Convertible
securities also include other securities, such as warrants, that provide an
opportunity for equity participation. Because convertible securities can be
converted into equity securities, their value will normally vary in some
proportion with those of the underlying equity securities. Convertible
securities usually provide a higher yield than the underlying equity security,
however, so that when the price of the underlying equity security falls, the
decline in the price of the convertible security may sometimes be less
substantial than that of the underlying equity security. Due to the conversion
feature, convertible securities generally yield less than nonconvertible fixed
income securities of similar credit quality and maturity. The Fund's
investment in convertible securities may at times include securities that have
a mandatory conversion feature, pursuant to which the securities convert
automatically into common stock at a specified date and conversion ratio, or
that are convertible at the option of the issuer. Because     
 
                                      14
<PAGE>
 
   
conversion is not at the option of the holder, the Fund may be required to
convert the security into the underlying common stock even at times when the
value of the underlying common stock has declined substantially.     
   
REAL ESTATE INVESTMENT TRUSTS     
   
  The High Yield Fund may invest in REITs. REITs involve certain unique risks
in addition to those risks associated with investing in the real estate
industry in general (such as possible declines in the value of real estate,
lack of availability of mortgage funds or extended vacancies of property).
Equity REITs may be affected by changes in the value of the underlying
property owned by the REITs, while mortgage REITs may be affected by the
quality of any credit extended. REITs are dependent upon management skills,
are not diversified, are subject to heavy cash flow dependency, risks of
default by borrowers and self-liquidation. REITs are also subject to the
possibilities of failing to qualify for tax-free pass-though of income under
the Code, and failing to maintain their exemptions from registration under the
Investment Company Act of 1940 (the "1940 Act").     
   
  Investment in REITs involves risk similar to those associated with investing
in small capitalization companies. REITs may have limited financial resources,
may trade less frequently and in a limited volume and may be subject to more
abrupt or erratic price movements than larger securities.     
 
RULE 144A SECURITIES
 
  Each Fund may invest in Rule 144A securities, which are privately offered
securities that can be resold only to certain qualified institutional buyers.
Rule 144A securities are treated as illiquid, unless Loomis Sayles has
determined, under guidelines established by the Trust's trustees, that the
particular issue of Rule 144A securities is liquid.
 
FOREIGN SECURITIES
   
  The High Yield Fund may invest in securities of issuers organized or
headquartered outside the United States ("foreign securities"). The Fund may
invest any portion of its assets in securities of Canadian issuers and up to
50% of its total assets in the securities of other foreign issuers.     
   
  Although investing in foreign securities may increase the Fund's
diversification and reduce portfolio volatility, foreign securities may
present risks not associated with investments in comparable securities of U.S.
issuers. There may be less information publicly available about a foreign
corporate or government issuer than about a U.S. issuer, and foreign corporate
issuers are not generally subject to accounting, auditing and financial
reporting standards and     
 
                                      15
<PAGE>
 
   
practices comparable to those in the United States. The securities of some
foreign issuers are less liquid and at times more volatile than securities of
comparable U.S. issuers. Foreign brokerage commissions and securities custody
costs are often higher than in the United States. With respect to certain
foreign countries, there is a possibility of governmental expropriation of
assets, confiscatory taxation, political or financial instability and
diplomatic developments that could affect the value of investments in those
countries. The Fund's receipt of interest on foreign government securities may
depend on the availability of tax or other revenues to satisfy the issuer's
obligations.     
   
  The Fund's investments in foreign securities may include investments in
countries whose economies or securities markets are not yet highly developed.
Special considerations associated with these investments (in addition to the
considerations regarding foreign investments generally) may include, among
others, greater political uncertainties, an economy's dependence on revenues
from particular commodities or on international aid or development assistance,
currency transfer restrictions, highly limited numbers of potential buyers for
such securities and delays and disruptions in securities settlement
procedures.     
   
  Since most foreign securities are denominated in foreign currencies or
traded primarily in securities markets in which settlements are made in
foreign currencies, the value of these investments and the net investment
income available for distribution to shareholders of the Fund investing in
these securities may be affected favorably or unfavorably by changes in
currency exchange rates, exchange control regulations or foreign withholding
taxes. Changes in the value relative to the U.S. dollar of a foreign currency
in which the Fund's holdings are denominated will result in a change in the
U.S. dollar value of the Fund's assets and the Fund's income available for
distribution.     
   
  In addition, although part of the Fund's income may be received or realized
in foreign currencies, the Fund will be required to compute and distribute its
income in U.S. dollars. Therefore, if the value of a currency relative to the
U.S. dollar declines after the Fund's income has been earned in that currency,
translated into U.S. dollars and declared as a dividend, but before payment of
the dividend, the Fund could be required to liquidate portfolio securities to
pay the dividend. Similarly, if the value of a currency relative to the U.S.
dollar declines between the time the Fund accrues expenses in U.S. dollars and
the time such expenses are paid, the amount of such currency required to be
converted into U.S. dollars will be greater than the equivalent amount in such
currency of such expenses at the time they were incurred.     
 
  In determining whether to invest assets of the Funds in securities of a
particular foreign issuer, Loomis Sayles will consider the likely effects of
foreign taxes on the net yield available to the Fund and its shareholders.
 
                                      16
<PAGE>
 
Compliance with foreign tax law may reduce a Fund's net income available for
distribution to shareholders.
 
FOREIGN CURRENCY HEDGING TRANSACTIONS
   
  The High Yield Fund may engage in foreign currency exchange transactions to
protect the value of specific portfolio positions or in anticipation of
changes in relative values of currencies in which current or future Fund
portfolio holdings are denominated or quoted. For example, to protect against
a change in the foreign currency exchange rate between the date on which a
Fund contracts to purchase or sell a security and the settlement date for the
purchase or sale, or to "lock in" the equivalent of a dividend or interest
payment in another currency, a Fund might purchase or sell a foreign currency
on a spot (that is, cash) basis at the prevailing spot rate. If conditions
warrant, the Funds may also enter into private contracts to purchase or sell
foreign currencies at a future date ("forward contracts"). The Funds might
also purchase exchange-listed and over-the-counter call and put options on
foreign currencies. Over-the-counter currency options are generally less
liquid than exchange-listed options, and will be treated as illiquid assets.
The Funds may not be able to dispose of over-the-counter options readily.     
 
  Foreign currency transactions involve costs and may result in losses.
 
SWAP TRANSACTIONS
   
  The High Yield Fund may enter into interest rate or currency swaps. The
Funds will enter into these transactions primarily to preserve a return or
spread on a particular investment or portion of its portfolio, to protect
against currency fluctuations, as a duration management technique or to
protect against any increase in the price of securities a Fund anticipates
purchasing at a later date. Interest rate swaps involve the exchange by a Fund
with another party of their respective commitments to pay or receive interest
(for example, an exchange of floating rate payments for fixed rate payments
with respect to a notional amount of principal). A currency swap is an
agreement to exchange cash flows on a notional amount based on changes in the
relative values of the specified currencies. The Fund will maintain liquid
assets in a segregated custodial account to cover its current obligations
under swap agreements. Because swap agreements are not exchange-traded, but
are private contracts into which the Fund and a swap counterparty enter as
principals, the Fund may experience a loss or delay in recovering assets if
the counterparty were to default on its obligations.     
 
OPTIONS AND FUTURES TRANSACTIONS
   
  The High Yield Fund may buy, sell or write options on securities, securities
indexes, currencies or futures contracts and may buy and sell futures
contracts     
 
                                      17
<PAGE>
 
   
on securities, securities indexes or currencies. The Fund may engage in these
transactions either for the purpose of enhancing investment return, or to
hedge against changes in the value of other assets that the Fund own or intend
to acquire. Options and futures fall into the broad category of financial
instruments known as "derivatives" and involve special risks. Use of options
or futures for other than hedging purposes may be considered a speculative
activity, involving greater risks than are involved in hedging.     
   
  Options can generally be classified as either "call" or "put" options. There
are two parties to a typical options transaction: the "writer" and the
"buyer." A call option gives the buyer the right to buy a security or other
asset (such as an amount of currency or a futures contract) from, and a put
option gives the buyer the right to sell a security or other asset to, the
option writer at a specified price, on or before a specified date. The buyer
of an option pays a premium when purchasing the option, which reduces the
return on the underlying security or other asset if the option is exercised,
and results in a loss if the option expires unexercised. The writer of an
option receives a premium from writing an option, which may increase its
return if the option expires or is closed out at a profit. If the Fund as the
writer of an option is unable to close out an unexpired option, it must
continue to hold the underlying security or other asset until the option
expires, to "cover" its obligation under the option.     
   
  A futures contract creates an obligation by the seller to deliver and the
buyer to take delivery of the type of instrument or cash at the time and in
the amount specified in the contract. Although many futures contracts call for
the delivery (or acceptance) of the specified instrument, futures are usually
closed out before the settlement date through the purchase (or sale) of a
comparable contract. If the price of the sale of the futures contract by the
Fund exceeds (or is less than) the price of the offsetting purchase, the Fund
will realize a gain (or loss).     
   
  The value of options purchased by the Fund and futures contracts held by the
Fund may fluctuate based on a variety of market and economic factors. In some
cases, the fluctuations may offset (or be offset by) changes in the value of
securities held in the Fund's portfolio. All transactions in options and
futures involve the possible risk of loss to the Fund of all or a significant
part of the value of its investment. In some cases, the risk of loss may
exceed the amount of the Fund's investment. When the Fund writes a call option
or sells a futures contract without holding the underlying securities,
currencies or futures contracts, its potential loss is unlimited. The Fund
will be required, however, to set aside with its custodian bank liquid assets
in amounts sufficient at all times to satisfy its obligations under options
and futures contracts.     
 
  The successful use of options and futures will usually depend on Loomis
Sayles' ability to forecast stock market, currency or other financial market
 
                                      18
<PAGE>
 
   
movements correctly. The Fund's ability to hedge against adverse changes in
the value of securities held in its portfolio through options and futures also
depends on the degree of correlation between changes in the value of futures
or options positions and changes in the values of the portfolio securities.
The successful use of futures and exchange traded options also depends on the
availability of a liquid secondary market to enable the Fund to close its
positions on a timely basis. There can be no assurance that such a market will
exist at any particular time. In the case of options that are not traded on an
exchange ("over-the-counter" options), the Fund is at risk that the other
party to the transaction will default on its obligations, or will not permit
the Fund to terminate the transaction before its scheduled maturity. As a
result of these characteristics, the Fund will treat most over-the-counter
options (and the assets it segregates to cover its obligations thereunder) as
illiquid.     
 
  The options and futures markets of foreign countries are small compared to
those of the United States and consequently are characterized in most cases by
less liquidity than are the U.S. markets. In addition, foreign markets may be
subject to less detailed reporting requirements and regulatory controls than
U.S. markets. Furthermore, investments in options in foreign markets are
subject to many of the same risks as other foreign investments. See "Foreign
Securities" above.
 
REPURCHASE AGREEMENTS
 
  Each Fund may invest in repurchase agreements. In repurchase agreements, a
Fund buys securities from a seller, usually a bank or brokerage firm, with the
understanding that the seller will repurchase the securities at a higher price
at a later date. Such transactions afford an opportunity for a Fund to earn a
return on available cash at minimal market risk, although the Fund may be
subject to various delays and risks of loss if the seller is unable to meet
its obligations to repurchase.
       
YEAR 2000
 
  Many computer software systems in use today cannot properly process date-
related information from and after January 1, 2000. Should any of the computer
systems employed by the Funds' major service providers fail to process this
type of information properly, that could have a negative impact on the Funds'
operations and the services that are provided to the Funds' shareholders.
Loomis Sayles and the Distributor have each advised the Funds that they are
reviewing all of their computer systems with the goal of modifying or
replacing such systems prior to January 1, 2000, to the extent necessary to
foreclose any such negative impact. In addition, Loomis Sayles has been
advised by the Funds' custodian that it is also in the process of reviewing
its systems with the same goal. As of the date of this prospectus, the Funds
and Loomis
 
                                      19
<PAGE>
 
Sayles have no reason to believe that these goals will not be achieved.
Similarly, the values of certain of the portfolio securities held by the Funds
may be adversely affected by the inability of the securities' issuers or of
third parties to process this type of information properly.
 
                         THE FUNDS' INVESTMENT ADVISER
 
  The Funds' investment adviser is Loomis Sayles, One Financial Center,
Boston, Massachusetts 02111. Founded in 1926, Loomis Sayles is one of the
country's oldest and largest investment firms. The general partner of Loomis
Sayles is a special purpose corporation that is an indirect wholly-owned
subsidiary of Nvest Companies, L.P. ("Nvest Companies"). Nvest Companies'
managing general partner, Nvest Corporation, is a direct wholly-owned
subsidiary of Metropolitan Life Insurance Company ("Met Life"), a mutual life
insurance company. Nvest Companies' advising general partner, Nvest, L.P., is
a publicly traded company listed on the New York Stock Exchange. Nvest
Corporation is the sole general partner of Nvest L.P.
 
  In addition to selecting and reviewing the Funds' investments, Loomis Sayles
provides executive and other personnel for the management of the Funds. The
Funds' board of trustees supervises Loomis Sayles' conduct of the affairs of
the Funds.
          
  As of October 31, 1998, Daniel J. Fuss, Rosemary B. Fuss, and Charles Schwab
& Co. Inc. owned 20%, 7%, and 38% of the High Yield Fund. As of October 31,
1998, Charles Schwab & Co. Inc. owned 68% of the U.S. Government Securities
Fund. Shareholders holding more than 25% of a Fund's shares may be deemed to
control the relevant Fund.     
   
  Daniel J. Fuss, President of the Trust and Executive Vice President of
Loomis Sayles, has served as the portfolio manager of the High Yield Fund
since its commencement of investment operations in 1996. Kathleen C. Gaffney,
Vice President of the Trust and Loomis Sayles, has served as associate
portfolio manager of the High Yield Fund since its commencement of investment
operations in 1996. Kent P. Newmark, Vice President of the Trust and of Loomis
Sayles, has served as the portfolio manager of the U.S. Government Securities
Fund since its commencement of investment operations in 1991. Each of the
foregoing has been employed by Loomis Sayles for at least five years.     
 
                                 FUND EXPENSES
 
  Each Fund pays Loomis Sayles a monthly investment advisory fee at the
following annual percentage rates of the Fund's average daily net assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                     RATE
   ----                                                                     ----
   <S>                                                                      <C>
   High Yield.............................................................. .60%
   U.S. Government Securities.............................................. .30%
</TABLE>    
 
                                      20
<PAGE>
 
  In addition to the investment advisory fee, each Fund pays all expenses not
expressly assumed by Loomis Sayles, including taxes, brokerage commissions,
fees and expenses of the registering or qualifying the Fund's shares under
federal and state securities laws, fees of the Fund's custodian, transfer
agent, independent accountants and legal counsel, expenses of shareholders'
and trustees' meetings, expenses of preparing, printing and mailing
prospectuses to shareholders and fees of trustees who are not directors,
officers or employees of Loomis Sayles or its affiliated companies.
 
  Loomis Sayles has voluntarily agreed, for an indefinite period, to reduce
its advisory fees and/or bear other Fund expenses to the extent necessary to
limit Fund total annual operating expenses of the Institutional Class shares
of each Fund to the following annual percentage rate of the Fund's average net
assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                     RATE
   ----                                                                     ----
   <S>                                                                      <C>
   High Yield.............................................................. .75%
   U.S. Government Securities.............................................. .50%
</TABLE>    
 
  Loomis Sayles may change or terminate these voluntary arrangements at any
time, but the Funds' Prospectus would be supplemented to describe the change.
 
  Loomis Sayles may pay certain broker-dealers and financial intermediaries
whose customers own shares of the Funds a continuing fee in an amount of up to
 .25% annually of the value of Fund shares held for those customers' accounts.
These fees are paid by Loomis Sayles out of its own assets and are not
assessed against the Funds.
   
  Purchases of the Institutional Class of shares of each Fund and the Retail
Class of shares of the High Yield Fund are subject to approval by Loomis
Sayles.     
 
                            PORTFOLIO TRANSACTIONS
 
  Portfolio turnover considerations will not limit Loomis Sayles' investment
discretion in managing the Funds' assets. The Funds anticipate that their
portfolio turnover rates will vary significantly from time to time depending
on the volatility of economic and market conditions. High portfolio turnover
may involve higher costs and higher levels of taxable gains.
 
                            HOW TO PURCHASE SHARES
 
  An investor may make an initial purchase of shares of any Fund by submitting
a completed application form and payment to:
 
      Boston Financial Data Services
      P.O. Box 8314
      Boston, Massachusetts 02266-8314
      Attn: Loomis Sayles Funds
 
                                      21
<PAGE>
 
   
  The minimum initial investment for the Institutional Class of shares of each
Fund and the Retail Class of shares of the High Yield Fund is $25,000. This
minimum initial investment for Retail Class shares does not apply to purchases
through certain financial intermediaries, including, but not limited to,
certain financial advisers, broker dealers, 401(k) alliances, wrap programs,
"no transaction fee" programs, bank trust departments, financial consultants
and insurance companies. The minimum investment for Institutional Class shares
and Retail Class shares may be waived in whole or in part by Loomis Sayles in
its sole discretion. Subsequent investments in either class of shares must be
at least $50.     
   
  Shares of each Fund may be purchased by (i) cash, (ii) exchanging
Institutional Class shares of any fund that is a series of the trust (for
Institutional Class shares of each Fund) and Retail Class shares of any other
Fund that is a series of the trust (for Retail Class shares of the High Yield
Fund), provided the value of the shares exchanged meets the investment minimum
of the Class of shares of the Fund into which the exchange is made and Loomis
Sayles has approved the exchange of the shares, (iii) exchanging securities on
deposit with a custodian acceptable to Loomis Sayles or (iv) a combination of
such securities and cash. Loomis Sayles will not approve the acceptance of
securities in exchange for shares of any Fund unless (1) Loomis Sayles, in its
sole discretion, believes the securities are appropriate investments for the
Fund; (2) the investor represents and agrees that all securities offered to
the Fund can be resold by the Fund without restriction under the Securities
Act of 1933, as amended (the "Securities Act") or otherwise; and (3) the
securities are eligible to be acquired under the Fund's investment policies
and restrictions. No investor owning 5% or more of a Fund's shares may
purchase additional shares of that Fund by exchange of securities.     
   
  In all cases Loomis Sayles reserves the right to reject any securities that
are proposed for exchange. Securities accepted by Loomis Sayles in exchange
for Fund shares will be valued in the same manner as the Fund's assets as
described below as of the time of the Fund's next determination of net asset
value after such acceptance. All dividends and subscription or other rights
which are reflected in the market price of accepted securities at the time of
valuation become the property of the Fund and must be delivered to the Fund
upon receipt by the investor from the issuer. A gain or loss for federal
income tax purposes would be realized upon the exchange by an investor that is
subject to federal income taxation, depending upon the investor's basis in the
securities tendered. An investor who wishes to purchase shares by exchanging
securities should obtain instructions by calling 800-633-3330.     
 
                                      22
<PAGE>
 
  All purchases made by check should be in U.S. dollars and made payable to
State Street Bank and Trust Company. Third party checks will not be accepted.
When purchases are made by check or periodic account investment, redemption
will not be allowed until the investment being redeemed has been in the
account for 15 calendar days.
 
  Upon acceptance of an investor's order, BFDS opens an account, applies the
payment to the purchase of full and fractional Fund shares and mails a
statement of the account confirming the transaction.
 
  After an account has been established, an investor may send subsequent
investments at any time directly to BFDS at the above address. The remittance
must be accompanied by either the account identification slip detached from a
statement of account or a note containing sufficient information to identify
the account, i.e., the Fund name and the investor's account number or name and
social security number.
   
  Subsequent investments can also be made by federal funds wire. Investors
should instruct their banks to wire federal funds to State Street Bank and
Trust Company, ABA #011000028. The text of the wire should read as follows:
"$    amount, STATE STREET BOS ATTN Mutual Funds. Credit Fund (Fund Name and
Class, Institutional or Retail), DDA #9904-622-9, Account Name, Account
Number." A bank may charge a fee for transmitting funds by wire.     
 
  Each Fund and the Distributor reserve the right to reject any purchase
order, including orders in connection with exchanges, for any reason which the
Fund or the Distributor in its sole discretion deems appropriate. Although the
Funds do not presently anticipate that they will do so, each Fund reserves the
right to suspend or change the terms of the offering of its shares.
 
  The price an investor pays will be the per share net asset value next
calculated after a proper investment order is received by the Trust's transfer
or other agent or subagent. Shares of each Fund are sold with no sales charge.
The net asset value of each Fund's shares is calculated once daily as of the
close of regular trading on the New York Stock Exchange on each day the
Exchange is open for trading, by dividing the Fund's net assets by the number
of shares outstanding. Portfolio securities are valued at their market value
as more fully described in the Statement of Additional Information.
 
  The Distributor may accept telephone orders from broker-dealers who have
been previously approved by the Distributor. It is the responsibility of such
broker-dealers to promptly forward purchase or redemption orders to the
Distributor. Although there is no sales charge imposed by the Fund or the
Distributor, broker-dealers may charge the investor a transaction-based fee or
 
                                      23
<PAGE>
 
other fee for their services at either the time of purchase or the time of
redemption. Such charges may vary among broker-dealers but in all cases will
be retained by the broker-dealer and not remitted to the Fund.
       
       
       
                             SHAREHOLDER SERVICES
 
  The Funds offer the following shareholder services, which are more fully
described in the Statement of Additional Information. Explanations and forms
are available from BFDS. Telephone redemption and exchange privileges will be
established automatically when an investor opens an account unless an investor
elects on the application to decline the privileges. Other privileges must be
specifically elected. A signature guarantee will be required to establish a
privilege after an account is opened.
   
  FREE EXCHANGE PRIVILEGE. The Institutional Class shares and Retail Class
Shares of any Fund may be exchanged for Institutional Class shares or Retail
Class shares, respectively, of any fund that is a series of Loomis Sayles
Funds and that offers Institutional Class shares or Retail Class shares,
respectively, or for shares of certain money market funds advised by New
England Funds Management, L.P., an affiliate of Loomis Sayles, provided the
value of the shares exchanged meets the investment minimum of the Class of
shares of that fund. Exchanges may be made by written instructions or by
telephone, unless an investor elected on the application to decline telephone
exchange privileges. The exchange privilege should not be viewed as a means
for taking advantage of short-term swings in the market, and the Funds reserve
the right to terminate or limit the privilege of any shareholder who makes
more than four exchanges in any calendar year. The Funds may terminate or
change the terms of the exchange privilege at any time, upon 60 days' notice
to shareholders. Exchanges of shares of the High Yield Fund purchased within
one year before such exchanges will be subject to a redemption fee of 2.00% of
the amount exchanged. For purposes of determining whether a redemption fee is
payable with respect to shares of the High Yield Fund purchased by exchange of
shares of another Fund, the one-year period shall be deemed to begin on the
date of such purchase by exchange. An exchange is a taxable event for federal
income tax purposes in which a gain or loss would be realized by an investor
that is subject to federal income taxation.     
 
  RETIREMENT PLANS. The Funds' shares may be purchased by all types of tax-
deferred retirement plans. Loomis Sayles makes available retirement plan forms
for IRAs.
       
                                      24
<PAGE>
 
       
                             HOW TO REDEEM SHARES
   
  An investor can redeem shares by sending a written request to Boston
Financial Data Services, Inc., P.O. Box 8314, Boston, Massachusetts 02266.
Proceeds from a written request may be sent to the investor in the form of a
check. As described below, an investor may also redeem shares by calling BFDS
at 800-626-9390. Proceeds resulting from a written or telephone redemption
request can be wired to an investor's bank account or sent by check in the
name of the registered owners to their record address.     
   
  The written request must include the name of the Fund, the account number,
the exact name(s) in which the shares are registered, and the number of shares
or the dollar amount to be redeemed. All owners of the shares must sign the
request in the exact names in which the shares are registered (this appears on
an investor's confirmation statement) and should indicate any special capacity
in which they are signing (such as trustee or custodian or on behalf of a
partnership, corporation or other entity). Investors requesting that
redemption proceeds be wired to their bank accounts must provide specific wire
instructions.     
 
  If (1) an investor is redeeming shares worth more than $50,000, (2) an
investor is requesting that the proceeds check be made out to someone other
than the registered owners or be sent to an address other than the record
address, (3) the account registration has changed within the last 30 days or
(4) an investor is instructing us to wire the proceeds to a bank account not
designated on the application, the investor must have his or her signature
guaranteed by an eligible guarantor. This requirement may be waived by Loomis
Sayles in its sole discretion. Eligible guarantors include commercial banks,
trust companies, savings associations, credit unions and brokerage firms that
are members of domestic securities exchanges. Before submitting the redemption
request, an investor should verify with the guarantor institution that it is
an eligible guarantor. Signature guarantees by notaries public are not
acceptable.
 
  When an investor telephones a redemption request, the proceeds are wired to
the bank account previously chosen by the investor. A wire fee (currently $5)
will be deducted from the proceeds. A telephonic redemption request must be
received by BFDS prior to the close of regular trading on the New York Stock
Exchange. If an investor telephones a request to BFDS after the Exchange
closes or on a day when the Exchange is not open for business, BFDS cannot
accept the request and a new one will be necessary.
 
                                      25
<PAGE>
 
  If an investor decides to change the bank account to which proceeds are to
be wired, the investor must send in this change in writing with a signature
guarantee. Telephonic redemptions may only be made if the investor's bank is a
member of the Federal Reserve System or has a correspondent bank that is a
member of the System. Unless an investor indicates otherwise on the account
application, BFDS will be authorized to act upon redemption and exchange
instructions received by telephone from the investor or any person claiming to
act as the investor's representative who can provide BFDS with the investor's
account registration and address as it appears on the records of State Street
Bank. BFDS will employ these or other reasonable procedures to confirm that
instructions communicated by telephone are genuine; the Fund, State Street
Bank, BFDS, the Distributor and Loomis Sayles will not be liable for any
losses due to unauthorized or fraudulent instructions if these or other
reasonable procedures are followed. For information, consult BFDS. In times of
heavy market activity, an investor who encounters difficulty in placing a
redemption or exchange order by telephone may wish to place the order by mail
as described above.
 
  The redemption price will be the net asset value per share next determined
after the redemption request and any necessary special documentation are
received by BFDS in proper form, less, in the case of the High Yield Fund, a
redemption fee of 2.00% of the amount redeemed with respect to shares of that
Fund purchased within one (1) year of such redemption. Loomis Sayles, in its
discretion, may waive the 2.00% redemption fee with respect to shares of the
High Yield Fund.
 
  Proceeds resulting from a written redemption request will normally be mailed
to an investor within seven days after receipt of the investor's request in
good order. Telephonic redemption proceeds will normally be wired to an
investor's bank on the first business day following receipt of a proper
redemption request. If an investor purchased shares by check and the check was
deposited less than 15 days prior to the redemption request, the Fund may
withhold redemption proceeds until the check has cleared.
 
  The Fund may suspend the right of redemption and may postpone payment for
more than seven days when the New York Stock Exchange is closed for other than
weekends or holidays, or if permitted by the rules of the SEC when trading on
the Exchange is restricted or during an emergency which makes it impracticable
for the Fund to dispose of its securities or to determine fairly the value of
its net assets, or during any other period permitted by the SEC for the
protection of investors.
 
                                      26
<PAGE>
 
                    CALCULATION OF PERFORMANCE INFORMATION
 
  The Funds' investment performance may from time to time be included in
advertisements about the Funds. "Yield" for each class of shares is calculated
by dividing the annualized net investment income per share during a recent 30-
day period by the maximum public offering price per share of the class on the
last day of that period.
 
  For purposes of calculating yield, net investment income is calculated in
accordance with SEC regulations and may differ from net investment income as
determined for financial reporting purposes. SEC regulations require that net
investment income be calculated on a "yield-to-maturity" basis, which has the
effect of amortizing any premiums or discounts in the current market value of
fixed income securities. The current dividend rate is based on net investment
income as determined for tax purposes, which may not reflect amortization in
the same manner.
 
  Yield is based on the price of the shares but does not reflect any
redemption fee in the case of the High Yield Fund.
 
  "Total return" for the one-, five- and ten-year periods (or for the life of
a class, if shorter) through the most recent calendar quarter represents the
average annual compounded rate of return on an investment of $1,000 in a Fund.
Total return may also be presented for other periods.
 
                DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES
   
  The High Yield and U.S. Government Securities Funds declare and pay
dividends quarterly. Each Fund also distributes all of its net capital gains
realized from the sale of portfolio securities. Any capital gain distributions
are normally made annually, but may, to the extent permitted by law, be made
more frequently as deemed advisable by the trustees of the Trust. The Trust's
trustees may change the frequency with which the Funds declare or pay
dividends.     
   
  Dividends and capital gain distributions will automatically be reinvested in
additional shares of the same Fund unless an investor has elected to receive
cash.     
 
  Each Fund intends to qualify as a regulated investment company under the
Internal Revenue Code of 1986, as amended. As such, so long as a Fund
distributes substantially all its net investment income and net capital gains
to its shareholders, the Fund itself does not pay any federal income tax to
the extent such income and gains are so distributed.
   
  An investor's income dividends and short-term capital gain distributions are
taxable as ordinary income whether distributed in cash or additional shares.
    
                                      27
<PAGE>
 
   
Distributions designated by a Fund as deriving from net gains on securities
held for more than one year will be taxable as such (generally at a 20% rate
for noncorporate Shareholders) whether distributed in cash or additional
shares and regardless of how long an investor has owned shares of the Fund.
       
  A dividend or distribution made shortly after the purchase of shares of a
Fund by a shareholder, although in effect a return of capital to that
particular shareholder, would be taxable to him or her as described above. If
a shareholder held shares six months or less and during that period received a
distribution of net capital gains, any loss realized on the sale of such
shares during such six-month period would be a long-term capital loss to the
extent of such distribution.     
   
  Each Fund is required to withhold 31% of any redemption proceeds (including
the value of shares exchanged) and all income dividends and capital gain
distributions it pays (1) if an investor does not provide a correct, certified
taxpayer identification number, (2) if the Fund is notified that an investor
has underreported income in the past, or (3) if an investor fails to certify
to the Fund that he or she is not subject to such withholding.     
 
  Dividends derived from interest on U.S. Government Securities may be exempt
from state and local taxes.
 
  State Street Bank will send investors and the IRS an annual statement
detailing federal tax information, including information about dividends and
distributions paid during the preceding year. An investor should keep this
statement as a permanent record. A fee may be charged for any duplicate
information requested.
       
NOTE: The foregoing summarizes certain tax consequences of investing in the
         Funds. Before investing, an investor should consult his or her own
         tax adviser for more information concerning the federal, foreign,
         state and local tax consequences of investing in, redeeming or
         exchanging Fund shares.
 
                                      28
<PAGE>
 
                                                                     APPENDIX A
 
                    DESCRIPTION OF BOND RATINGS ASSIGNED BY
                             STANDARD & POOR'S AND
                        MOODY'S INVESTORS SERVICE, INC.
 
STANDARD & POOR'S
 
                                      AAA
 
  This is the highest rating assigned by Standard & Poor's to a debt
obligation and indicates an extremely strong capacity to pay interest and
repay principal.
 
                                      AA
 
  Bonds rated AA also qualify as high quality debt obligations. Capacity to
pay interest and repay principal is very strong, and in the majority of
instances they differ from AAA issues only in small degree.
 
                                       A
 
  Bonds rated A have a strong capacity to pay interest and repay principal,
although they are somewhat more susceptible to the adverse effects of changes
in circumstances and economic conditions than obligations in higher rated
categories.
 
                                      BBB
 
  Bonds rated BBB are regarded as having an adequate capacity to pay interest
and repay principal. Whereas they normally exhibit adequate protection
parameters, adverse economic conditions or changing circumstances are more
likely to lead to a weakened capacity to repay principal and pay interest for
bonds in this category than for bonds in higher rated categories.
 
                                BB, B, CCC, CC
 
  Bonds rated BB, B, CCC and CC are regarded, on balance, as predominantly
speculative with respect to capacity to pay interest and repay principal in
accordance with the terms of the obligation. BB indicates the lowest degree of
speculation and CC the highest degree of speculation. While such bonds will
likely have some quality and protective characteristics, these are outweighed
by large uncertainties or major risk exposures to adverse conditions.
 
                                      29
<PAGE>
 
                                       C
 
  The rating C is reserved for income bonds on which no interest is being
paid.
 
                                       D
 
  Bonds rated D are in default, and payment of interest and/or repayment of
principal is in arrears.
 
                                       R
 
  This symbol is attached to the ratings of instruments with significant
noncredit risks such as risks to principal or volatility of expected returns.
 
  Plus (+) or Minus (-): The ratings from "AA" to "B" may be modified by the
addition of a plus or minus sign to show relative standing within the major
rating categories.
 
MOODY'S INVESTORS SERVICE, INC.
 
                                      AAA
 
  Bonds that are rated Aaa are judged to be of the best quality. They carry
the smallest degree of investment risk and are generally referred to as "gilt
edged." Interest payments are protected by a large, or by an exceptionally
stable, margin, and principal is secure. While the various protective elements
are likely to change, such changes as can be visualized are most unlikely to
impair the fundamentally strong position of such issues.
 
                                      AA
 
  Bonds that are rated Aa are judged to be high quality by all standards.
Together with the Aaa group they comprise what are generally known as high
grade bonds. They are rated lower than the best bonds because margins of
protection may not be as large as in Aaa securities or fluctuation of
protective elements may be of greater amplitude or there may be other elements
present that make the long-term risks appear somewhat larger than in Aaa
securities.
 
                                       A
 
  Bonds that are rated A possess many favorable investment attributes and are
to be considered as upper medium grade obligations. Factors giving security to
principal and interest are considered adequate, but elements may be present
that suggest a susceptibility to impairment sometime in the future.
 
 
                                      30
<PAGE>
 
                                      BAA
 
  Bonds that are rated Baa are considered as medium grade obligations; i.e.,
they are neither highly protected nor poorly secured. Interest payments and
principal security appear adequate for the present, but certain protective
elements may be lacking or may be characteristically unreliable over any great
length of time. Such bonds lack outstanding investment characteristics and, in
fact, have speculative characteristics as well.
 
                                      BA
 
  Bonds which are rated Ba are judged to have speculative elements; their
future cannot be considered as well assured. Often, the protection of interest
and principal payments may be very moderate, and thereby not well safeguarded
during both good and bad times over the future. Uncertainty of position
characterizes bonds in this class.
 
                                       B
 
  Bonds which are rated B generally lack characteristics of the desirable
investment. Assurance of interest and principal payments or of maintenance of
other terms of the contract over any long period of time may be small.
 
                                      CAA
 
  Bonds which are rated Caa are of poor standing. Such issues may be in
default or there may be present elements of danger with respect to principal
or interest.
 
                                      CA
 
  Bonds which are rated Ca represent obligations which are speculative in a
high degree. Such issues are often in default or have other marked
shortcomings.
 
                                       C
 
  Bonds which are rated C are the lowest rated class of bonds, and issues so
rated can be regarded as having extremely poor prospects of ever attaining any
real investment standing.
 
                                      31
<PAGE>
 
  Should no rating be assigned by Moody's, the reason may be one of the
following:
 
 1. An application for rating was not received or accepted.
 
 2. The issue or issuer belongs to a group of securities that are not rated
    as a matter of policy.
 
 3. There is a lack of essential data pertaining to the issue or issuer.
 
 4. The issue was privately placed in which case the rating is not published
    in Moody's publications.
 
  Suspension or withdrawal may occur if new and material circumstances arise,
the effects of which preclude satisfactory analysis; if there is no longer
available reasonable up-to-date data to permit a judgment to be formed; if a
bond is called for redemption; or for other reasons.
 
Note:  Those bonds in the Aa, A, Baa, Ba and B groups which Moody's believes
       possess the strongest investment attributes are designated by the
       symbols Aa1, A1, Baa1, Ba1 and B1.
 
 
                                      32
<PAGE>
 
INVESTMENT ADVISER 
Loomis, Sayles & Company, L.P. 
One Financial Center 
Boston, Massachusetts 02111
 
DISTRIBUTOR 
Loomis Sayles Distributors, L.P. 
One Financial Center 
Boston, Massachusetts 02111
 
TRANSFER AND DIVIDEND PAYING AGENT 
AND CUSTODIAN OF ASSETS 
State Street Bank and Trust Company 
Boston, Massachusetts 02102
 
SHAREHOLDER SERVICING AGENT FOR 
STATE STREET BANK AND TRUST COMPANY 
Boston Financial Data Services, Inc. 
P.O. Box 8314
Boston, Massachusetts 02266
 
LEGAL COUNSEL 
Ropes & Gray 
One International Place 
Boston, Massachusetts 02110

INDEPENDENT ACCOUNTANTS
   
PricewaterhouseCoopers LLP      
One Post Office Square 
Boston, Massachusetts 02109 
<PAGE>

[LOGO OF LOOMIS SAYLES FUNDS APPEARS HERE]


 
 ONE FINANCIAL CENTER . BOSTON, MASSACHUSETTS 02111 . (800) 633-3330
 
THE LOOMIS SAYLES FUNDS
   
 LOOMIS SAYLES GROWTH FUND     
   
 INSTITUTIONAL CLASS     
   
 RETAIL CLASS     
<PAGE>
 
PROSPECTUS                                                    
                                                           JANUARY 1, 1999     
   
LOOMIS SAYLES GROWTH FUND     
   
  Loomis Sayles Growth Fund (the "Fund") is a series of Loomis Sayles Funds
(the "Trust"), a registered open-end management investment company, and is a
no-load mutual fund. Loomis, Sayles & Company, L.P. ("Loomis Sayles") is the
investment adviser of the Fund.     
   
  The Fund offers two classes of shares: an Institutional Class, which
generally has a higher minimum investment and bears lower expenses, and a
Retail Class, which has a lower investment minimum and bears higher expenses.
Each Class of the Fund has a common investment objective and investment
portfolio. The performance of one class of shares may be different from the
performance of the other Class of shares because of different sales charges
and class expenses. This Prospectus concisely describes the information that
an investor should know before investing in either the Institutional Class
shares or Retail Class shares of the Fund. Please read it carefully and keep
it for future reference. A Statement of Additional Information (SAI) dated
January 1, 1999, as revised from time to time, is available free of charge;
write to Loomis Sayles Distributors, L.P. (the "Distributor"), One Financial
Center, Boston, Massachusetts 02111 or telephone 800-633-3330. The SAI, which
contains more detailed information about the Fund, has been filed with the
Securities and Exchange Commission (the "SEC") and is available along with
other related materials on the SEC's Internet Website (http://www.sec.gov).
The SAI is incorporated herein by reference (legally forms a part of the
Prospectus).     
 
  For information about:                    For all other information about
   .Establishing an account                 the Funds:
   .Account procedures and status           CALL 800-633-3330
   .Exchanges
   .Shareholder services
  CALL 800-626-9390
 
  THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS
A CRIMINAL OFFENSE.
 
 
 
                                       1
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>   
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
SUMMARY OF EXPENSES.......................................................   3
FINANCIAL HIGHLIGHTS......................................................   4
THE TRUST.................................................................   6
INVESTMENT OBJECTIVES AND POLICIES........................................   6
MORE INFORMATION ABOUT THE FUND'S INVESTMENTS AND RISK CONSIDERATIONS.....   6
THE FUND'S INVESTMENT ADVISER.............................................  10
FUND EXPENSES.............................................................  10
PORTFOLIO TRANSACTIONS....................................................  11
HOW TO PURCHASE SHARES....................................................  11
SHAREHOLDER SERVICES......................................................  14
HOW TO REDEEM SHARES......................................................  15
CALCULATION OF PERFORMANCE INFORMATION....................................  16
DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES...........................  17
APPENDIX A
</TABLE>    
       
                                       2
<PAGE>
 
                              SUMMARY OF EXPENSES
       
   
  The following information is provided as an aid in understanding the various
expenses that an investor in the Fund will bear indirectly. The information is
based on expenses for the Fund's most recent fiscal year. The information
below should not be considered a representation of past or future expenses, as
actual expenses may be greater or less than those shown. Also, the 5% annual
return assumed in the Example should not be considered a representation of
investment performance, as actual performance will vary.     
 
<TABLE>   
<CAPTION>
                                                      INSTITUTIONAL   RETAIL
                                                          CLASS       CLASS
                                                      -------------   ------
 <S>                                                  <C>             <C>
 Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on Purchases (as % of
  offering price)...................................      none         none
 Maximum Sales Load Imposed on Reinvested Dividends
  (as % of offering price)..........................      none         none
 Maximum Deferred Sales Load (as % of original
  purchase price or redemption proceeds)............      none         none
 Redemption Fees/1.............................../..      none         none
 Exchange Fees......................................      none         none
 Annual Fund Operating Expenses (as a percentage of
  average net assets):
 Management Fees....................................       .50%         .50%
 12b-1 Fees.........................................      none          .25%
 Other Operating Expenses (after expense
  reimbursements)...................................       .35%(/2/)    .35%(/2/)
 Total Fund Operating Expenses (after expense
  reimbursements)...................................       .85%(/2/)   1.10%(/2/)
 Example:
 An investor would pay the following expenses on a
  $1,000 investment assuming a 5% annual return
  (with or without a redemption at the end of each
  time period):
 One Year...........................................      $  9         $ 11
 Three Years........................................      $ 27         $ 35
 Five Years.........................................      $ 47         $ 61
 Ten Years..........................................      $105         $134
</TABLE>    
- -----------
/1/A $5 charge applies to any wire transfer of redemption proceeds.
   
/2/Loomis Sayles has voluntarily agreed for an indefinite period, to limit the
  Total Operating Expenses of the Fund's Institutional Class of shares and
  Retail Class of shares to 0.85% and 1.10%, respectively. Without this
  agreement, Other Operating Expenses and Total Operating Expenses would have
  been 0.52% and 1.02% for the Fund's Institutional Class of shares and 4.24%
  and 4.74% for the Retail Class of shares.     
 
                                       3
<PAGE>
 
                             FINANCIAL HIGHLIGHTS
                            
                         (FOR A SHARE OF THE FUND     
                 OUTSTANDING THROUGHOUT THE INDICATED PERIODS)
   
  The financial highlights table that follows has been audited by
PricewaterhouseCoopers LLP, independent accountants. The following information
should be read in conjunction with the financial highlights, financial
statements and the notes thereto contained in the Fund's 1998 Annual Report,
which is incorporated by reference in this Prospectus and the Statement of
Additional Information.     
 
<TABLE>   
<CAPTION>
                                             GROWTH FUND--INSTITUTIONAL CLASS
                          -----------------------------------------------------------------------------
                           NINE MONTHS                                                         MAY 16**
                              ENDED                    YEAR ENDED DEC. 31,                        TO
                          SEPTEMBER 30*, ----------------------------------------------------  DEC. 31,
                               1998       1997     1996     1995     1994     1993     1992      1991
                          -------------- -------  -------  -------  -------  -------  -------  --------
<S>                       <C>            <C>      <C>      <C>      <C>      <C>      <C>      <C>
Net asset value,
 beginning of period....     $ 12.63      $13.44  $ 15.27  $ 12.50  $ 13.02  $ 12.46  $ 12.01  $ 10.00
                             -------     -------  -------  -------  -------  -------  -------  -------
Income from investment
 operations--
 Net investment income
  (loss)................       (0.03)      (0.04)   (0.07)    0.00    (0.02)    0.00    (0.04)    0.00
 Net realized and
  unrealized gain (loss)
  on investments........       (0.95)       3.17     3.08     3.86    (0.45)    1.16     0.49     2.45
                             -------     -------  -------  -------  -------  -------  -------  -------
 Total from investment
  operations............       (0.98)       3.13     3.01     3.86    (0.47)    1.16     0.45     2.45
                             -------     -------  -------  -------  -------  -------  -------  -------
Less distributions--
 Distributions from
  capital...............        0.00        0.00     0.00     0.00    (0.01)    0.00     0.00     0.00
 Distributions from net
  realized capital
  gains.................        0.00       (3.94)   (4.84)   (1.09)   (0.04)   (0.60)    0.00    (0.44)
                             -------     -------  -------  -------  -------  -------  -------  -------
 Total distributions....        0.00       (3.94)   (4.84)   (1.09)   (0.05)   (0.60)    0.00    (0.44)
                             -------     -------  -------  -------  -------  -------  -------  -------
Net asset value, end of
 period.................     $ 11.65      $12.63  $ 13.44  $ 15.27  $ 12.50  $ 13.02  $ 12.46  $ 12.01
                             =======     =======  =======  =======  =======  =======  =======  =======
Total return (%)***.....        (7.8)++     24.5     19.9     30.9     (3.7)     9.3      3.8     24.5
Net assets, end of
 period (000)...........     $24,663     $32,149  $39,497  $45,011  $36,580  $32,385  $24,451  $16,105
Ratio of operating
 expenses to average net
 assets (%)****.........        0.85 +      0.85     1.10     1.08     1.16     1.20     1.50     1.50+
Ratio of net investment
 income to average net
 assets (%).............       (0.32)+     (0.26)   (0.47)   (0.29)   (0.14)   (0.17)   (0.45)    0.01+
Portfolio turnover rate
 (%)....................         118++       116       99       48       46       64       98       69
Without giving effect to
 voluntary expense
 limitations:
 The ratios of operating
  expenses to average
  net assets would have
  been (%)..............        1.02 +      0.98     1.10     1.08     1.16     1.20     1.51     1.66+
 Net investment income
  per share would have
  been..................     $ (0.05)     $(0.05) $ (0.07) $  0.00  $ (0.02) $  0.00  $ (0.04) $ (0.01)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
   + Computed on an annualized basis.     
    
  ++ Periods less than one year are not annualized.     
       


                                       4
<PAGE>
 
<TABLE>   
<CAPTION>
                                                           GROWTH FUND--
                                                           RETAIL CLASS
                                                      -----------------------
                                                       NINE MONTHS   JAN. 2**
                                                          ENDED         TO
                                                      SEPTEMBER 30*, DEC. 31,
                                                           1998        1997
                                                      -------------- --------
 <S>                                                  <C>            <C>
 Net asset value, beginning of period...............      $12.59     $ 13.44
                                                          ------     -------
 Income from investment operations--
 Net investment income (loss).......................       (0.03)      (0.07)
 Net realized and unrealized gain (loss)
 on investments.....................................       (0.97)       3.16
                                                          ------     -------
  Total from investment operations..................       (1.00)       3.09
                                                          ------     -------
 Less distributions--
 Distributions from net realized capital gains......        0.00       (3.94)
                                                          ------     -------
  Total distributions...............................        0.00       (3.94)
                                                          ------     -------
 Net asset value, end of period.....................      $11.59     $ 12.59
                                                          ======     =======
 Total return (%)***................................        (7.9)++     24.2
 Net assets, end of period (000)....................      $  516     $   194
 Ratio of operating expenses to average net
  assets (%)****....................................        1.10 +      1.10+
 Ratio of net investment income to average net
  assets (%)........................................       (0.58)+     (0.42)+
 Portfolio turnover rate (%)........................         118++       116
 Without giving effect to voluntary expense
  limitations:
 The ratios of operating expenses to average net
  assets would have been (%)........................        4.74 +     12.96+
 Net investment income per share would have been....      $(0.19)    $ (2.00)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower, had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
   +  Computed on an annualized basis.     
   
NOTE: Further information about the Fund's performance is contained in the
      Fund's annual report to Shareholders, which may be obtained without
      charge.     
    
  ++  Periods less than one year are not annualized.     
 
                                       5
<PAGE>
 
                                   THE TRUST
 
  The Fund is a series of Loomis Sayles Funds (the "Trust"). The Trust is a
diversified open-end management investment company organized as a
Massachusetts business trust on February 20, 1991. The Trust is authorized to
issue an unlimited number of full and fractional shares of beneficial interest
in multiple series. Shares are freely transferable and entitle shareholders to
receive dividends as determined by the Trust's board of trustees and to cast a
vote for each share held at shareholder meetings. The Trust does not generally
hold shareholder meetings and will do so only when required by law.
Shareholders may call meetings to consider removal of the Trust's trustees.
 
                       INVESTMENT OBJECTIVE AND POLICIES
   
  The Fund's investment objective is long-term growth of capital.     
   
  The Fund seeks to achieve its objective by investing substantially all of
its assets in common stocks or their equivalent. Investments are selected
based on their growth potential; current income is not a consideration. The
Fund may invest in companies with relatively small market capitalizations, as
well as in larger companies. The Fund may invest up to 20% of its total assets
in securities of foreign issuers. The fund may also engage in foreign currency
hedging transactions and Rule 144A securities.     

         

  For temporary defensive purposes, the Fund may invest any portion of its
assets in fixed income securities, cash or any other securities deemed
appropriate by Loomis Sayles. Except for the Fund's investment objective, and
any investment policies that are identified as "fundamental," all of the
investment policies of the Fund may be changed without a vote of Fund
shareholders.
 
                 MORE INFORMATION ABOUT THE FUND'S INVESTMENTS
                            AND RISK CONSIDERATIONS
       
   
COMMON STOCKS AND OTHER EQUITY SECURITIES     
 
  Common stocks and similar equity securities, such as warrants and
convertibles, are volatile and more risky than some other forms of investment.
The value of an investment in a Fund that invests in equity securities may
sometimes decrease. Equity securities of companies with relatively small
market capitalization may be more volatile than the securities of larger, more
established companies and than the broad equity market indexes.
       

WHEN-ISSUED SECURITIES
 
  The Fund may purchase securities on a "when-issued" basis. This means that
the Fund will enter into a commitment to buy the security before the
 
                                       6
<PAGE>
 
security has been issued. The Fund's payment obligation and the interest rate
on the security are determined when the Fund enters into the commitment. The
security is typically delivered to the Fund 15 to 120 days later. No interest
accrues on the security between the time the Fund enters into the commitment
and the time the security is delivered. If the value of the security being
purchased falls between the time the Fund commits to buy it and the payment
date, the Fund may sustain a loss. The risk of this loss is in addition to the
Fund's risk of loss on the securities actually in its portfolio at the time.
In addition, when the Fund buys a security on a when-issued basis, it is
subject to the risk that market rates of interest will increase before the
time the security is delivered, with the result that the yield on the security
delivered to the Fund may be lower than the yield available on other,
comparable securities at the time of delivery. If the Fund has outstanding
obligations to buy when-issued securities, it will maintain liquid assets in a
segregated account at its custodian bank in an amount sufficient to satisfy
these obligations.
       

RULE 144A SECURITIES
 
  The Fund may invest in Rule 144A securities, which are privately offered
securities that can be resold only to certain qualified institutional buyers.
Rule 144A securities are treated as illiquid, unless Loomis Sayles has
determined, under guidelines established by the Trust's trustees, that the
particular issue of Rule 144A securities is liquid.
 
FOREIGN SECURITIES
 
  The Fund may invest in securities of issuers organized or headquartered
outside the United States ("foreign securities"). The Fund may invest any
portion of its assets in securities of Canadian issuers, but will not purchase
foreign securities other than those of Canadian issuers if, as a result, the
Fund's holdings of non-U.S. and non-Canadian securities would exceed 20% of
the Fund's total assets.
 
  Although investing in foreign securities may increase the Fund's
diversification and reduce portfolio volatility, foreign securities may
present risks not associated with investments in comparable securities of U.S.
issuers. There may be less information publicly available about a foreign
corporate or government issuer than about a U.S. issuer, and foreign corporate
issuers are not generally subject to accounting, auditing and financial
reporting standards and practices comparable to those in the United States.
The securities of some foreign issuers are less liquid and at times more
volatile than securities of comparable U.S. issuers. Foreign brokerage
commissions and securities custody costs are often higher than in the United
States. With respect to certain foreign countries, there is a possibility of
governmental expropriation of assets, confiscatory taxation, political or
financial instability and diplomatic
 
                                       7
<PAGE>
 
developments that could affect the value of investments in those countries.
The Fund's receipt of interest on foreign government securities may depend on
the availability of tax or other revenues to satisfy the issuer's obligations.
 
  The Fund's investments in foreign securities may include investments in
countries whose economies or securities markets are not yet highly developed.
Special considerations associated with these investments (in addition to the
considerations regarding foreign investments generally) may include, among
others, greater political uncertainties, an economy's dependence on revenues
from particular commodities or on international aid or development assistance,
currency transfer restrictions, highly limited numbers of potential buyers for
such securities and delays and disruptions in securities settlement
procedures.
 
  Since most foreign securities are denominated in foreign currencies or
traded primarily in securities markets in which settlements are made in
foreign currencies, the value of these investments and the net investment
income available for distribution to shareholders of a Fund investing in these
securities may be affected favorably or unfavorably by changes in currency
exchange rates, exchange control regulations or foreign withholding taxes.
Changes in the value relative to the U.S. dollar of a foreign currency in
which the Fund's holdings are denominated will result in a change in the U.S.
dollar value of the Fund's assets and the Fund's income available for
distribution.
 
  In addition, although part of the Fund's income may be received or realized
in foreign currencies, the Fund will be required to compute and distribute its
income in U.S. dollars. Therefore, if the value of a currency relative to the
U.S. dollar declines after the Fund's income has been earned in that currency,
translated into U.S. dollars and declared as a dividend, but before payment of
the dividend, the Fund could be required to liquidate portfolio securities to
pay the dividend. Similarly, if the value of a currency relative to the U.S.
dollar declines between the time the Fund accrues expenses in U.S. dollars and
the time such expenses are paid, the amount of such currency required to be
converted into U.S. dollars will be greater than the equivalent amount in such
currency of such expenses at the time they were incurred.
 
  In determining whether to invest assets of the Fund in securities of a
particular foreign issuer, Loomis Sayles will consider the likely effects of
foreign taxes on the net yield available to the Fund and its shareholders.
Compliance with foreign tax law may reduce a Fund's net income available for
distribution to shareholders.
 
FOREIGN CURRENCY HEDGING TRANSACTIONS
 
  The Fund may engage in foreign currency exchange transactions to protect the
value of specific portfolio positions or in anticipation of changes in
relative
 
                                       8
<PAGE>
 
values of currencies in which current or future Fund portfolio holdings are
denominated or quoted. For example, to protect against a change in the foreign
currency exchange rate between the date on which the Fund contracts to
purchase or sell a security and the settlement date for the purchase or sale,
or to "lock in" the equivalent of a dividend or interest payment in another
currency, the Fund might purchase or sell a foreign currency on a spot (that
is, cash) basis at the prevailing spot rate. If conditions warrant, the Fund
may also enter into private contracts to purchase or sell foreign currencies
at a future date ("forward contracts"). The Fund might also purchase exchange-
listed and over-the-counter call and put options on foreign currencies. Over-
the-counter currency options are generally less liquid than exchange-listed
options, and will be treated as illiquid assets. The Fund may not be able to
dispose of over-the-counter options readily.
 
  Foreign currency transactions involve costs and may result in losses.
   
REPURCHASE AGREEMENTS     
   
  The Fund may invest in repurchase agreements. In repurchase agreements, a
Fund buys securities from a seller, usually a bank or brokerage firm, with the
understanding that the seller will repurchase the securities at a higher price
at a later date. Such transactions afford an opportunity for a Fund to earn a
return on available cash at minimal market risk, although the Fund may be
subject to various delays and risks of loss if the seller is unable to meet
its obligations to repurchase.     
       
YEAR 2000
 
  Many computer software systems in use today cannot properly process date-
related information from and after January 1, 2000. Should any of the computer
systems employed by the Fund's major service providers fail to process this
type of information properly, that could have a negative impact on the Fund's
operations and the services that are provided to the Fund's shareholders.
Loomis Sayles and the Distributor have each advised the Fund that they are
reviewing all of their computer systems with the goal of modifying or
replacing such systems prior to January 1, 2000, to the extent necessary to
foreclose any such negative impact. In addition, Loomis Sayles has been
advised by the Fund's custodian that it is also in the process of reviewing
its systems with the same goal. As of the date of this prospectus, the Fund
and Loomis Sayles have no reason to believe that these goals will not be
achieved. Similarly, the values of certain of the portfolio securities held by
the Fund may be adversely affected by the inability of the securities' issuers
or of third parties to process this type of information properly.
 
 
                                       9
<PAGE>
 
                         THE FUNDS' INVESTMENT ADVISER
 
  The Fund's investment adviser is Loomis Sayles, One Financial Center,
Boston, Massachusetts 02111. Founded in 1926, Loomis Sayles is one of the
country's oldest and largest investment firms. The general partner of Loomis
Sayles is a special purpose corporation that is an indirect wholly-owned
subsidiary of Nvest Companies, L.P. ("Nvest Companies"). Nvest Companies'
managing general partner, Nvest Corporation, is a direct wholly-owned
subsidiary of Metropolitan Life Insurance Company ("Met Life"), a mutual life
insurance company. Nvest Companies' advising general partner, Nvest, L.P., is
a publicly traded company listed on the New York Stock Exchange. Nvest
Corporation is the sole general partner of Nvest L.P.
 
  In addition to selecting and reviewing the Fund's investments, Loomis Sayles
provides executive and other personnel for the management of the Fund. The
Loomis Sayles Funds' board of trustees supervises Loomis Sayles' conduct of
the affairs of the Fund.

       
   
  As of October 31, 1998, Fiduciary Trust Company owned 12% of the Fund.     
   
  Jerome A. Castellini Vice President of the Trust and of Loomis Sayles, has
served as the portfolio manager of the Growth Fund since its commencement of
investment operations in 1991.     
 
                                 FUND EXPENSES
   
  The Fund pays Loomis Sayles a monthly investment advisory fee of .50% of the
Fund's average daily net assets. In addition to the investment advisory fee,
the Fund pays all expenses not expressly assumed by Loomis Sayles, including
taxes, brokerage commissions, fees and expenses of registering or qualifying
the Fund's shares under federal and state securities laws, fees of the Fund's
custodian, transfer agent, independent accountants and legal counsel, expenses
of shareholders' and trustees' meetings, 12b-1 fees, in the case of the Retail
Class shares, expenses of preparing, printing and mailing prospectuses to
existing shareholders and fees of trustees who are not directors, officers or
employees of Loomis Sayles or its affiliated companies.     
   
  The Fund's Retail Class shares have adopted a Distribution Plan pursuant to
Rule 12b-1 under the Investment Company Act of 1940. Under the Plan, the
Retail Class shares of the Fund pays the Distributor, a subsidiary of Loomis
Sayles, a monthly distribution fee at an annual rate not to exceed 0.25% of
the Fund's average net assets attributable to the Retail Class shares. The
Distributor may pay all or any portion of the distribution fee to securities
dealers or other organizations (including, but not limited to, any affiliate
of the Distributor) as     
 
                                      10
<PAGE>
 
   
commissions, asset-based sales charges or other compensation with respect to
the sale of Retail Class shares of the Fund, or for providing personal
services to investors in Retail Class shares of the Fund and/or the
maintenance of accounts, and may retain all or any portion of the distribution
fee as compensation for the Distributor's services as principal underwriter of
the Retail Class shares of the Fund.     
   
  Loomis Sayles has voluntarily agreed, for an indefinite period, to reduce
its advisory fees and/or bear other Fund expenses to the extent necessary to
limit total annual operating expenses to 0.85% and 1.10% of Institutional
Class shares and Retail Class shares, respectively, of the Fund's average net
assets. Loomis Sayles may change or terminate this voluntary arrangement at
any time, but the Fund's Prospectus would be supplemented to describe the
change.     
   
  Loomis Sayles may pay certain broker-dealers and financial intermediaries
whose customers own shares of the Fund a continuing fee in an amount of up to
 .25% annually of the value of Fund shares held for those customers' accounts.
These fees are paid by Loomis Sayles out of its own assets and are not
assessed against the Fund.     
 
                            PORTFOLIO TRANSACTIONS
 
  Portfolio turnover considerations will not limit Loomis Sayles' investment
discretion in managing the Fund's assets. The Fund anticipates that its
portfolio turnover rates will vary significantly from time to time depending
on the volatility of economic and market conditions. High portfolio turnover
may involve higher costs and higher levels of taxable gains.
 
                            HOW TO PURCHASE SHARES
 
  An investor may make an initial purchase of shares of the Fund by submitting
a completed application form and payment to:
 
      Boston Financial Data Services
      P.O. Box 8314
      Boston, Massachusetts 02266-8314
      Attn: Loomis Sayles Funds
   
  The minimum initial investment for the Institutional Class of shares of the
Fund is $25,000. A $2,500 minimum investment applies to the current and
retired trustees of the Trust, investment advisory clients of Loomis Sayles
(and their directors, officers and employees), and current and retired
employees of Loomis Sayles and the parents, spouses and children of the
foregoing. The     
 
                                      11
<PAGE>
 
   
minimum initial investment for the Retail Class of shares is $25,000. This
minimum initial investment for Retail Class shares does not apply to purchases
through certain financial intermediaries, including, but not limited to,
certain financial advisers, broker dealers, 401(k) alliances, wrap programs,
"no transaction fee" programs, bank trust departments, financial consultants
and insurance companies. The minimum investment for Institutional Class shares
and Retail Class shares may be waived in whole or in part by Loomis Sayles in
its sole discretion. Subsequent investments in either class of shares must be
at least $50.     
   
  Shares of the Fund may be purchased by (i) cash, (ii) exchanging
Institutional Class shares of any other Fund that is a series of the trust
(for Institutional Class shares of the Fund) and Retail Class Shares of any
other fund that is a series of the trust (for Retail Class shares of the
Fund), provided the value of the shares exchanged meets the investment minimum
of the Class of shares of the Fund into which the exchange is made, (iii)
exchanging securities on deposit with a custodian acceptable to Loomis Sayles
or (iv) a combination of such securities and cash. Loomis Sayles will not
approve the acceptance of securities in exchange for shares of the Fund unless
(1) Loomis Sayles, in its sole discretion, believes the securities are
appropriate investments for the Fund; (2) the investor represents and agrees
that all securities offered to the Fund can be resold by the Fund without
restriction under the Securities Act of 1933, as amended (the "Securities
Act") or otherwise; and (3) the securities are eligible to be acquired under
the Fund's investment policies and restrictions. No investor owning 5% or more
of the Fund's shares may purchase additional shares of the Fund by exchange of
securities.     
 
  In all cases Loomis Sayles reserves the right to reject any securities that
are proposed for exchange. Securities accepted by Loomis Sayles in exchange
for Fund shares will be valued in the same manner as the Fund's assets as
described below as of the time of the Fund's next determination of net asset
value after such acceptance. All dividends and subscription or other rights
which are reflected in the market price of accepted securities at the time of
valuation become the property of the Fund and must be delivered to the Fund
upon receipt by the investor from the issuer. A gain or loss for federal
income tax purposes would be realized upon the exchange by an investor that is
subject to federal income taxation, depending upon the investor's basis in the
securities tendered. An investor who wishes to purchase shares by exchanging
securities should obtain instructions by calling 800-633-3330, option 5.
 
  All purchases made by check should be in U.S. dollars and made payable to
State Street Bank and Trust Company. Third party checks will not be accepted.
When purchases are made by check or periodic account investment, redemption
will not be allowed until the investment being redeemed has been in the
account for 15 calendar days.
 
                                      12
<PAGE>
 
  Upon acceptance of an investor's order, BFDS opens an account, applies the
payment to the purchase of full and fractional Fund shares and mails a
statement of the account confirming the transaction.
 
  After an account has been established, an investor may send subsequent
investments at any time directly to BFDS at the above address. The remittance
must be accompanied by either the account identification slip detached from a
statement of account or a note containing sufficient information to identify
the account, i.e., the Fund name and the investor's account number or name and
social security number.
   
  Subsequent investments can also be made by federal funds wire. Investors
should instruct their banks to wire federal funds to State Street Bank and
Trust Company, ABA #011000028. The text of the wire should read as follows:
"$    amount, STATE STREET BOS ATTN Mutual Funds. Credit Fund (Fund Name and
Class, Institutional or Retail), DDA #9904-622-9, Account Name, Account
Number." A bank may charge a fee for transmitting funds by wire.     
 
  The Fund and the Distributor reserve the right to reject any purchase order,
including orders in connection with exchanges, for any reason which the Fund
or the Distributor in its sole discretion deems appropriate. Although the Fund
does not presently anticipate that it will do so, the Fund reserves the right
to suspend or change the terms of the offering of its shares.
 
  The price an investor pays will be the per share net asset value next
calculated after a proper investment order is received by the Trust's transfer
or other agent or subagent. Shares of the Fund are sold with no sales charge.
The net asset value of the Fund's shares is calculated once daily as of the
close of regular trading on the New York Stock Exchange on each day the
Exchange is open for trading, by dividing the Fund's net assets by the number
of shares outstanding. Portfolio securities are valued at their market value
as more fully described in the Statement of Additional Information.
 
  The Distributor may accept telephone orders from broker-dealers who have
been previously approved by the Distributor. It is the responsibility of such
broker-dealers to promptly forward purchase or redemption orders to the
Distributor. Although there is no sales charge imposed by the Fund or the
Distributor, broker-dealers may charge the investor a transaction-based fee or
other fee for their services at either the time of purchase or the time of
redemption. Such charges may vary among broker-dealers but in all cases will
be retained by the broker-dealer and not remitted to the Fund.
       
       
                                      13
<PAGE>
 
                             SHAREHOLDER SERVICES
 
  The Fund offers the following shareholder services, which are more fully
described in the Statement of Additional Information. Explanations and forms
are available from BFDS. Telephone redemption and exchange privileges will be
established automatically when an investor opens an account unless an investor
elects on the application to decline the privileges. Other privileges must be
specifically elected. A signature guarantee will be required to establish a
privilege after an account is opened.
   
  FREE EXCHANGE PRIVILEGE. Institutional Class shares and Retail Class shares
of the Fund may be exchanged for Institutional Class shares or Retail Class
shares, respectively, of any other fund that is a series of Loomis Sayles
Funds and that offers Institutional Class shares or Retail Class shares,
respectively, or for shares of certain money market funds advised by New
England Funds Management, L.P., an affiliate of Loomis Sayles, provided the
value of the shares exchanged meets the investment minimum of the Class of
shares of that Fund and, in the case of Loomis Sayles High Yield Fund and the
Loomis Sayles U.S. Government Securities Fund-Institutional Class, Loomis
Sayles has approved the exchange of shares. Exchanges may be made by written
instructions or by telephone, unless an investor elected on the application to
decline telephone exchange privileges. The exchange privilege should not be
viewed as a means for taking advantage of short-term swings in the market, and
the Fund reserves the right to terminate or limit the privilege of any
shareholder who makes more than four exchanges in any calendar year. The Fund
may terminate or change the terms of the exchange privilege at any time, upon
60 days' notice to shareholders. An exchange is a taxable event for federal
income tax purposes in which a gain or loss would be realized by an investor
that is subject to federal income taxation.     
 
  RETIREMENT PLANS. The Fund's shares may be purchased by all types of tax-
deferred retirement plans. Loomis Sayles makes available retirement plan forms
for IRAs.
 
  SYSTEMATIC WITHDRAWAL PLAN. If the value of an account is at least $25,000,
an investor may have periodic cash withdrawals automatically paid to the
investor or any person designated by the investor.
 
  AUTOMATIC INVESTMENT PLAN. Voluntary monthly investments of at least $50 may
be made automatically by pre-authorized withdrawals from an investor's
checking account.
 
                                      14
<PAGE>
 
                             HOW TO REDEEM SHARES
   
  An investor can redeem shares by sending a written request to Boston
Financial Data Services, Inc., P.O. Box 8314, Boston, Massachusetts 02266. As
described below, an investor may also redeem shares by calling BFDS at
800-626-9390. Proceeds resulting from a written or telephone redemption
request can be wired to an investor's bank account or sent by check in the
name of the registered owners to their record address.     
   
  The written request must include the name of the Fund, the account number,
the exact name(s) in which the shares are registered, and the number of shares
or the dollar amount to be redeemed. All owners of the shares must sign the
request in the exact names in which the shares are registered (this appears on
an investor's confirmation statement) and should indicate any special capacity
in which they are signing (such as trustee or custodian or on behalf of a
partnership, corporation or other entity). Investors requesting that
redemption proceeds be wired to their bank accounts must provide specific wire
instructions.     
 
  If (1) an investor is redeeming shares worth more than $50,000, (2) an
investor is requesting that the proceeds check be made out to someone other
than the registered owners or be sent to an address other than the record
address, (3) the account registration has changed within the last 30 days or
(4) an investor is instructing us to wire the proceeds to a bank account not
designated on the application, the investor must have his or her signature
guaranteed by an eligible guarantor. This requirement may be waived by Loomis
Sayles in its sole discretion. Eligible guarantors include commercial banks,
trust companies, savings associations, credit unions and brokerage firms that
are members of domestic securities exchanges. Before submitting the redemption
request, an investor should verify with the guarantor institution that it is
an eligible guarantor. Signature guarantees by notaries public are not
acceptable.
 
  When an investor telephones a redemption request, the proceeds are wired to
the bank account previously chosen by the investor. A wire fee (currently $5)
will be deducted from the proceeds. A telephonic redemption request must be
received by BFDS prior to the close of regular trading on the New York Stock
Exchange. If an investor telephones a request to BFDS after the Exchange
closes or on a day when the Exchange is not open for business, BFDS cannot
accept the request and a new one will be necessary.
 
  If an investor decides to change the bank account to which proceeds are to
be wired, the investor must send in this change in writing with a signature
guarantee. Telephonic redemptions may only be made if the investor's bank is a
member of the Federal Reserve System or has a correspondent bank that is a
member of the System. Unless an investor indicates otherwise on the account
application, BFDS will be authorized to act upon redemption and exchange
 
                                      15
<PAGE>
 
instructions received by telephone from the investor or any person claiming to
act as the investor's representative who can provide BFDS with the investor's
account registration and address as it appears on the records of State Street
Bank. BFDS will employ these or other reasonable procedures to confirm that
instructions communicated by telephone are genuine; the Fund, State Street
Bank, BFDS, the Distributor and Loomis Sayles will not be liable for any
losses due to unauthorized or fraudulent instructions if these or other
reasonable procedures are followed. For information, consult BFDS. In times of
heavy market activity, an investor who encounters difficulty in placing a
redemption or exchange order by telephone may wish to place the order by mail
as described above.
 
  The redemption price will be the net asset value per share next determined
after the redemption request and any necessary special documentation are
received by BFDS in proper form.
 
  Proceeds resulting from a written redemption request will normally be mailed
to an investor within seven days after receipt of the investor's request in
good order. Telephonic redemption proceeds will normally be wired to an
investor's bank on the first business day following receipt of a proper
redemption request. If an investor purchased shares by check and the check was
deposited less than 15 days prior to the redemption request, the Fund may
withhold redemption proceeds until the check has cleared.
 
  The Fund may suspend the right of redemption and may postpone payment for
more than seven days when the New York Stock Exchange is closed for other than
weekends or holidays, or if permitted by the rules of the SEC when trading on
the Exchange is restricted or during an emergency which makes it impracticable
for the Fund to dispose of its securities or to determine fairly the value of
its net assets, or during any other period permitted by the SEC for the
protection of investors.
 
                    CALCULATION OF PERFORMANCE INFORMATION
       
  "Total return" for the one-, five- and ten-year periods (or for the life of
a class, if shorter) through the most recent calendar quarter represents the
average annual compounded rate of return on an investment of $1,000 in the
Fund. Total return may also be presented for other periods.
 
                                      16
<PAGE>
 
                
             DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES     
   
  The Fund declares and pays net investment income to shareholders as
dividends annually. The Fund also distributes all of its net capital gains
realized from the sale of portfolio securities. Any capital gain distributions
are normally made annually, but may, to the extent permitted by law, be made
more frequently as deemed advisable by the trustees of the Trust. The Trust's
trustees may change the frequency with which the Fund declares or pays
dividends.     
   
  Dividends and capital gain distributions will automatically be reinvested in
additional shares of the Fund unless an investor has elected to receive cash.
The Fund intends to qualify as a regulated investment company under the
Internal Revenue Code of 1986, as amended. As such, so long as the Fund
distributes substantially all its net investment income and net capital gains
to its shareholders, the Fund itself does not pay any federal income tax to
the extent such income and gains are so distributed.     
       
   
  An investor's income dividends and short-term capital gain distributions
(that is, net gains from securities held for not more than a year) are taxable
as ordinary income whether distributed in cash or additional shares.
Distributions designated by all Funds as deriving from net gains on securities
held for more than one year will be taxable as such (generally at a 20% rate
for noncorporate shareholders) whether distributed in cash or additional
shares and regardless of how long an investor has owned shares of the Fund.    
   
  A dividend or distribution made shortly after the purchase of shares of a
Fund by a shareholder, although in effect a return of capital to that
particular shareholder, would be taxable to him or her as described above. If
a shareholder held shares six months or less and during that period received a
distribution of net capital gains, any loss realized on the sale of such
shares during such six-month period would be a long-term capital loss to the
extent of such distribution.     
   
  The Fund is required to withhold 31% of any redemption proceeds (including
the value of shares exchanged) and all income dividends and capital gain
distributions it pays to an investor (1) if an investor does not provide a
correct, certified taxpayer identification number, (2) if the Fund is notified
that an investor has underreported income in the past, or (3) if an investor
fails to certify to the Fund that the investor is not subject to such
withholding.     
   
  Certain designated dividends from the Funds are expected to be eligible for
the dividends-received deduction for corporate shareholders that meet a
holding period requirement.     
   
  State Street Bank will send each investor and the IRS an annual statement
detailing federal tax information, including information about dividends and
    
                                      17
<PAGE>
 
   
distributions paid to the investor during the preceding year. Be sure to keep
this statement as a permanent record. A fee may be charged for any duplicate
information that an investor requests.     
   
NOTE:   The foregoing summarizes certain tax consequences of investing in the
        Funds. Before investing, an investor should consult his or her own tax
        adviser for more information concerning the federal, foreign, state
        and local tax consequences of investing in, redeeming or exchanging
        Fund shares.     
 
                                      18
<PAGE>
 
INVESTMENT ADVISER
Loomis, Sayles & Company, L.P.
One Financial Center Boston,
Massachusetts 02111
 
DISTRIBUTOR 
Loomis Sayles Distributors, L.P.
One Financial Center Boston,
Massachusetts 02111
 
TRANSFER AND DIVIDEND PAYING AGENT
AND CUSTODIAN OF ASSETS
State Street Bank and Trust Company
Boston, Massachusetts 02102
 
SHAREHOLDER SERVICING AGENT FOR
STATE STREET BANK AND TRUST COMPANY 
Boston Financial Data Services, Inc.
P.O. Box 8314 Boston, Massachusetts 02266
 
LEGAL COUNSEL
Ropes & Gray
One International Place
Boston, Massachusetts 02110

   
INDEPENDENT ACCOUNTANTS
PricewaterhouseCoopers LLP One Post Office
Square Boston, Massachusetts 02109     
<PAGE>

[LOGO OF LOOMIS SAYLES FUNDS APPEARS HERE]
 
 ONE FINANCIAL CENTER . BOSTON, MASSACHUSETTS 02111 . (800) 633-3330
 
THE LOOMIS SAYLES FUNDS
 
 INSTITUTIONAL CLASS SHARES OF LOOMIS SAYLES BOND FUND
<PAGE>
 
PROSPECTUS                                                    
                                                           JANUARY 1, 1999     
 
LOOMIS SAYLES BOND FUND
  Loomis Sayles Bond Fund (the "Fund") is a series of Loomis Sayles Funds (the
"Trust"), a registered open-end management investment company, and is a no-
load mutual fund. Loomis, Sayles & Company, L.P. ("Loomis Sayles") is the
investment adviser of the Fund.
   
  The Fund offers three classes of shares: an Institutional Class that is
described in this Prospectus, a Retail Class, which has a lower investment
minimum, bears higher expenses, and is described in a separate prospectus, and
an Admin Class, bearing higher expenses than the Institutional or Retail
Class, that is described in a separate prospectus. This Prospectus concisely
describes the information that an investor should know before investing in the
Institutional Class shares of the Fund. Please read it carefully and keep it
for future reference. A Statement of Additional Information (SAI) dated
January 1, 1999, as revised from time to time, is available free of charge;
write to Loomis Sayles Distributors, L.P. (the "Distributor"), One Financial
Center, Boston, Massachusetts 02111 or telephone 800-633-3330. The SAI, which
contains more detailed information about the Fund, has been filed with the
Securities and Exchange Commission (the "SEC") and is available along with
other related materials on the SEC's Internet Website (http://www.sec.gov).
The SAI is incorporated herein by reference (legally forms a part of the
Prospectus). To obtain more information about the Retail Class or Admin Class
of shares, please call the Distributor toll-free at 800-633-3330, contact your
financial intermediary, or visit our Internet Website
(http://www.loomissayles.com).     
 
  For information about:                    For all other information about
   .Establishing an account                 the Funds:
   .Account procedures and status           CALL 800-633-3330
   .Exchanges
   .Shareholder services
  CALL 800-626-9390
 
  THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS
A CRIMINAL OFFENSE.
 
 
 
                                       1
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>   
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
SUMMARY OF EXPENSES.......................................................   3
FINANCIAL HIGHLIGHTS......................................................   4
THE TRUST.................................................................   5
INVESTMENT OBJECTIVES AND POLICIES........................................   5
MORE INFORMATION ABOUT THE FUND'S INVESTMENTS AND RISK CONSIDERATIONS.....   6
THE FUND'S INVESTMENT ADVISER.............................................  16
FUND EXPENSES.............................................................  16
PORTFOLIO TRANSACTIONS....................................................  17
HOW TO PURCHASE SHARES....................................................  17
SHAREHOLDER SERVICES......................................................  20
HOW TO REDEEM SHARES......................................................  20
CALCULATION OF PERFORMANCE INFORMATION....................................  22
DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES...........................  23
APPENDIX A
  DESCRIPTION OF BOND RATINGS.............................................  25
</TABLE>    
 
                                       2
<PAGE>
 
                              SUMMARY OF EXPENSES
                (FOR AN INSTITUTIONAL CLASS SHARE OF THE FUND)
   
  The following information is provided as an aid in understanding the various
expenses that an investor in the Fund will bear indirectly. The information is
based on expenses for the Fund's most recent fiscal year. The information
below should not be considered a representation of past or future expenses, as
actual expenses may be greater or less than those shown. Also, the 5% annual
return assumed in the Example should not be considered a representation of
investment performance, as actual performance will vary.     
 
<TABLE>   
<CAPTION>
 <S>                                                                  <C>
 Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on Purchases (as % of offering price)...  none
 Maximum Sales Load Imposed on Reinvested Dividends (as % of
  offering price)...................................................  none
 Maximum Deferred Sales Load (as % of original purchase price or
  redemption proceeds)..............................................  none
 Redemption Fees/1.............................................../..  none
 Exchange Fees......................................................  none
 Annual Fund Operating Expenses (as a percentage of average net
  assets):
 Management Fees....................................................   .60%
 12b-1 Fees.........................................................  none
 Other Operating Expenses (after expense reimbursements)............   .15%(/2/)
 Total Fund Operating Expenses (after expense reimbursements).......   .75%(/2/)
 Example:
 An investor would pay the following expenses on a $1,000 investment
  assuming a 5% annual return (with or without a redemption at the
  end of each time period):
 One Year...........................................................   $ 8
 Three Years........................................................   $24
 Five Years.........................................................   $42
 Ten Years..........................................................   $93
</TABLE>    
- -----------
/1/A $5 charge applies to any wire transfer of redemption proceeds.
   
/2/Loomis Sayles has voluntarily agreed, for an indefinite period, to limit
   the Bond Fund's Total Operating Expenses to 0.75%. Without this agreement,
   Other Operating Expenses and Total Operating Expenses would have been 0.16%
   and 0.76%, respectively.     
 
                                       3
<PAGE>
 
                             FINANCIAL HIGHLIGHTS
                 (FOR AN INSTITUTIONAL CLASS SHARE OF THE FUND
                 OUTSTANDING THROUGHOUT THE INDICATED PERIODS)
   
  The financial highlights table that follows has been audited by
PricewaterhouseCoopers LLP, independent accountants. The following information
should be read in conjunction with the financial highlights, financial
statements and the notes thereto contained in the Fund's 1998 Annual Report,
which is incorporated by reference in this Prospectus and the Statement of
Additional Information.     
 
<TABLE>   
<CAPTION>
                           NINE MONTHS                                                              MAY 16**
                              ENDED                      YEAR ENDED DEC. 31,                           TO
                          SEPTEMBER 30*, ---------------------------------------------------------  DEC. 31,
                               1998         1997       1996      1995     1994     1993     1992      1991
                          -------------- ----------  --------  --------  -------  -------  -------  --------
<S>                       <C>            <C>         <C>       <C>       <C>      <C>      <C>      <C>
Net asset value,
 beginning of period....    $    12.83   $    12.38  $  12.29  $  10.05  $ 11.37  $ 10.36  $ 10.23   $10.00
                            ----------   ----------  --------  --------  -------  -------  -------   ------
Income from investment
 operations--
 Net investment income
  (loss)................          0.69         0.86      0.86      0.82     0.83     0.84     0.76     0.52
 Net realized and
  unrealized gain (loss)
  on investments........         (0.78)        0.67      0.35      2.32    (1.29)    1.43     0.67     0.36
                            ----------   ----------  --------  --------  -------  -------  -------   ------
 Total from investment
  operations............         (0.09)        1.53      1.21      3.14    (0.46)    2.27     1.43     0.88
                            ----------   ----------  --------  --------  -------  -------  -------   ------
 Less distributions--
 Dividends from net
  investment income.....         (0.44)       (0.86)    (0.86)    (0.82)   (0.84)   (0.81)   (0.76)   (0.52)
 Distributions in excess
  of net investment
  income................          0.00         0.00      0.00      0.00    (0.02)    0.00     0.00     0.00
 Distributions from net
  realized capital
  gains.................          0.00        (0.22)    (0.26)    (0.08)    0.00    (0.45)   (0.54)   (0.13)
                            ----------   ----------  --------  --------  -------  -------  -------   ------
 Total distributions....         (0.44)       (1.08)    (1.12)    (0.90)   (0.86)   (1.26)   (1.30)   (0.65)
                            ----------   ----------  --------  --------  -------  -------  -------   ------
Net asset value, end of
 period.................    $    12.30   $    12.83  $  12.38  $  12.29  $ 10.05  $ 11.37  $ 10.36   $10.23
                            ==========   ==========  ========  ========  =======  =======  =======   ======
Total return (%)***.....          (0.9)++      12.7      10.3      32.0     (4.1)    22.2     14.3      8.9
Net assets, end of
 period (000)...........    $1,455,312   $1,261,910  $541,244  $255,710  $82,985  $64,222  $18,472   $9,922
Ratio of operating
 expenses to average net
 assets (%)****.........          0.75+        0.75      0.75      0.79     0.84     0.94     1.00     1.00+
Ratio of net investment
 income to average net
 assets (%).............          7.34+        7.36      7.93      8.34     7.92     8.26     7.50     8.97+
Portfolio turnover rate
 (%)....................            24++         41        42        35       87      170      101      126
Without giving effect to
 voluntary expense
 limitations:
 The ratio of operating
  expenses to average
  net assets would have
  been (%)..............          0.76+        0.77      0.75      0.79     0.84     0.94     1.55     1.78+
 Net investment income
  per share would have
  been..................    $     0.69   $     0.85  $   0.86  $   0.82  $  0.83  $  0.84  $  0.70   $ 0.47
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fees and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
    
  ++ Periods less than one year are not annualized.     

NOTE: Further information about the Fund's performance is contained in the
      Fund's annual report to shareholders, which may be obtained without
      charge.
 
                                       4
<PAGE>
 
                                   THE TRUST
 
  The Fund is a series of Loomis Sayles Funds (the "Trust"). The Trust is a
diversified open-end management investment company organized as a
Massachusetts business trust on February 20, 1991. The Trust is authorized to
issue an unlimited number of full and fractional shares of beneficial interest
in multiple series. Shares are freely transferable and entitle shareholders to
receive dividends as determined by the Trust's board of trustees and to cast a
vote for each share held at shareholder meetings. The Trust does not generally
hold shareholder meetings and will do so only when required by law.
Shareholders may call meetings to consider removal of the Trust's trustees.
 
                       INVESTMENT OBJECTIVE AND POLICIES
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
   
  The Fund seeks to achieve its objective by normally investing substantially
all of its assets in fixed income securities, although up to 20% of its total
assets may be invested in preferred stocks. At least 65% of the Fund's total
assets will normally be invested in bonds. The fixed income securities in
which the Fund may invest include corporate securities, securities issued or
guaranteed by the U.S. Government or its authorities or instrumentalities
("U.S. Government Securities"), commercial paper, zero coupon securities,
mortgage-backed securities, stripped mortgage-backed securities,
collateralized mortgage obligations ("CMOs"), asset-backed securities, real
estate investment trusts ("REITs"), when-issued securities, Rule 144A
securities, repurchase agreements and convertible securities. The Fund may
engage in options and futures transactions, repurchase transactions, foreign
currency hedging transactions and swap transactions.     
   
  The Fund may invest any portion of its assets in securities of Canadian
issuers, and up to 20% of its total assets in securities of other foreign
issuers. The Fund may also invest up to 35% of its total assets in securities
of below investment grade quality (commonly known as "junk bonds"). Securities
of below investment grade quality are securities rated below the top four
rating categories by each major rating agency that has rated the security,
including securities in the lowest rating categories, and unrated securities
that Loomis Sayles determines to be of comparable quality.     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
                                       5
<PAGE>
 
<TABLE>   
<CAPTION>
               STANDARD & POOR'S MOODY'S
               ----------------- -------
      <S>      <C>               <C>
      AAA/Aa            %            %
      AA/Aa             %            %
      A/A               %            %
      BBB/Baa           %            %
      BB/Ba             %            %
      B/B               %            %
      CCC/Caa           %            %
      C/Ca              %            %
      D                 %
</TABLE>    
 
  For temporary defensive purposes, the Fund may invest any portion of its
assets in fixed income securities, cash or any other securities deemed
appropriate by Loomis Sayles. Except for the Fund's investment objective, and
any investment policies that are identified as "fundamental," all of the
investment policies of the Fund may be changed without a vote of Fund
shareholders.
 
                 MORE INFORMATION ABOUT THE FUND'S INVESTMENTS
                            AND RISK CONSIDERATIONS
 
DEBT AND OTHER FIXED INCOME SECURITIES
 
  The Fund may invest in fixed income securities of any maturity. Fixed income
securities pay a specified rate of interest or dividends, or a rate that is
adjusted periodically by reference to some specified index or market rate.
Fixed income securities include securities issued by federal, state, local and
foreign governments and related agencies, and by a wide range of private
issuers. Because interest rates vary, it is impossible to predict the income
of a Fund that invests in fixed income securities for any particular period.
The net asset value of such a Fund's shares will vary as a result of changes
in the value of the securities in the Fund's portfolio.
 
  Fixed income securities are subject to market and credit risk. Market risk
relates to changes in a security's value as a result of changes in interest
rates generally. In general, the values of fixed income securities increase
when prevailing interest rates fall and decrease when interest rates rise.
Credit risk relates to the ability of the issuer to make payments of principal
and interest.
 
U.S. GOVERNMENT SECURITIES
 
  U.S. Government Securities have different kinds of government support. For
example, some U.S. Government Securities, such as U.S. Treasury bonds, are
supported by the full faith and credit of the United States, whereas certain
other U.S. Government Securities issued or guaranteed by federal agencies or
government-sponsored enterprises are not supported by the full faith and
credit of the United States.
 
 
                                       6
<PAGE>
 
  Although U.S. Government Securities generally do not involve the credit
risks associated with other types of fixed income securities, the market
values of U.S. Government Securities do go up and down as interest rates
change. Thus, for example, the value of an investment in a Fund that holds
U.S. Government Securities may fall during times of rising interest rates.
Yields on U.S. Government Securities tend to be lower than those on corporate
securities of comparable maturities.
 
  Some U.S. Government Securities, such as Government National Mortgage
Association Certificates ("GNMA"), are known as "mortgage-backed" securities.
Interest and principal payments on the mortgages underlying mortgage-backed
U.S. Government Securities are passed through to the holders of the security.
If the Fund purchases mortgage-backed securities at a discount or a premium,
the Fund will recognize a gain or loss when the payments of principal, through
prepayment or otherwise, are passed through to the Fund and, if the payment
occurs in a period of falling interest rates, the Fund may not be able to
reinvest the payment at as favorable an interest rate. As a result of these
principal prepayment features, mortgage-backed securities are generally more
volatile investments than many other fixed income securities.
 
  In addition to investing directly in U.S. Government Securities, the Fund
may purchase certificates of accrual or similar instruments ("strips")
evidencing undivided ownership interests in interest payments or principal
payments, or both, in U.S. Government Securities. These investment instruments
may be highly volatile.
 
LOWER RATED FIXED INCOME SECURITIES
   
  The Fund may invest up to 35% of its total assets in securities rated below
investment grade (commonly referred to as "junk bonds"). A security will be
treated as being of investment grade quality if at the time the Fund acquires
it at least one major rating agency has rated the security in its top four
rating categories (even if another such agency has issued a lower rating), or
if the security is unrated but Loomis Sayles determines it to be of investment
grade quality. Lower rated fixed income securities generally provide higher
yields, but are subject to greater credit and market risk, than higher quality
fixed income securities. Lower rated fixed income securities are considered
predominantly speculative with respect to the ability of the issuer to meet
principal and interest payments. Achievement of the investment objective of a
Fund investing in lower rated fixed income securities may be more dependent on
Loomis Sayles' own credit analysis than is the case with higher quality bonds.
The market for lower rated fixed income securities may be more severely
affected than some other financial markets by economic recession or
substantial interest rate increases, by changing public perceptions of this
market or by legislation that limits the ability of certain categories of
financial institutions to invest in these securities. In     
 
                                       7
<PAGE>
 
addition, the secondary market may be less liquid for lower rated fixed income
securities. This lack of liquidity at certain times may affect the values of
these securities and may make the evaluation and sale of these securities more
difficult. Securities in the lowest rating categories may be in poor standing
or in default. Securities in the lowest investment grade category (BBB or Baa)
have some speculative characteristics.
 
  For more information about the ratings services' descriptions of the various
rating categories, see Appendix A.
 
COMMON STOCKS AND OTHER EQUITY SECURITIES
 
  Common stocks and similar equity securities, such as warrants and
convertibles, are volatile and more risky than some other forms of investment.
The value of an investment in a Fund that invests in equity securities may
sometimes decrease. Equity securities of companies with relatively small
market capitalization may be more volatile than the securities of larger, more
established companies and than the broad equity market indexes.
 
ZERO COUPON SECURITIES
 
  The Fund may invest in "zero coupon" fixed income securities. These
securities accrue interest at a specified rate, but do not pay interest in
cash on a current basis. The Fund is required to distribute the income on
these securities to Fund shareholders as the income accrues, even though the
Fund is not receiving the income in cash on a current basis. Thus the Fund may
have to sell other investments to obtain cash to make income distributions at
times when Loomis Sayles would not otherwise deem it advisable to do so. The
market value of zero coupon securities is often more volatile than that of
non-zero coupon fixed income securities of comparable quality and maturity.
 
MORTGAGE-BACKED SECURITIES
   
  The Fund may invest in mortgage-backed securities, such as GNMA or Fannie
Mae certificates, which differ from traditional debt securities. Among the
major differences are that interest and principal payments are made more
frequently, usually monthly, and that principal may be prepaid at any time
because the underlying mortgage loans generally may be prepaid at any time. As
a result, if the Fund purchases these assets at a premium, a faster-than-
expected prepayment rate will reduce yield to maturity, and a slower-than-
expected prepayment rate will increase yield to maturity. If the Fund
purchases mortgage-backed securities at a discount, faster-than-expected
prepayments will increase, and slower-than-expected prepayments will reduce,
yield to maturity. Prepayments, and resulting amounts available for
reinvestment by the Fund, are likely to be greater during a period of
declining interest rates and, as a result, are likely to be reinvested at
lower interest rates. Accelerated prepayments on securities purchased at a
premium may result in a loss of principal if the     
 
                                       8
<PAGE>
 
premium has not been fully amortized at the time of prepayment. Although these
securities will decrease in value as a result of increases in interest rates
generally, they are likely to appreciate less than other fixed-income
securities when interest rates decline because of the risk of prepayments.
 
STRIPPED MORTGAGE-BACKED SECURITIES
 
  The Fund may invest in interest-only and principal-only ("IOs" and "POs")
classes of mortgage-backed securities. The yield to maturity on an IO or PO is
extremely sensitive not only to changes in prevailing interest rates but also
to the rate of principal payments (including prepayments) on the underlying
assets. A rapid rate of principal prepayments may have a measurably adverse
effect on the Fund's yield to maturity to the extent it invests in IOs. If the
assets underlying the IOs experience greater than anticipated prepayments of
principal, the Fund may fail to recoup fully its initial investment in these
securities. Conversely, POs tend to increase in value if prepayments are
greater than anticipated and decline if prepayments are slower than
anticipated.
 
  The secondary market for stripped mortgage-backed securities may be more
volatile and less liquid than that for other mortgage-backed securities,
potentially limiting the Fund's ability to buy or sell those securities at any
particular time.
 
COLLATERALIZED MORTGAGE OBLIGATIONS
 
  The Fund may invest in CMOs. A CMO is a security backed by a portfolio of
mortgages or mortgage-backed securities held under an indenture. CMOs may be
issued either by U.S. Government instrumentalities or by non-governmental
entities. The issuer's obligation to make interest and principal payments is
secured by the underlying portfolio of mortgages or mortgage-backed
securities. CMOs are issued with a number of classes or series which have
different maturities and which may represent interests in some or all of the
interest or principal on the underlying collateral or a combination thereof.
CMOs of different classes are generally retired in sequence as the underlying
mortgage loans in the mortgage pool are repaid. In the event of sufficient
early prepayments on such mortgages, the class or series of CMOs first to
mature generally will be retired prior to its maturity. As with other
mortgage-backed securities, the early retirement of a particular class or
series of CMOs held by the Fund could involve the loss of any premium the Fund
paid when it acquired the investment and could result in the Fund's
reinvesting the proceeds at a lower interest rate than the retired CMO paid.
Because of the early retirement feature, CMOs may be more volatile than many
other fixed-income investments.
 
ASSET-BACKED SECURITIES
 
  The Fund may invest in asset-backed securities. Through the use of trusts
and special purpose corporations, automobile and credit card receivables are
 
                                       9
<PAGE>
 
securitized in pass-through structures similar to mortgage pass-through
structures or in a pass-through structure similar to the CMO structure.
Generally, the issuers of asset-backed bonds, notes or pass-through
certificates are special purpose entities and do not have any significant
assets other than the receivables securing such obligations. In general, the
collateral supporting asset-backed securities is of shorter maturity than
mortgage loans. Instruments backed by pools of receivables are similar to
mortgage-backed securities in that they are subject to unscheduled prepayments
of principal prior to maturity. When the obligations are prepaid, the Fund
will ordinarily reinvest the prepaid amounts in securities the yields of which
reflect interest rates prevailing at the time. Therefore, the Fund's ability
to maintain a portfolio that includes high-yielding asset-backed securities
will be adversely affected to the extent that prepayments of principal must be
reinvested in securities that have lower yields than the prepaid obligations.
Moreover, prepayments of securities purchased at a premium could result in a
realized loss.
 
WHEN-ISSUED SECURITIES
 
  The Fund may purchase securities on a "when-issued" basis. This means that
the Fund will enter into a commitment to buy the security before the security
has been issued. The Fund's payment obligation and the interest rate on the
security are determined when the Fund enters into the commitment. The security
is typically delivered to the Fund 15 to 120 days later. No interest accrues
on the security between the time the Fund enters into the commitment and the
time the security is delivered. If the value of the security being purchased
falls between the time the Fund commits to buy it and the payment date, the
Fund may sustain a loss. The risk of this loss is in addition to the Fund's
risk of loss on the securities actually in its portfolio at the time. In
addition, when the Fund buys a security on a when-issued basis, it is subject
to the risk that market rates of interest will increase before the time the
security is delivered, with the result that the yield on the security
delivered to the Fund may be lower than the yield available on other,
comparable securities at the time of delivery. If the Fund has outstanding
obligations to buy when-issued securities, it will maintain liquid assets in a
segregated account at its custodian bank in an amount sufficient to satisfy
these obligations.
   
CONVERTIBLE SECURITIES     
   
  Convertible securities include corporate bonds, notes or preferred stocks of
U.S. or foreign issuers that can be converted into (that is, exchanged for)
common stocks or other equity securities at a stated price or rate.
Convertible securities also include other securities, such as warrants, that
provide an opportunity for equity participation. Because convertible
securities can be converted into equity securities, their value will normally
vary in some proportion with those of the underlying equity securities.
Convertible securities     
 
                                      10
<PAGE>
 
   
usually provide a higher yield than the underlying equity security, however,
so that when the price of the underlying equity security falls, the decline in
the price of the convertible security may sometimes be less substantial than
that of the underlying equity security. Due to the conversion feature,
convertible securities generally yield less than nonconvertible fixed income
securities of similar credit quality and maturity. The Fund's investment in
convertible securities may at times include securities that have a mandatory
conversion feature, pursuant to which the securities convert automatically
into common stock at a specified date and conversion ratio, or that are
convertible at the option of the issuer. Because conversion is not at the
option of the holder, the Fund may be required to convert the security into
the underlying common stock even at times when the value of the underlying
common stock has declined substantially.     
   
REAL ESTATE INVESTMENT TRUSTS     
   
  The Fund may invest in REITs. REITs involve certain unique risks in addition
to those risks associated with investing in the real estate industry in
general (such as possible declines in the value of real estate, lack of
availability of mortgage funds or extended vacancies of property). Equity
REITs may be affected by changes in the value of the underlying property owned
by the REITs, while mortgage REITs may be affected by the quality of any
credit extended. REITs are dependent upon management skills, are not
diversified, are subject to heavy cash flow dependency, risks of default by
borrowers and self-liquidation. REITs are also subject to the possibilities of
failing to qualify for tax-free pass-through of income under the Code, and
failing to maintain their exemptions from registration under the Investment
Company Act of 1940 (the "1940 Act").     
   
  Investment in REITs involves risk similar to those associated with investing
in small capitalization companies. REITs may have limited financial resources,
may trade less frequently and in a limited volume and may be subject to more
abrupt or erratic price movements than larger securities.     
 
RULE 144A SECURITIES
 
  The Fund may invest in Rule 144A securities, which are privately offered
securities that can be resold only to certain qualified institutional buyers.
Rule 144A securities are treated as illiquid, unless Loomis Sayles has
determined, under guidelines established by the Trust's trustees, that the
particular issue of Rule 144A securities is liquid.
 
FOREIGN SECURITIES
 
  The Fund may invest in securities of issuers organized or headquartered
outside the United States ("foreign securities"). The Fund may invest any
 
                                      11
<PAGE>
 
portion of its assets in securities of Canadian issuers, but will not purchase
foreign securities other than those of Canadian issuers if, as a result, the
Fund's holdings of non-U.S. and non-Canadian securities would exceed 20% of
the Fund's total assets.
 
  Although investing in foreign securities may increase the Fund's
diversification and reduce portfolio volatility, foreign securities may
present risks not associated with investments in comparable securities of U.S.
issuers. There may be less information publicly available about a foreign
corporate or government issuer than about a U.S. issuer, and foreign corporate
issuers are not generally subject to accounting, auditing and financial
reporting standards and practices comparable to those in the United States.
The securities of some foreign issuers are less liquid and at times more
volatile than securities of comparable U.S. issuers. Foreign brokerage
commissions and securities custody costs are often higher than in the United
States. With respect to certain foreign countries, there is a possibility of
governmental expropriation of assets, confiscatory taxation, political or
financial instability and diplomatic developments that could affect the value
of investments in those countries. The Fund's receipt of interest on foreign
government securities may depend on the availability of tax or other revenues
to satisfy the issuer's obligations.
 
  The Fund's investments in foreign securities may include investments in
countries whose economies or securities markets are not yet highly developed.
Special considerations associated with these investments (in addition to the
considerations regarding foreign investments generally) may include, among
others, greater political uncertainties, an economy's dependence on revenues
from particular commodities or on international aid or development assistance,
currency transfer restrictions, highly limited numbers of potential buyers for
such securities and delays and disruptions in securities settlement
procedures.
 
  Since most foreign securities are denominated in foreign currencies or
traded primarily in securities markets in which settlements are made in
foreign currencies, the value of these investments and the net investment
income available for distribution to shareholders of a Fund investing in these
securities may be affected favorably or unfavorably by changes in currency
exchange rates, exchange control regulations or foreign withholding taxes.
Changes in the value relative to the U.S. dollar of a foreign currency in
which the Fund's holdings are denominated will result in a change in the U.S.
dollar value of the Fund's assets and the Fund's income available for
distribution.
 
  In addition, although part of the Fund's income may be received or realized
in foreign currencies, the Fund will be required to compute and distribute its
income in U.S. dollars. Therefore, if the value of a currency relative to the
U.S. dollar declines after the Fund's income has been earned in that currency,
translated into U.S. dollars and declared as a dividend, but before payment of
 
                                      12
<PAGE>
 
the dividend, the Fund could be required to liquidate portfolio securities to
pay the dividend. Similarly, if the value of a currency relative to the U.S.
dollar declines between the time the Fund accrues expenses in U.S. dollars and
the time such expenses are paid, the amount of such currency required to be
converted into U.S. dollars will be greater than the equivalent amount in such
currency of such expenses at the time they were incurred.
 
  In determining whether to invest assets of the Fund in securities of a
particular foreign issuer, Loomis Sayles will consider the likely effects of
foreign taxes on the net yield available to the Fund and its shareholders.
Compliance with foreign tax law may reduce a Fund's net income available for
distribution to shareholders.
 
FOREIGN CURRENCY HEDGING TRANSACTIONS
 
  The Fund may engage in foreign currency exchange transactions to protect the
value of specific portfolio positions or in anticipation of changes in
relative values of currencies in which current or future Fund portfolio
holdings are denominated or quoted. For example, to protect against a change
in the foreign currency exchange rate between the date on which the Fund
contracts to purchase or sell a security and the settlement date for the
purchase or sale, or to "lock in" the equivalent of a dividend or interest
payment in another currency, the Fund might purchase or sell a foreign
currency on a spot (that is, cash) basis at the prevailing spot rate. If
conditions warrant, the Fund may also enter into private contracts to purchase
or sell foreign currencies at a future date ("forward contracts"). The Fund
might also purchase exchange-listed and over-the-counter call and put options
on foreign currencies. Over-the-counter currency options are generally less
liquid than exchange-listed options, and will be treated as illiquid assets.
The Fund may not be able to dispose of over-the-counter options readily.
 
  Foreign currency transactions involve costs and may result in losses.
 
SWAP TRANSACTIONS
 
  The Fund may enter into interest rate or currency swaps. The Fund will enter
into these transactions primarily to preserve a return or spread on a
particular investment or portion of its portfolio, to protect against currency
fluctuations, as a duration management technique or to protect against any
increase in the price of securities the Fund anticipates purchasing at a later
date. Interest rate swaps involve the exchange by a Fund with another party of
their respective commitments to pay or receive interest (for example, an
exchange of floating rate payments for fixed rate payments with respect to a
notional amount of principal). A currency swap is an agreement to exchange
cash flows on a notional amount based on changes in the relative values of the
specified
 
                                      13
<PAGE>
 
currencies. The Fund will maintain liquid assets in a segregated custodial
account to cover its current obligations under swap agreements. Because swap
agreements are not exchange-traded, but are private contracts into which the
Fund and a swap counterparty enter as principals, the Fund may experience a
loss or delay in recovering assets if the counterparty were to default on its
obligations.
 
OPTIONS AND FUTURES TRANSACTIONS
 
  The Fund may buy, sell or write options on securities, securities indexes,
currencies or futures contracts and may buy and sell futures contracts on
securities, securities indexes or currencies. The Fund may engage in these
transactions either for the purpose of enhancing investment return, or to
hedge against changes in the value of other assets that the Funds own or
intend to acquire. Options and futures fall into the broad category of
financial instruments known as "derivatives" and involve special risks. Use of
options or futures for other than hedging purposes may be considered a
speculative activity, involving greater risks than are involved in hedging.
 
  Options can generally be classified as either "call" or "put" options. There
are two parties to a typical options transaction: the "writer" and the
"buyer." A call option gives the buyer the right to buy a security or other
asset (such as an amount of currency or a futures contract) from, and a put
option gives the buyer the right to sell a security or other asset to, the
option writer at a specified price, on or before a specified date. The buyer
of an option pays a premium when purchasing the option, which reduces the
return on the underlying security or other asset if the option is exercised,
and results in a loss if the option expires unexercised. The writer of an
option receives a premium from writing an option, which may increase its
return if the option expires or is closed out at a profit. If the Fund as the
writer of an option is unable to close out an unexpired option, it must
continue to hold the underlying security or other asset until the option
expires, to "cover" its obligation under the option.
 
  A futures contract creates an obligation by the seller to deliver and the
buyer to take delivery of the type of instrument or cash at the time and in
the amount specified in the contract. Although many futures contracts call for
the delivery (or acceptance) of the specified instrument, futures are usually
closed out before the settlement date through the purchase (or sale) of a
comparable contract. If the price of the sale of the futures contract by the
Fund exceeds (or is less than) the price of the offsetting purchase, the Fund
will realize a gain (or loss).
 
  The value of options purchased by a Fund and futures contracts held by the
Fund may fluctuate based on a variety of market and economic factors. In some
cases, the fluctuations may offset (or be offset by) changes in the value of
 
                                      14
<PAGE>
 
securities held in the Fund's portfolio. All transactions in options and
futures involve the possible risk of loss to the Fund of all or a significant
part of the value of its investment. In some cases, the risk of loss may
exceed the amount of the Fund's investment. When the Fund writes a call option
or sells a futures contract without holding the underlying securities,
currencies or futures contracts, its potential loss is unlimited. The Fund
will be required, however, to set aside with its custodian bank liquid assets
in amounts sufficient at all times to satisfy its obligations under options
and futures contracts.
 
  The successful use of options and futures will usually depend on Loomis
Sayles' ability to forecast stock market, currency or other financial market
movements correctly. The Fund's ability to hedge against adverse changes in
the value of securities held in its portfolio through options and futures also
depends on the degree of correlation between changes in the value of futures
or options positions and changes in the values of the portfolio securities.
The successful use of futures and exchange traded options also depends on the
availability of a liquid secondary market to enable the Fund to close its
positions on a timely basis. There can be no assurance that such a market will
exist at any particular time. In the case of options that are not traded on an
exchange ("over-the-counter" options), the Fund is at risk that the other
party to the transaction will default on its obligations, or will not permit
the Fund to terminate the transaction before its scheduled maturity. As a
result of these characteristics, the Fund will treat most over-the-counter
options (and the assets it segregates to cover its obligations thereunder) as
illiquid.
 
  The options and futures markets of foreign countries are small compared to
those of the United States and consequently are characterized in most cases by
less liquidity than are the U.S. markets. In addition, foreign markets may be
subject to less detailed reporting requirements and regulatory controls than
U.S. markets. Furthermore, investments in options in foreign markets are
subject to many of the same risks as other foreign investments. See "Foreign
Securities" above.
 
REPURCHASE AGREEMENTS
 
  The Fund may invest in repurchase agreements. In repurchase agreements, the
Fund buys securities from a seller, usually a bank or brokerage firm, with the
understanding that the seller will repurchase the securities at a higher price
at a later date. Such transactions afford an opportunity for the Fund to earn
a return on available cash at minimal market risk, although the Fund may be
subject to various delays and risks of loss if the seller is unable to meet
its obligations to repurchase.
 
YEAR 2000
 
  Many computer software systems in use today cannot properly process date-
related information from and after January 1, 2000. Should any of the
 
                                      15
<PAGE>
 
computer systems employed by the Fund's major service providers fail to
process this type of information properly, that could have a negative impact
on the Fund's operations and the services that are provided to the Fund's
shareholders. Loomis Sayles and the Distributor have each advised the Fund
that they are reviewing all of their computer systems with the goal of
modifying or replacing such systems prior to January 1, 2000, to the extent
necessary to foreclose any such negative impact. In addition, Loomis Sayles
has been advised by the Fund's custodian that it is also in the process of
reviewing its systems with the same goal. As of the date of this prospectus,
the Fund and Loomis Sayles have no reason to believe that these goals will not
be achieved. Similarly, the values of certain of the portfolio securities held
by the Fund may be adversely affected by the inability of the securities'
issuers or of third parties to process this type of information properly.
 
                         THE FUNDS' INVESTMENT ADVISER
 
  The Fund's investment adviser is Loomis Sayles, One Financial Center,
Boston, Massachusetts 02111. Founded in 1926, Loomis Sayles is one of the
country's oldest and largest investment firms. The general partner of Loomis
Sayles is a special purpose corporation that is an indirect wholly-owned
subsidiary of Nvest Companies, L.P. ("Nvest Companies"). Nvest Companies'
managing general partner, Nvest Corporation, is a direct wholly-owned
subsidiary of Metropolitan Life Insurance Company ("Met Life"), a mutual life
insurance company. Nvest Companies' advising general partner, Nvest, L.P., is
a publicly traded company listed on the New York Stock Exchange. Nvest
Corporation is the sole general partner of Nvest L.P.
 
  In addition to selecting and reviewing the Fund's investments, Loomis Sayles
provides executive and other personnel for the management of the Fund. The
Loomis Sayles Funds' board of trustees supervises Loomis Sayles' conduct of
the affairs of the Fund.
       
   
  As of October 31, 1998, Charles Schwab & Co. Inc. owned 48% of the Bond
Fund. Shareholders holding more than 25% of a Fund's shares may be deemed to
control the relevant Fund.     
 
  Daniel J. Fuss, President of the Trust and Executive Vice President of
Loomis Sayles, has served as the portfolio manager of the Bond Fund since its
commencement of investment operations in 1991. Kathleen C. Gaffney, Vice
President of the Trust and Loomis Sayles, has served as associate portfolio
manager of the Bond Fund since October 1997. Both Mr. Fuss and Ms. Gaffney
have been employed by Loomis Sayles for more than five years.
 
                                 FUND EXPENSES
 
  The Fund pays Loomis Sayles a monthly investment advisory fee of .60% of the
Fund's average daily net assets. In addition to the investment advisory
 
                                      16
<PAGE>
 
fee, the Fund pays all expenses not expressly assumed by Loomis Sayles,
including taxes, brokerage commissions, fees and expenses of registering or
qualifying the Fund's shares under federal and state securities laws, fees of
the Fund's custodian, transfer agent, independent accountants and legal
counsel, expenses of shareholders' and trustees' meetings, expenses of
preparing, printing and mailing prospectuses to existing shareholders and fees
of trustees who are not directors, officers or employees of Loomis Sayles or
its affiliated companies.
   
  Loomis Sayles has voluntarily agreed, for an indefinite period, to reduce
its advisory fees and/or bear other Fund expenses to the extent necessary to
limit total annual operating expenses of the Institutional Class shares of the
Fund to .75% of the Fund's average daily net assets. Loomis Sayles may change
or terminate this voluntary arrangement at any time, but the Fund's Prospectus
would be supplemented to describe the change.     
 
  Loomis Sayles may pay certain broker-dealers and financial intermediaries
whose customers own shares of the Funds a continuing fee in an amount of up to
 .25% annually of the value of Fund shares held for those customers' accounts.
These fees are paid by Loomis Sayles out of its own assets and are not
assessed against the Fund.
 
                            PORTFOLIO TRANSACTIONS
 
  Portfolio turnover considerations will not limit Loomis Sayles' investment
discretion in managing the Fund's assets. The Fund anticipates that its
portfolio turnover rates will vary significantly from time to time depending
on the volatility of economic and market conditions. High portfolio turnover
may involve higher costs and higher levels of taxable gains.
 
                            HOW TO PURCHASE SHARES
 
  An investor may make an initial purchase of shares of the Fund by submitting
a completed application form and payment to:
 
      Boston Financial Data Services
      P.O. Box 8314
      Boston, Massachusetts 02266-8314
      Attn: Loomis Sayles Funds
 
  The minimum initial investment for the Institutional Class of shares of the
Fund is $25,000. A $2,500 minimum investment applies to the current and
retired trustees of the Trust, investment advisory clients of Loomis Sayles
(and their directors, officers and employees), and current and retired
employees of
 
                                      17
<PAGE>
 
Loomis Sayles and the parents, spouses and children of the foregoing. The
minimum investment may be waived in whole or in part by Loomis Sayles in its
sole discretion. Subsequent investments must be at least $50.
 
  Shares of the Fund may be purchased by (i) cash, (ii) exchanging
Institutional Class shares of any Fund (or any other series of Loomis Sayles
Funds), provided the value of the shares exchanged meets the investment
minimum of the Fund into which the exchange is made, (iii) exchanging
securities on deposit with a custodian acceptable to Loomis Sayles or (iv) a
combination of such securities and cash. Loomis Sayles will not approve the
acceptance of securities in exchange for shares of the Fund unless (1) Loomis
Sayles, in its sole discretion, believes the securities are appropriate
investments for the Fund; (2) the investor represents and agrees that all
securities offered to the Fund can be resold by the Fund without restriction
under the Securities Act of 1933, as amended (the "Securities Act") or
otherwise; and (3) the securities are eligible to be acquired under the Fund's
investment policies and restrictions. No investor owning 5% or more of the
Fund's shares may purchase additional shares of the Fund by exchange of
securities.
 
  In all cases Loomis Sayles reserves the right to reject any securities that
are proposed for exchange. Securities accepted by Loomis Sayles in exchange
for Fund shares will be valued in the same manner as the Fund's assets as
described below as of the time of the Fund's next determination of net asset
value after such acceptance. All dividends and subscription or other rights
which are reflected in the market price of accepted securities at the time of
valuation become the property of the Fund and must be delivered to the Fund
upon receipt by the investor from the issuer. A gain or loss for federal
income tax purposes would be realized upon the exchange by an investor that is
subject to federal income taxation, depending upon the investor's basis in the
securities tendered. An investor who wishes to purchase shares by exchanging
securities should obtain instructions by calling 800-633-3330, option 5.
 
  All purchases made by check should be in U.S. dollars and made payable to
State Street Bank and Trust Company. Third party checks will not be accepted.
When purchases are made by check or periodic account investment, redemption
will not be allowed until the investment being redeemed has been in the
account for 15 calendar days.
 
  Upon acceptance of an investor's order, BFDS opens an account, applies the
payment to the purchase of full and fractional Fund shares and mails a
statement of the account confirming the transaction.
 
  After an account has been established, an investor may send subsequent
investments at any time directly to BFDS at the above address. The remittance
must be accompanied by either the account identification slip detached from a
 
                                      18
<PAGE>
 
statement of account or a note containing sufficient information to identify
the account, i.e., the Fund name and the investor's account number or name and
social security number.
 
  Subsequent investments can also be made by federal funds wire. Investors
should instruct their banks to wire federal funds to State Street Bank and
Trust Company, ABA #011000028. The text of the wire should read as follows:
"$_____ amount, STATE STREET BOS ATTN Mutual Funds. Credit Fund (Fund Name and
Institutional Class), DDA #9904-622-9, Account Name, Account Number." A bank
may charge a fee for transmitting funds by wire.
 
  The Fund and the Distributor reserve the right to reject any purchase order,
including orders in connection with exchanges, for any reason which the Fund
or the Distributor in its sole discretion deems appropriate. Although the Fund
does not presently anticipate that it will do so, the Fund reserves the right
to suspend or change the terms of the offering of its shares.
 
  The price an investor pays will be the per share net asset value next
calculated after a proper investment order is received by the Trust's transfer
or other agent or subagent. Shares of the Fund are sold with no sales charge.
The net asset value of the Fund's shares is calculated once daily as of the
close of regular trading on the New York Stock Exchange on each day the
Exchange is open for trading, by dividing the Fund's net assets by the number
of shares outstanding. Portfolio securities are valued at their market value
as more fully described in the Statement of Additional Information.
 
  The Distributor may accept telephone orders from broker-dealers who have
been previously approved by the Distributor. It is the responsibility of such
broker-dealers to promptly forward purchase or redemption orders to the
Distributor. Although there is no sales charge imposed by the Fund or the
Distributor, broker-dealers may charge the investor a transaction-based fee or
other fee for their services at either the time of purchase or the time of
redemption. Such charges may vary among broker-dealers but in all cases will
be retained by the broker-dealer and not remitted to the Fund.
 
  The Fund also offers a Retail Class of shares that bears higher expenses.
Because of its lower expenses, the Institutional Class of shares of the Fund
is expected to have a higher total return than the Retail Class of shares.
 
  The Loomis Sayles Bond Fund also offers an Admin Class of shares that is
offered exclusively through intermediaries, who will be the record owners of
the shares. Because of its lower expenses, the Institutional Class of shares
of the Loomis Sayles Bond Fund is expected to have a higher total return than
the Admin Class of shares.
 
                                      19
<PAGE>
 
                             SHAREHOLDER SERVICES
 
  The Fund offers the following shareholder services, which are more fully
described in the Statement of Additional Information. Explanations and forms
are available from BFDS. Telephone redemption and exchange privileges will be
established automatically when an investor opens an account unless an investor
elects on the application to decline the privileges. Other privileges must be
specifically elected. A signature guarantee will be required to establish a
privilege after an account is opened.
   
  FREE EXCHANGE PRIVILEGE. The Institutional Class shares of the Fund may be
exchanged for Institutional Class shares of any other fund that is a series of
Loomis Sayles Funds and that offers Institutional Class shares or for shares
of certain money market funds advised by New England Funds Management, L.P.,
an affiliate of Loomis Sayles, provided the value of the shares exchanged
meets the investment minimum of that Fund and, in the case of the Loomis
Sayles High Yield Fund and Loomis Sayles U.S. Government Securities Fund,
Loomis Sayles has approved the exchange of shares. Exchanges may be made by
written instructions or by telephone, unless an investor elected on the
application to decline telephone exchange privileges. The exchange privilege
should not be viewed as a means for taking advantage of short-term swings in
the market, and the Fund reserves the right to terminate or limit the
privilege of any shareholder who makes more than four exchanges in any
calendar year. The Fund may terminate or change the terms of the exchange
privilege at any time, upon 60 days' notice to shareholders. An exchange is a
taxable event for federal income tax purposes in which a gain or loss would be
realized by an investor that is subject to federal income taxation.     
 
  RETIREMENT PLANS. The Fund's shares may be purchased by all types of tax-
deferred retirement plans. Loomis Sayles makes available retirement plan forms
for IRAs.
 
  SYSTEMATIC WITHDRAWAL PLAN. If the value of an account is at least $25,000,
an investor may have periodic cash withdrawals automatically paid to the
investor or any person designated by the investor.
 
  AUTOMATIC INVESTMENT PLAN. Voluntary monthly investments of at least $50 may
be made automatically by pre-authorized withdrawals from an investor's
checking account.
 
                             HOW TO REDEEM SHARES
 
  An investor can redeem shares by sending a written request to Boston
Financial Data Services, Inc., P.O. Box 8314, Boston, Massachusetts 02266.
Proceeds from a written request may be sent to the investor in the form of a
check. As described below, an investor may also redeem shares by calling BFDS
 
                                      20
<PAGE>
 
at 800-626-9390. Proceeds resulting from a telephone redemption request can be
wired to an investor's bank account or sent by check in the name of the
registered owners to their record address.
 
  The written request must include the name of the Fund, the account number,
the exact name(s) in which the shares are registered, and the number of shares
or the dollar amount to be redeemed. All owners of the shares must sign the
request in the exact names in which the shares are registered (this appears on
an investor's confirmation statement) and should indicate any special capacity
in which they are signing (such as trustee or custodian or on behalf of a
partnership, corporation or other entity). Shareholders requesting that
redemption proceeds be wired to their bank accounts must provide specific wire
instructions.
 
  If (1) an investor is redeeming shares worth more than $50,000, (2) an
investor is requesting that the proceeds check be made out to someone other
than the registered owners or be sent to an address other than the record
address, (3) the account registration has changed within the last 30 days or
(4) an investor is instructing us to wire the proceeds to a bank account not
designated on the application, the investor must have his or her signature
guaranteed by an eligible guarantor. This requirement may be waived by Loomis
Sayles in its sole discretion. Eligible guarantors include commercial banks,
trust companies, savings associations, credit unions and brokerage firms that
are members of domestic securities exchanges. Before submitting the redemption
request, an investor should verify with the guarantor institution that it is
an eligible guarantor. Signature guarantees by notaries public are not
acceptable.
 
  When an investor telephones a redemption request, the proceeds are wired to
the bank account previously chosen by the investor. A wire fee (currently $5)
will be deducted from the proceeds. A telephonic redemption request must be
received by BFDS prior to the close of regular trading on the New York Stock
Exchange. If an investor telephones a request to BFDS after the Exchange
closes or on a day when the Exchange is not open for business, BFDS cannot
accept the request and a new one will be necessary.
 
  If an investor decides to change the bank account to which proceeds are to
be wired, the investor must send in this change in writing with a signature
guarantee. Telephonic redemptions may only be made if the investor's bank is a
member of the Federal Reserve System or has a correspondent bank that is a
member of the System. Unless an investor indicates otherwise on the account
application, BFDS will be authorized to act upon redemption and exchange
instructions received by telephone from the investor or any person claiming to
act as the investor's representative who can provide BFDS with the investor's
account registration and address as it appears on the records of State Street
Bank. BFDS will employ these or other reasonable procedures to confirm that
 
                                      21
<PAGE>
 
instructions communicated by telephone are genuine; the Fund, State Street
Bank, BFDS, the Distributor and Loomis Sayles will not be liable for any
losses due to unauthorized or fraudulent instructions if these or other
reasonable procedures are followed. For information, consult BFDS. In times of
heavy market activity, an investor who encounters difficulty in placing a
redemption or exchange order by telephone may wish to place the order by mail
as described above.
 
  The redemption price will be the net asset value per share next determined
after the redemption request and any necessary special documentation are
received by BFDS in proper form.
 
  Proceeds resulting from a written redemption request will normally be mailed
to an investor within seven days after receipt of the investor's request in
good order. Telephonic redemption proceeds will normally be wired to an
investor's bank on the first business day following receipt of a proper
redemption request. If an investor purchased shares by check and the check was
deposited less than 15 days prior to the redemption request, the Fund may
withhold redemption proceeds until the check has cleared.
 
  The Fund may suspend the right of redemption and may postpone payment for
more than seven days when the New York Stock Exchange is closed for other than
weekends or holidays, or if permitted by the rules of the SEC when trading on
the Exchange is restricted or during an emergency which makes it impracticable
for the Fund to dispose of its securities or to determine fairly the value of
its net assets, or during any other period permitted by the SEC for the
protection of investors.
 
                    CALCULATION OF PERFORMANCE INFORMATION
 
  The Fund's investment performance may from time to time be included in
advertisements about the Fund or Loomis Sayles Funds. "Yield" for each class
of shares is calculated by dividing the annualized net investment income per
share during a recent 30-day period by the maximum public offering price per
share of the class on the last day of that period.
 
  For purposes of calculating yield, net investment income is calculated in
accordance with SEC regulations and may differ from net investment income as
determined for financial reporting purposes. SEC regulations require that net
investment income be calculated on a "yield-to-maturity" basis, which has the
effect of amortizing any premiums or discounts in the current market value of
fixed income securities. The current dividend rate is based on net investment
income as determined for tax purposes, which may not reflect amortization in
the same manner.
 
                                      22
<PAGE>
 
  "Total return" for the one-, five- and ten-year periods (or for the life of
a class, if shorter) through the most recent calendar quarter represents the
average annual compounded rate of return on an investment of $1,000 in the
Fund. Total return may also be presented for other periods.
 
                DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES
 
  The Fund declares and pays dividends quarterly. The Fund also distributes
all of its net capital gains realized from the sale of portfolio securities.
Any capital gain distributions are normally made annually, but may, to the
extent permitted by law, be made more frequently as deemed advisable by the
trustees of the Trust. The Trust's trustees may change the frequency with
which the Fund declares or pays dividends.
   
  Dividends and capital gain distributions will automatically be reinvested in
additional shares of the Fund unless an investor has elected to receive cash.
    
  The Fund intends to qualify as a regulated investment company under the
Internal Revenue Code of 1986, as amended. As such, so long as the Fund
distributes substantially all its net investment income and net capital gains
to its shareholders, the Fund itself does not pay any federal income tax to
the extent such income and gains are so distributed.
   
  An investor's income dividends and short-term capital gain distributions are
taxable as ordinary income whether distributed in cash or additional shares.
Distributions designated by the Fund as deriving from net gains on securities
held for more than one year will be taxable as such (generally at a 20% rate
for noncorporate shareholders) whether distributed in cash or additional
shares and regardless of how long an investor has owned shares of the Fund.    
   
  A dividend or distribution made shortly after the purchase of shares of a
Fund by a shareholder, although in effect a return of capital to that
particular shareholder, would be taxable to him or her as described above. If
a shareholder held shares six months or less and during that period received a
distribution of net capital gains, any loss realized on the sale of such
shares during such six-month period would be a long-term capital loss to the
extent of such distribution.     
 
  The Fund is required to withhold 31% of any redemption proceeds (including
the value of shares exchanged) and all income dividends and capital gain
distributions it pays (1) if an investor does not provide a correct, certified
taxpayer identification number, (2) if the Fund is notified that an investor
has underreported income in the past, or (3) if an investor fails to certify
to the Fund that he or she is not subject to such withholding.
 
                                      23
<PAGE>
 
  Dividends derived from interest on U.S. Government Securities may be exempt
from state and local taxes.
 
  State Street Bank will send investors and the IRS an annual statement
detailing federal tax information, including information about dividends and
distributions paid during the preceding year. An investor should keep this
statement as a permanent record. A fee may be charged for any duplicate
information requested.
 
NOTE:    The foregoing summarizes certain tax consequences of investing in the
         Fund. Before investing, an investor should consult his or her own tax
         adviser for more information concerning the federal, foreign, state
         and local tax consequences of investing in, redeeming or exchanging
         Fund shares.
 
                                      24
<PAGE>
 
                                                                     APPENDIX A
 
                    DESCRIPTION OF BOND RATINGS ASSIGNED BY
                             STANDARD & POOR'S AND
                        MOODY'S INVESTORS SERVICE, INC.
 
STANDARD & POOR'S
 
                                      AAA
 
  This is the highest rating assigned by Standard & Poor's to a debt
obligation and indicates an extremely strong capacity to pay interest and
repay principal.
 
                                      AA
 
  Bonds rated AA also qualify as high quality debt obligations. Capacity to
pay interest and repay principal is very strong, and in the majority of
instances they differ from AAA issues only in small degree.
 
                                       A
 
  Bonds rated A have a strong capacity to pay interest and repay principal,
although they are somewhat more susceptible to the adverse effects of changes
in circumstances and economic conditions than obligations in higher rated
categories.
 
                                      BBB
 
  Bonds rated BBB are regarded as having an adequate capacity to pay interest
and repay principal. Whereas they normally exhibit adequate protection
parameters, adverse economic conditions or changing circumstances are more
likely to lead to a weakened capacity to repay principal and pay interest for
bonds in this category than for bonds in higher rated categories.
 
                                BB, B, CCC, CC
 
  Bonds rated BB, B, CCC and CC are regarded, on balance, as predominantly
speculative with respect to capacity to pay interest and repay principal in
accordance with the terms of the obligation. BB indicates the lowest degree of
speculation and CC the highest degree of speculation. While such bonds will
likely have some quality and protective characteristics, these are outweighed
by large uncertainties or major risk exposures to adverse conditions.
 
                                      25
<PAGE>
 
                                       C
 
  The rating C is reserved for income bonds on which no interest is being
paid.
 
                                       D
 
  Bonds rated D are in default, and payment of interest and/or repayment of
principal is in arrears.
 
                                       R
 
  This symbol is attached to the ratings of instruments with significant
noncredit risks such as risks to principal or volatility of expected returns.
 
  Plus (+) or Minus (-): The ratings from "AA" to "B" may be modified by the
addition of a plus or minus sign to show relative standing within the major
rating categories.
 
MOODY'S INVESTORS SERVICE, INC.
 
                                      AAA
 
  Bonds that are rated Aaa are judged to be of the best quality. They carry
the smallest degree of investment risk and are generally referred to as "gilt
edge." Interest payments are protected by a large, or by an exceptionally
stable, margin, and principal is secure. While the various protective elements
are likely to change, such changes as can be visualized are most unlikely to
impair the fundamentally strong position of such issues.
 
                                      AA
 
  Bonds that are rated Aa are judged to be high quality by all standards.
Together with the Aaa group they comprise what are generally known as high
grade bonds. They are rated lower than the best bonds because margins of
protection may not be as large as in Aaa securities or fluctuation of
protective elements may be of greater amplitude or there may be other elements
present that make the long-term risks appear somewhat larger than in Aaa
securities.
 
                                       A
 
  Bonds that are rated A possess many favorable investment attributes and are
to be considered as upper medium grade obligations. Factors giving security to
principal and interest are considered adequate, but elements may be present
that suggest a susceptibility to impairment sometime in the future.
 
                                      26
<PAGE>
 
                                      BAA
 
  Bonds that are rated Baa are considered as medium grade obligations; i.e.,
they are neither highly protected nor poorly secured. Interest payments and
principal security appear adequate for the present, but certain protective
elements may be lacking or may be characteristically unreliable over any great
length of time. Such bonds lack outstanding investment characteristics and, in
fact, have speculative characteristics as well.
 
                                      BA
 
  Bonds which are rated Ba are judged to have speculative elements; their
future cannot be considered as well assured. Often, the protection of interest
and principal payments may be very moderate, and thereby not well safeguarded
during both good and bad times over the future. Uncertainty of position
characterizes bonds in this class.
 
                                       B
 
  Bonds which are rated B generally lack characteristics of the desirable
investment. Assurance of interest and principal payments or of maintenance of
other terms of the contract over any long period of time may be small.
 
                                      CAA
 
  Bonds which are rated Caa are of poor standing. Such issues may be in
default or there may be present elements of danger with respect to principal
or interest.
 
                                      CA
 
  Bonds which are rated Ca represent obligations which are speculative in a
high degree. Such issues are often in default or have other marked
shortcomings.
 
                                       C
 
  Bonds which are rated C are the lowest rated class of bonds, and issues so
rated can be regarded as having extremely poor prospects of ever attaining any
real investment standing.
 
                                      27
<PAGE>
 
  Should no rating be assigned by Moody's, the reason may be one of the
following:
 
 1. An application for rating was not received or accepted.
 
 2. The issue or issuer belongs to a group of securities that are not rated
    as a matter of policy.
 
 3. There is a lack of essential data pertaining to the issue or issuer.
 
 4. The issue was privately placed in which case the rating is not published
    in Moody's publications.
 
  Suspension or withdrawal may occur if new and material circumstances arise,
the effects of which preclude satisfactory analysis; if there is no longer
available reasonable up-to-date data to permit a judgment to be formed; if a
bond is called for redemption; or for other reasons.
 
Note:  Those bonds in the Aa, A, Baa, Ba and B groups which Moody's believes
       possess the strongest investment attributes are designated by the
       symbols Aa1, A1, Baa1, Ba1 and B1.
 
 
                                      28
<PAGE>
 
INVESTMENT ADVISER 
Loomis, Sayles & Company, L.P. 
One Financial Center 
Boston, Massachusetts 02111
 
DISTRIBUTOR 
Loomis Sayles Distributors, L.P. 
One Financial Center 
Boston, Massachusetts 02111
 
TRANSFER AND DIVIDEND PAYING AGENT 
AND CUSTODIAN OF ASSETS 
State Street Bank and Trust Company 
Boston, Massachusetts 02102
 
SHAREHOLDER SERVICING AGENT FOR 
STATE STREET BANK AND TRUST COMPANY 
Boston Financial Data Services, Inc. 
P.O. Box 8314 
Boston, Massachusetts 02266
 
LEGAL COUNSEL 
Ropes & Gray 
One International Place 
Boston, Massachusetts 02110

INDEPENDENT ACCOUNTANTS
    
PricewaterhouseCoopers LLP     
One Post Office Square 
Boston, Massachusetts 02109 
<PAGE>
 
 
 One Financial Center . Boston, Massachusetts 02111 . (800) 633-3330
 
THE LOOMIS SAYLES FUNDS--FIXED INCOME FUNDS
 
 RETAIL CLASS SHARES OF:
 
   LOOMIS SAYLES BOND FUND
   LOOMIS SAYLES GLOBAL BOND FUND
        
   LOOMIS SAYLES INTERMEDIATE MATURITY BOND FUND
   LOOMIS SAYLES INVESTMENT GRADE BOND FUND
   LOOMIS SAYLES SHORT-TERM BOND FUND
<PAGE>
 
   
PROSPECTUS                                                 JANUARY 1, 1999     
 
THE LOOMIS SAYLES FUNDS--FIXED INCOME FUNDS
   
  Loomis Sayles Bond Fund, Loomis Sayles Global Bond Fund, Loomis Sayles In-
termediate Maturity Bond Fund, Loomis Sayles Investment Grade Bond Fund and
Loomis Sayles Short-Term Bond Fund (the "Funds" and each a "Fund"), each a se-
ries of Loomis Sayles Funds, are separately managed, no-load mutual funds,
each of which has its own investment objective and policies. Loomis, Sayles &
Company, L.P. ("Loomis Sayles") is the investment adviser of each Fund.     
   
  The Funds offer two classes of shares: a Retail Class that is described in
this Prospectus, and an Institutional Class, which generally has a higher min-
imum investment and bears lower expenses, that is described in a separate pro-
spectus. The Loomis Sayles Bond Fund also offers a third class of shares: an
Admin Class, bearing higher expenses than the Institutional or Retail Class,
that is described in a separate prospectus. This Prospectus concisely de-
scribes the information that an investor should know before investing in the
Retail Class shares of any Fund. Please read it carefully and keep it for fu-
ture reference. A Statement of Additional Information (SAI) dated January 1,
1999, as revised from time to time, is available free of charge; write to Loo-
mis Sayles Distributors, L.P. (the "Distributor"), One Financial Center, Bos-
ton, Massachusetts 02111 or telephone 800-633-3330. The SAI, which contains
more detailed information about the Funds, has been filed with the Securities
and Exchange Commission (the "SEC") and is available along with other related
materials on the SEC's Internet Website (http://www.sec.gov). The SAI is in-
corporated herein by reference (legally forms a part of the Prospectus). To
obtain more information about the Institutional Class or Admin Class of
shares, please call the Distributor toll-free at 800-633-3330, contact your
financial intermediary, or visit our Internet Website
(http://www.loomissayles.com).     
 
  For information about:                    For all other information about
   . Establishing an account                the Funds:
   . Account procedures and status          CALL 800-633-3330
   . Exchanges
   . Shareholder services
  CALL 800-626-9390
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS
A CRIMINAL OFFENSE.
       
                                       1
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>   
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
SUMMARY OF EXPENSES.......................................................   3
FINANCIAL HIGHLIGHTS......................................................   5
THE TRUST.................................................................  10
INVESTMENT OBJECTIVES AND POLICIES........................................  10
MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS AND RISK CONSIDERATIONS.....  14
THE FUNDS' INVESTMENT ADVISER.............................................  25
FUND EXPENSES.............................................................  26
PORTFOLIO TRANSACTIONS....................................................  28
HOW TO PURCHASE SHARES....................................................  28
SHAREHOLDER SERVICES......................................................  30
HOW TO REDEEM SHARES......................................................  31
CALCULATION OF PERFORMANCE INFORMATION....................................  33
DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES...........................  33
APPENDIX A
  DESCRIPTION OF BOND RATINGS.............................................  35
</TABLE>    
 
                                       2
<PAGE>
 
                              SUMMARY OF EXPENSES
               (FOR A RETAIL CLASS SHARE OF EACH INDICATED FUND)
   
  The following information is provided as an aid in understanding the various
expenses that an investor in a Fund will bear indirectly. The information
about each Fund shown below is based on expenses for the Funds' most recent
fiscal year, and should not be considered a representation of past or future
expenses, as actual expenses may be greater or less than those shown. Also,
the 5% annual return assumed in the Example should not be considered a
representation of investment performance, as actual performance will vary.
    
<TABLE>   
<CAPTION>
                                                                    INTERMEDIATE
                                               BOND      GLOBAL       MATURITY
                                               FUND     BOND FUND    BOND FUND
                                               ----     ---------   ------------
<S>                                            <C>      <C>         <C>
Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on Purchases
   (as % of offering price)..................  none       none          none
 Maximum Sales Load Imposed on Reinvested
   Dividends (as % of offering price)........  none       none          none
 Maximum Deferred Sales Load (as % of
   original purchase price or redemption
   proceeds).................................  none       none          none
 Redemption Fees/1......................../..  none       none          none
 Exchange Fees...............................  none       none          none
Annual Fund Operating Expenses
  (as a percentage of average net assets):
 Management Fees.............................   .60%       .60%          .40%
 12b-1 Fees..................................   .25%       .25%          .25%
 Other Operating Expenses (after expense
   reimbursements where indicated)...........   .15%/2/    .30%/2/       .15%/2/
 Total Fund Operating Expenses (after expense
   reimbursements where indicated)...........  1.00%/2/   1.15%/2/       .80%/2/
Example:
An investor would pay the following expenses
  on a $1,000 investment assuming a 5% annual
  return (with or without a redemption at the
  end of each time period):
 One Year....................................  $ 10       $ 12          $  8
 Three Years.................................  $ 32       $ 37          $ 26
 Five Years..................................  $ 55       $ 63          $ 44
 Ten Years...................................  $122       $140          $ 99
</TABLE>    
 
                                       3
<PAGE>
 
<TABLE>   
<CAPTION>
                                                       INVESTMENT
                                                         GRADE     SHORT-TERM
                                                       BOND FUND   BOND FUND
                                                       ----------  ----------
<S>                                                    <C>         <C>
Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on Purchases (as % of
  offering price).....................................    none        none
 Maximum Sales Load Imposed on Reinvested Dividends
  (as % of offering price)............................    none        none
 Maximum Deferred Sales Load (as % of original
  purchase price or redemption proceeds)..............    none        none
 Redemption Fees/1................................./..    none        none
 Exchange Fees........................................    none        none
Annual Fund Operating Expenses (as a percentage of
  average net assets):
 Management Fees......................................     .40%        .25%
 12b-1 Fees...........................................     .25%        .25%
 Other Operating Expenses (after expense
  reimbursements where indicated).....................     .15%/2/     .25%/2/
 Total Fund Operating Expenses (after expense
  reimbursements where indicated).....................     .80%/2/     .75%/2/
Example:
An investor would pay the following expenses on a
 $1,000 investment assuming a 5% annual return (with
 or
 without a redemption at the end of each time period):
 One Year.............................................    $  8        $  8
 Three Years..........................................    $ 26        $ 44
 Five Years...........................................    $ 44        $ 42
 Ten Years............................................    $ 99        $ 93
</TABLE>    
- -----------
   
/1/A $5 charge applies to any wire transfer of redemption proceeds from any
  Fund.     
       
   
/2/Loomis Sayles has voluntarily agreed, for an indefinite period, to limit
  the Funds' Total Operating Expenses to the percentages of average net assets
  shown in the table. Without this agreement, Other Operating Expenses
  (including 12b-1 fees) and Total Operating Expenses would have been 0.46%
  and 1.06%, respectively, for the Bond Fund, 1.18% and 1.78%, respectively,
  for the Global Bond Fund, 5.24% and 5.64%, respectively, for the
  Intermediate Maturity Bond Fund, 4.85% and 5.25%, respectively, for the
  Investment Grade Bond Fund, and 5.75% and 6.00%, respectively, for the
  Short-Term Bond Fund.     
 
                                       4
<PAGE>
 
                             FINANCIAL HIGHLIGHTS
 
               (FOR A RETAIL CLASS SHARE OF EACH INDICATED FUND
                 OUTSTANDING THROUGHOUT THE INDICATED PERIODS)
   
  The financial highlights that follow have been audited by
PricewaterhouseCoopers LLP, independent accountants. The information should be
read in conjunction with the financial highlights, financial statements and
the notes thereto contained in the Funds' 1998 Annual Report, which is
incorporated by reference in this Prospectus and the Statement of Additional
Information.     
 
<TABLE>   
<CAPTION>
                                                             BOND FUND
                                                       ------------------------
                                                        NINE MONTHS    JAN. 2**
                                                           ENDED          TO
                                                       SEPTEMBER 30*   DEC. 31,
                                                           1998          1997
                                                       -------------   --------
<S>                                                    <C>             <C>
Net asset value, beginning of period.................     $ 12.82      $ 12.38
                                                          -------      -------
Income from investment operations--
 Net investment income (loss)........................        0.66         0.84***
 Net realized and unrealized gain (loss)
  on investments.....................................       (0.77)        0.65
                                                          -------      -------
 Total from investment operations....................       (0.11)        1.49
                                                          -------      -------
Less distributions--
 Dividends from net investment income................       (0.42)       (0.83)
 Distributions from net realized capital gains.......        0.00        (0.22)
                                                          -------      -------
 Total distributions.................................       (0.42)       (1.05)
                                                          -------      -------
Net asset value, end of period.......................     $ 12.29      $ 12.82
                                                          =======      =======
Total return (%)****.................................        (1.1)+++     12.4
Net assets, end of period (000)......................     $53,908      $33,240
Ratio of operating expenses to average net
 assets (%)+.........................................        1.00++       1.00++
Ratio of net investment income to average net assets
 (%).................................................        7.13++       7.09++
Portfolio turnover rate (%)..........................          24+++        41
Without giving effect to voluntary expense
 limitations:
 The ratios of operating expenses to average net
  assets would have been (%).........................        1.06++       1.20++
 Net investment income per share would have been.....     $  0.66      $  0.82***
</TABLE>    
- -----------
   
   *The Fund's fiscal year-end changed to September 30 from December 31.     
   
  **Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
  + The adviser has agreed to reimburse a portion of the Fund's expenses
    during the period. Without this reimbursement, the Fund's ratio of
    operating expenses would have been higher.
 ++ Computed on an annualized basis.
    
+++ Periods less than one year are not annualized.     

                                       5
<PAGE>
 
<TABLE>   
<CAPTION>
                                                           GLOBAL BOND FUND
                                                        ----------------------
                                                            NINE
                                                           MONTHS     JAN. 2**
                                                            ENDED        TO
                                                        SEPTEMBER 30* DEC. 31,
                                                            1998        1997
                                                        ------------- --------
<S>                                                     <C>           <C>
Net asset value, beginning of period..................     $11.83      $12.35
                                                           ------      ------
Income from investment operations--
 Net investment income (loss).........................       0.44        0.63***
 Net realized and unrealized gain (loss)
  on investments......................................      (0.36)      (0.37)
                                                           ------      ------
 Total from investment operations.....................       0.08        0.26
                                                           ------      ------
Less distributions--
 Dividends from net investment income.................       0.00       (0.69)
 Distributions in excess of the net invetments
  income..............................................       0.00       (0.09)
                                                           ------      ------
 Total distributions..................................       0.00       (0.78)
                                                           ------      ------
Net asset value, end of period........................     $11.91      $11.83
                                                           ======      ======
Total return (%)****..................................        0.7+++      2.0
Net assets, end of period (000).......................     $6,376      $4,694
Ratio of operating expenses to average net
 assets (%)+..........................................       1.15++      1.15++
Ratio of net investment income to average net
 assets (%)...........................................       5.77++      5.60++
Portfolio turnover rate (%)...........................         28+++       75
Without giving effect to voluntary expense
 limitations:
The ratios of operating expenses to average net assets
 would have been (%)..................................       1.78++      2.44++
 Net investment income per share would have been......     $ 0.39      $ 0.49***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
  + The adviser has agreed to reimburse a portion of the Fund's expenses
    during the period. Without this reimbursement, the Fund's ratio of
    operating expenses would have been higher.
 ++ Computed on an annualized basis.
    
+++ Periods less than one year are not annualized.     
 
                                       6
<PAGE>
 
<TABLE>   
<CAPTION>
                                                           INTERMEDIATE
                                                             MATURITY
                                                            BOND FUND
                                                      ----------------------
                                                          NINE
                                                         MONTHS     JAN. 2**
                                                          ENDED        TO
                                                      SEPTEMBER 30* DEC. 31,
                                                          1998        1997
                                                      ------------- --------
<S>                                                   <C>           <C>
Net asset value, beginning of period................     $10.03     $ 10.00
                                                         ------     -------
Income from investment operations--
 Net investment income (loss).......................       0.49***     0.64 ***
 Net realized and unrealized gain (loss) on
  investments.......................................      (0.15)      (0.02)
                                                         ------     -------
 Total from investment operations...................       0.34        0.62
                                                         ------     -------
Less distributions--
 Dividends from net investment income...............      (0.31)      (0.54)
 Distributions in excess of net investment income...       0.00       (0.03)
 Distributions from net realized capital gains......       0.00       (0.02)
                                                         ------     -------
 Total distributions................................      (0.31)      (0.59)
                                                         ------     -------
Net asset value, end of period......................     $10.06     $ 10.03
                                                         ======     =======
Total return (%)****................................        3.4+++      6.2
Net assets, end of period (000).....................     $  663     $   423
Ratio of operating expenses to average net assets
 (%)+...............................................       0.80++      0.80 ++
Ratio of net investment income to average net assets
 (%)................................................       6.47++      6.13 ++
Portfolio turnover rate (%).........................         32+++      119
Without giving effect to voluntary expense
 limitations:
 The ratios of operating expenses to average net
  assets would have been (%)........................       5.64++   14.56++
 Net investment income per share would have been....     $ 0.12***  $(0.50)***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
  + The adviser has agreed to reimburse a portion of the Fund's expenses
    during the period. Without this reimbursement, the Fund's ratio of
    operating expenses would have been higher.
 ++ Computed on an annualized basis.
    
+++ Periods less than one year are not annualized.     

                                       7
<PAGE>
 
<TABLE>   
<CAPTION>
                                           INVESTMENT GRADE BOND FUND
                                           ---------------------------------
                                             NINE MONTHS        JAN. 2**
                                                ENDED              TO
                                            SEPTEMBER 30*       DEC. 31,
                                                1998              1997
                                           ---------------     -------------
<S>                                        <C>                 <C>
Net asset value, beginning of period.....     $       10.59     $       10.00
                                              -------------     -------------
Income from investment operations--
 Net investment income (loss)............              0.48              0.62***
 Net realized and unrealized gain (loss)
  on investments.........................             (0.49)             0.78
                                              -------------     -------------
 Total from investment operations........             (0.01)             1.40
                                              -------------     -------------
Less distributions--
 Dividends from net investment income....             (0.31)            (0.62)
 Distributions in excess of net
  investment income......................              0.00             (0.07)
 Distributions from net realized capital
  gains..................................              0.00             (0.12)
                                              -------------     -------------
 Total distributions.....................             (0.31)            (0.81)
                                              -------------     -------------
Net asset value, end of period...........     $       10.27     $       10.59
                                              =============     =============
Total return (%)****.....................              (0.2)+++          14.3
Net assets, end of period (000)..........     $       1,743     $         862
Ratio of operating expenses to average
 net assets (%)+.........................              0.80++            0.80++
Ratio of net investment income to average
 net assets (%)..........................              6.43++            6.51++
Portfolio turnover rate (%)..............                48+++            112
Without giving effect to voluntary
 expense limitations:
 The ratios of operating expenses to
  average net assets would have
  been (%)...............................              5.25++           10.95++
 Net investment income per share would
  have been..............................     $        0.15     $       (0.31)***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of the shares outstanding during the period.     
   
**** Total return would have been lower had the advisor not reduced its
     advisory fee and/or borne other operating expenses.     
  + The advisor has agreed to reimburse a portion of the Fund's expenses
    during the period. Without this reimbursement, the Fund's ratio of
    operating expenses would have been higher.
 ++ Computed on an annualized basis.
    
+++ Periods less than one year are not annualized.     

 
                                       8
<PAGE>
 
<TABLE>   
<CAPTION>
                                                           SHORT-TERM BOND FUND
                                                          ----------------------
                                                           NINE MONTHS  JAN. 2**
                                                              ENDED        TO
                                                          SEPTEMBER 30* DEC. 31,
                                                              1998        1997
                                                          ------------- --------
<S>                                                       <C>           <C>
Net asset value, beginning of period....................      $9.75      $ 9.70
                                                              -----      ------
Income from investment operations--
 Net investment income..................................       0.42        0.59
 Net realized and unrealized gain (loss)
  on investments........................................       0.21        0.06
                                                              -----      ------
 Total from investment operations.......................       0.63        0.65
                                                              -----      ------
Less distributions--
 Dividends from net investment income...................      (0.42)      (0.60)
                                                              -----      ------
 Total distributions....................................      (0.42)      (0.60)
                                                              -----      ------
Net asset value, end of period..........................      $9.96      $ 9.75
                                                              =====      ======
Total return (%)***.....................................        6.6++       6.9
Net assets, end of period (000).........................      $ 773      $  285
Ratio of operating expenses to average net
 assets (%)****.........................................       0.75+       0.75+
Ratio of net investment income to average net
 assets (%).............................................       5.66+       6.04+
Portfolio turnover rate (%).............................         47++        91
Without giving effect to voluntary expense limitations:
 The ratios of operating expenses to average net assets
  would have been (%)...................................       6.00+      17.77+
 Net investment income per share would have been........      $0.03      $(1.08)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
  + Computed on an annualized basis.
    
  ++ Periods less than one year are not annualized.     
 
NOTE: Further information about each Fund's performance is contained in the
      Funds' annual report to shareholders, which may be obtained without
      charge.
 
                                       9
<PAGE>
 
                                   THE TRUST
 
  Each Fund is a series of Loomis Sayles Funds (the "Trust"). The Trust is a
diversified open-end management investment company organized as a
Massachusetts business trust on February 20, 1991. The Trust is authorized to
issue an unlimited number of full and fractional shares of beneficial interest
in multiple series. Shares are freely transferable and entitle shareholders to
receive dividends as determined by the Trust's board of trustees and to cast a
vote for each share held at shareholder meetings. The Trust does not generally
hold shareholder meetings and will do so only when required by law.
Shareholders may call meetings to consider removal of the Trust's trustees.
 
                      INVESTMENT OBJECTIVES AND POLICIES
 
LOOMIS SAYLES BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
   
  The Fund seeks to achieve its objective by normally investing substantially
all of its assets in fixed income securities, although up to 20% of its total
assets may be invested in preferred stocks. At least 65% of the Fund's total
assets will normally be invested in bonds. The fixed income securities in
which the Fund may invest include corporate securities, securities issued or
guaranteed by the U.S. Government or its authorities, agencies or
instrumentalities ("U.S. Government Securities"), commercial paper, zero
coupon securities, mortgage-backed securities, stripped mortgage-backed
securities, collateralized mortgage obligations ("CMOs"), asset-backed
securities, when-issued securities, real estate investment trusts (REITs),
Rule 144A securities, repurchase agreements and convertible securities. The
Fund may engage in options and futures transactions, repurchase transactions,
foreign currency hedging transactions and swap transactions.     
   
  The Fund may invest any portion of its assets in securities of Canadian
issuers, and up to 20% of its total assets in securities of other foreign
issuers. The Fund may also invest up to 35% of its total assets in securities
of below investment grade quality (commonly known as "junk bonds"). Securities
of below investment grade quality are securities rated below the top four
rating categories by each major rating agency that has rated the security,
including securities in the lowest rating categories, and unrated securities
that Loomis Sayles determines to be of comparable quality.     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
                                      10
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
<S>                                                             <C>      <C>
AAA/Aaa........................................................     %        %
AA/Aa..........................................................     %        %
A/A............................................................     %        %
BBB/Baa........................................................     %        %
BB/Ba..........................................................     %        %
B/B............................................................     %        %
CCC/Caa........................................................     %        %
C/Ca...........................................................     %        %
D..............................................................     %      --
</TABLE>    
 
LOOMIS SAYLES GLOBAL BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of high current income and capital appreciation.
   
  The Fund seeks to achieve its objective by investing primarily in investment
grade fixed income securities denominated in various currencies, including
U.S. dollars, or in multicurrency units. Under normal conditions, the Fund
will invest at least 65% of its total assets in fixed income securities of
issuers from at least three countries, which may include the United States,
and no more than 40% of its total assets in issuers headquartered in any one
country. However, up to 100% of the Fund's total assets may be denominated in
U.S. dollars. The fund may also invest up to 20% of its total assets in
securities of below investment grade quality (commonly known as "junk bonds").
The fixed income securities in which the Fund may invest include corporate
securities, U.S. Government Securities, commercial paper, zero coupon
securities, mortgage-backed securities, CMOs, asset-backed securities, when-
issued securities, Rule 144A securities, repurchase agreements and convertible
securities. The Fund may engage in options and futures transactions,
repurchase transactions, foreign currency hedging transactions and swap
transactions.     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
   <S>                                                          <C>      <C>
   AAA/Aaa.....................................................     %        %
   AA/Aa.......................................................     %        %
   A/A.........................................................     %        %
   BBB/Baa.....................................................     %        %
   BB/Ba.......................................................     %        %
   B/B.........................................................     %        %
   CCC/Caa.....................................................   --       --
   C/Ca........................................................   --       --
   D...........................................................   --       --
</TABLE>    
 
                                      11
<PAGE>
 
       
LOOMIS SAYLES INTERMEDIATE MATURITY BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
   
  The Fund seeks to achieve its objective by normally investing at least 90%
of its total assets in fixed income securities of investment grade quality and
to maintain an average dollar weighted maturity of between three and ten
years. For purposes of the 90% test, a security will be treated as being of
investment grade quality if it is rated by at least one major rating agency in
one of its top four rating categories at the time of purchase or, if unrated,
is determined by Loomis Sayles to be of comparable quality. The Fund may also
invest up to 10% of its total assets in fixed income securities of below
investment grade quality (commonly known as "junk bonds"). The fixed income
securities in which the Fund may invest include corporate securities, U.S.
Government Securities, commercial paper, zero coupon securities, mortgage-
backed securities, CMOs, asset-backed securities, when-issued securities,
REITs, Rule 144A securities, repurchase agreements and convertible securities.
The Fund may engage in options and futures transactions, repurchase
transactions, foreign currency hedging transactions, swap transactions, and
securities lending. The Fund may invest any portion of its assets in
securities of Canadian issuers and up to 20% of its assets in securities of
other foreign issuers.     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
<S>                                                             <C>      <C>
AAA/Aaa........................................................     %        %
AA/Aa..........................................................   --       --
A/A............................................................   --       --
BBB/Baa........................................................     %        %
BB/Ba..........................................................     %        %
B/B............................................................     %        %
CCC/Caa........................................................   --       --
C/Ca...........................................................   --       --
D..............................................................   --       --
</TABLE>    
 
LOOMIS SAYLES INVESTMENT GRADE BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
 
  The Fund seeks to achieve its objective by normally investing at least 65%
of its total assets in fixed income securities of investment grade quality. Up
to
 
                                      12
<PAGE>
 
   
20% of the Fund's total assets may be invested in preferred stocks. The Fund
may also invest up to 10% of its total assets in fixed income securities of
below investment grade quality (commonly known as "junk bonds"). The fixed
income securities in which the Fund may invest include corporate securities,
U.S. Government Securities, commercial paper, zero coupon securities,
mortgage-backed securities, CMOs, asset-backed securities, when-issued
securities, REITs, Rule 144A securities, repurchase agreements and convertible
securities. The Fund may engage in options and futures transactions,
repurchase transactions, foreign currency hedging transactions, swap
transactions and securities lending. The Fund may invest any portion of its
assets in securities of Canadian issuers and up to 20% of its assets in the
securities of other foreign issuers.     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
<S>                                                             <C>      <C>
AAA/Aaa........................................................     %        %
AA/Aa..........................................................     %        %
A/A............................................................     %        %
BBB/Baa........................................................     %        %
BB/Ba..........................................................     %        %
B/B............................................................     %        %
CCC/Caa........................................................     %      --
C/Ca...........................................................   --       --
D..............................................................   --       --
</TABLE>    
 
LOOMIS SAYLES SHORT-TERM BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation with relatively low
fluctuation in net asset value.
   
  The Fund seeks to achieve its objective by normally investing substantially
all of its assets in fixed income securities, although up to 20% of its total
assets may be invested in non-convertible preferred stock. At least 65% of the
Fund's total assets will normally be invested in bonds with a remaining
maturity of 5 years or less. The Fund may invest up to 20% of its total assets
in securities of foreign issuers. The Fund may also invest up to 20% of its
total assets in securities of below investment grade quality (commonly known
as "junk bonds"). The fixed income securities in which the Fund may invest
include corporate securities, U.S. Government Securities, commercial paper,
zero coupon securities, mortgage-backed securities, CMOs, asset-backed
securities,     
 
                                      13
<PAGE>
 
   
when-issued securities, REITs, Rule 144A securities, repurchase agreements and
convertible securities. The Fund may engage in options and futures
transactions, repurchase transactions, foreign currency hedging transactions
and swap transactions.     
 
  In an effort to minimize fluctuations in market value, the Fund is expected
to maintain an average dollar-weighted maturity of between one and three
years.
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
<S>                                                             <C>      <C>
AAA/Aaa........................................................     %        %
AA/Aa..........................................................   --       --
A/A............................................................     %        %
BBB/Baa........................................................     %        %
BB/Ba..........................................................     %        %
B/B............................................................     %        %
CCC/Caa........................................................   --       --
C/Ca...........................................................   --       --
D..............................................................   --       --
</TABLE>    
 
ALL FUNDS
 
  For temporary defensive purposes, each Fund may invest any portion of its
assets in fixed income securities, cash or any other securities deemed
appropriate by Loomis Sayles.
 
  Except for each Fund's investment objective, and any investment policies
that are identified as "fundamental," all of the investment policies of each
Fund may be changed without a vote of Fund shareholders.
 
                 MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS
                            AND RISK CONSIDERATIONS
 
DEBT AND OTHER FIXED INCOME SECURITIES
 
  Each of the Funds may invest in fixed income securities of any maturity,
although the Short-Term Bond Fund expects to maintain an average dollar
weighted maturity of less than three years, and the Intermediate Maturity Bond
Fund expects to maintain an average dollar weighted maturity of between three
and ten years. Fixed income securities pay a specified rate of interest or
dividends, or a rate that is adjusted periodically by reference to some
specified
 
                                      14
<PAGE>
 
index or market rate. Fixed income securities include securities issued by
federal, state, local and foreign governments and related agencies, and by a
wide range of private issuers. Because interest rates vary, it is impossible
to predict the income of a Fund that invests in fixed income securities for
any particular period. The net asset value of such a Fund's shares will vary
as a result of changes in the value of the securities in the Fund's portfolio.
 
  Fixed income securities are subject to market and credit risk. Market risk
relates to changes in a security's value as a result of changes in interest
rates generally. In general, the values of fixed income securities increase
when prevailing interest rates fall and decrease when interest rates rise.
Credit risk relates to the ability of the issuer to make payments of principal
and interest.
 
U.S. GOVERNMENT SECURITIES
 
  U.S. Government Securities have different kinds of government support. For
example, some U.S. Government Securities, such as U.S. Treasury bonds, are
supported by the full faith and credit of the United States, whereas certain
other U.S. Government Securities issued or guaranteed by federal agencies or
government-sponsored enterprises are not supported by the full faith and
credit of the United States.
 
  Although U.S. Government Securities generally do not involve the credit
risks associated with other types of fixed income securities, the market
values of U.S. Government Securities do go up and down as interest rates
change. Thus, for example, the value of an investment in a Fund that holds
U.S. Government Securities may fall during times of rising interest rates.
Yields on U.S. Government Securities tend to be lower than those on corporate
securities of comparable maturities.
 
  Some U.S. Government Securities, such as Government National Mortgage
Association Certificates ("GNMA"), are known as "mortgage-backed" securities.
Interest and principal payments on the mortgages underlying mortgage-backed
U.S. Government Securities are passed through to the holders of the security.
If a Fund purchases mortgage-backed securities at a discount or a premium, the
Fund will recognize a gain or loss when the payments of principal, through
prepayment or otherwise, are passed through to the Fund and, if the payment
occurs in a period of falling interest rates, the Fund may not be able to
reinvest the payment at as favorable an interest rate. As a result of these
principal prepayment features, mortgage-backed securities are generally more
volatile investments than many other fixed income securities.
 
  In addition to investing directly in U.S. Government Securities, the Funds
may purchase certificates of accrual or similar instruments ("strips")
evidencing undivided ownership interests in interest payments or principal
 
                                      15
<PAGE>
 
payments, or both, in U.S. Government Securities. These investment instruments
may be highly volatile.
 
LOWER RATED FIXED INCOME SECURITIES
   
  Each Fund may invest a portion of its total assets in securities rated below
investment grade (commonly referred to as "junk bonds"). The Bond Fund may
invest up to 35%, the Global Bond and Short-Term Bond Funds each may invest up
to 20%, the Investment Grade Bond and Intermediate Maturity Bond Funds each
may invest up to 10% of its total assets in such securities. For purposes of
the foregoing percentages, a security will be treated as being of investment
grade quality if at the time a Fund acquires it at least one major rating
agency has rated the security in its top four rating categories (even if
another such agency has issued a lower rating), or if the security is unrated
but Loomis Sayles determines it to be of investment grade quality. Lower rated
fixed income securities generally provide higher yields, but are subject to
greater credit and market risk, than higher quality fixed income securities.
Lower rated fixed income securities are considered predominantly speculative
with respect to the ability of the issuer to meet principal and interest
payments. Achievement of the investment objective of a Fund investing in lower
rated fixed income securities may be more dependent on Loomis Sayles' own
credit analysis than is the case with higher quality bonds. The market for
lower rated fixed income securities may be more severely affected than some
other financial markets by economic recession or substantial interest rate
increases, by changing public perceptions of this market or by legislation
that limits the ability of certain categories of financial institutions to
invest in these securities. In addition, the secondary market may be less
liquid for lower rated fixed income securities. This lack of liquidity at
certain times may affect the values of these securities and may make the
valuation and sale of these securities more difficult. Securities in the
lowest rating categories may be in poor standing or in default. Securities in
the lowest investment grade category (BBB or Baa) have some speculative
characteristics.     
 
  For more information about the ratings services' descriptions of the various
rating categories, see Appendix A.
 
COMMON STOCKS AND OTHER EQUITY SECURITIES
 
  Common stocks and similar equity securities, such as warrants and
convertibles, are volatile and more risky than some other forms of investment.
The value of an investment in a Fund that invests in equity securities may
sometimes decrease. Equity securities of companies with relatively small
market capitalization may be more volatile than the securities of larger, more
established companies and than the broad equity market indexes.
 
                                      16
<PAGE>
 
ZERO COUPON SECURITIES
 
  Each Fund may invest in "zero coupon" fixed income securities. These
securities accrue interest at a specified rate, but do not pay interest in
cash on a current basis. A Fund investing in zero coupon securities is
required to distribute the income on these securities to Fund shareholders as
the income accrues, even though the Fund is not receiving the income in cash
on a current basis. Thus the Fund may have to sell other investments to obtain
cash to make income distributions at times when Loomis Sayles would not
otherwise deem it advisable to do so. The market value of zero coupon
securities is often more volatile than that of non-zero coupon fixed income
securities of comparable quality and maturity.
 
MORTGAGE-BACKED SECURITIES
   
  Each Fund may invest in mortgage-backed securities, such as GNMA or Fannie
Mae certificates, which differ from traditional debt securities. Among the
major differences are that interest and principal payments are made more
frequently, usually monthly, and that principal may be prepaid at any time
because the underlying mortgage loans generally may be prepaid at any time. As
a result, if a Fund purchases these assets at a premium, a faster-than-
expected prepayment rate will reduce yield to maturity, and a slower-than-
expected prepayment rate will increase yield to maturity. If a Fund purchases
mortgage-backed securities at a discount, faster-than-expected prepayments
will increase, and slower-than-expected prepayments will reduce, yield to
maturity. Prepayments, and resulting amounts available for reinvestment by the
Fund, are likely to be greater during period of declining interest rates and,
as a result, are likely to be reinvested at lower interest rates. Accelerated
prepayments on securities purchased at a premium may result in a loss of
principal if the premium has not been fully amortized at the time of
prepayment. Although these securities will decrease in value as a result of
increases in interest rates generally, they are likely to appreciate less than
other fixed-income securities when interest rates decline because of the risk
of prepayments.     
 
STRIPPED MORTGAGE-BACKED SECURITIES
 
  Each Fund may invest in interest-only and principal-only classes of
mortgage-backed securities ("IOs" and "POs"). The yield to maturity on an IO
or PO is extremely sensitive not only to changes in prevailing interest rates
but also to the rate of principal payments (including prepayments) on the
underlying assets. A rapid rate of principal prepayments may have a measurably
adverse effect on a Fund's yield to maturity to the extent it invests in IOs.
If the assets underlying the IOs experience greater than anticipated
prepayments of principal, the Fund may fail to recoup fully its initial
investment in these securities. Conversely, POs tend to increase in value if
prepayments are greater than anticipated and decline if prepayments are slower
than anticipated.
 
                                      17
<PAGE>
 
  The secondary market for stripped mortgage-backed securities may be more
volatile and less liquid than that for other mortgage-backed securities,
potentially limiting a Fund's ability to buy or sell those securities at any
particular time.
 
COLLATERALIZED MORTGAGE OBLIGATIONS
 
  Each Fund may invest in CMOs. A CMO is a security backed by a portfolio of
mortgages or mortgage-backed securities held under an indenture. CMOs may be
issued either by U.S. Government instrumentalities or by non-governmental
entities. The issuer's obligation to make interest and principal payments is
secured by the underlying portfolio of mortgages or mortgage-backed
securities. CMOs are issued with a number of classes or series which have
different maturities and which may represent interests in some or all of the
interest or principal on the underlying collateral or a combination thereof.
CMOs of different classes are generally retired in sequence as the underlying
mortgage loans in the mortgage pool are repaid. In the event of sufficient
early prepayments on such mortgages, the class or series of CMOs first to
mature generally will be retired prior to its maturity. As with other
mortgage-backed securities, the early retirement of a particular class or
series of CMOs held by a Fund could involve the loss of any premium the Fund
paid when it acquired the investment and could result in the Fund's
reinvesting the proceeds at a lower interest rate than the retired CMO paid.
Because of the early retirement feature, CMOs may be more volatile than many
other fixed-income investments.
 
ASSET-BACKED SECURITIES
 
  Each Fund may invest in asset-backed securities. Through the use of trusts
and special purpose corporations, automobile and credit card receivables are
securitized in pass-through structures similar to mortgage pass-through
structures or in a pass-through structure similar to the CMO structure.
Generally, the issuers of asset-backed bonds, notes or pass-through
certificates are special purpose entities and do not have any significant
assets other than the receivables securing such obligations. In general, the
collateral supporting asset-backed securities is of shorter maturity than
mortgage loans. Instruments backed by pools of receivables are similar to
mortgage-backed securities in that they are subject to unscheduled prepayments
of principal prior to maturity. When the obligations are prepaid, the Fund
will ordinarily reinvest the prepaid amounts in securities the yields of which
reflect interest rates prevailing at the time. Therefore, a Fund's ability to
maintain a portfolio that includes high-yielding asset-backed securities will
be adversely affected to the extent that prepayments of principal must be
reinvested in securities that have lower yields than the prepaid obligations.
Moreover, prepayments of securities purchased at a premium could result in a
realized loss.
 
                                      18
<PAGE>
 
WHEN-ISSUED SECURITIES
 
  Each Fund may purchase securities on a "when-issued" basis. This means that
the Fund will enter into a commitment to buy the security before the security
has been issued. The Fund's payment obligation and the interest rate on the
security are determined when the Fund enters into the commitment. The security
is typically delivered to the Fund 15 to 120 days later. No interest accrues
on the security between the time the Fund enters into the commitment and the
time the security is delivered. If the value of the security being purchased
falls between the time a Fund commits to buy it and the payment date, the Fund
may sustain a loss. The risk of this loss is in addition to the Fund's risk of
loss on the securities actually in its portfolio at the time. In addition,
when the Fund buys a security on a when-issued basis, it is subject to the
risk that market rates of interest will increase before the time the security
is delivered, with the result that the yield on the security delivered to the
Fund may be lower than the yield available on other, comparable securities at
the time of delivery. If a Fund has outstanding obligations to buy when-issued
securities, it will maintain liquid assets in a segregated account at its
custodian bank in an amount sufficient to satisfy these obligations.
   
CONVERTIBLE SECURITIES     
   
  Convertible securities include corporate bonds, notes or preferred stocks of
U.S. or foreign issuers that can be converted into (that is, exchanged for)
common stocks or other equity securities at a stated price or rate.
Convertible securities also include other securities, such as warrants, that
provide an opportunity for equity participation. Because convertible
securities can be converted into equity securities, their value will normally
vary in some proportion with those of the underlying equity securities.
Convertible securities usually provide a higher yield than the underlying
equity security, however, so that when the price of the underlying equity
security falls, the decline in the price of the convertible security may
sometimes be less substantial than that of the underlying equity security. Due
to the conversion feature, convertible securities generally yield less than
nonconvertible fixed income securities of similar credit quality and maturity.
The Fund's investment in convertible securities may at times include
securities that have a mandatory conversion feature, pursuant to which the
securities convert automatically into common stock at a specified date and
conversion ratio, or that are convertible at the option of the issuer. Because
conversion is not at the option of the holder, the Fund may be required to
convert the security into the underlying common stock even at times when the
value of the underlying common stock has declined substantially.     
   
REAL ESTATE INVESTMENT TRUSTS     
   
  Each Fund may invest in REITs. REITs involve certain unique risks in
addition to those risks associated with investing in the real estate industry
in     
 
                                      19
<PAGE>
 
   
general (such as possible declines in the value of real estate, lack of
availability of mortgage funds or extended vacancies of property). Equity
REITs may be affected by changes in the value of the underlying property owned
by the REITs, while mortgage REITs may be affected by the quality of any
credit extended. REITs are dependent upon management skills, are not
diversified, are subject to heavy cash flow dependency, risks of default by
borrowers and self-liquidation. REITs are also subject to the possibilities of
failing to qualify for tax-free pass-through of income under the Code, and
failing to maintain their exemptions from registration under the Investment
Company Act of 1940 (the "1940 Act").     
   
  Investment in REITs involves risk similar to those associated with investing
in small capitalization companies. REITs may have limited financial resources,
may trade less frequently and in a limited volume and may be subject to more
abrupt or erratic price movements than larger securities.     
 
RULE 144A SECURITIES
 
  Each Fund may invest in Rule 144A securities, which are privately offered
securities that can be resold only to certain qualified institutional buyers.
Rule 144A securities are treated as illiquid, unless Loomis Sayles has
determined, under guidelines established by the Trust's trustees, that the
particular issue of Rule 144A securities is liquid.
 
FOREIGN SECURITIES
   
  Each Fund may invest in securities of issuers organized or headquartered
outside the United States ("foreign securities"). The Short-Term Bond Fund
will not purchase a foreign security if, as a result, the Fund's holdings of
foreign securities would exceed 20% of the Fund's total assets. The Bond,
Intermediate Maturity Bond and Investment Grade Bond Funds may each invest any
portion of its assets in securities of Canadian issuers, but will not purchase
foreign securities other than those of Canadian issuers if, as a result, such
Fund's holdings of non-U.S. and non-Canadian securities would exceed 20% of
the Fund's total assets.     
 
  Although investing in foreign securities may increase a Fund's
diversification and reduce portfolio volatility, foreign securities may
present risks not associated with investments in comparable securities of U.S.
issuers. There may be less information publicly available about a foreign
corporate or government issuer than about a U.S. issuer, and foreign corporate
issuers are not generally subject to accounting, auditing and financial
reporting standards and practices comparable to those in the United States.
The securities of some foreign issuers are less liquid and at times more
volatile than securities of comparable U.S. issuers. Foreign brokerage
commissions and securities custody costs are often higher than in the United
States. With respect to certain foreign
 
                                      20
<PAGE>
 
countries, there is a possibility of governmental expropriation of assets,
confiscatory taxation, political or financial instability and diplomatic
developments that could affect the value of investments in those countries. A
Fund's receipt of interest on foreign government securities may depend on the
availability of tax or other revenues to satisfy the issuer's obligations.
 
  A Fund's investments in foreign securities may include investments in
countries whose economies or securities markets are not yet highly developed.
Special considerations associated with these investments (in addition to the
considerations regarding foreign investments generally) may include, among
others, greater political uncertainties, an economy's dependence on revenues
from particular commodities or on international aid or development assistance,
currency transfer restrictions, highly limited numbers of potential buyers for
such securities and delays and disruptions in securities settlement
procedures.
 
  Since most foreign securities are denominated in foreign currencies or
traded primarily in securities markets in which settlements are made in
foreign currencies, the value of these investments and the net investment
income available for distribution to shareholders of a Fund investing in these
securities may be affected favorably or unfavorably by changes in currency
exchange rates, exchange control regulations or foreign withholding taxes.
Changes in the value relative to the U.S. dollar of a foreign currency in
which a Fund's holdings are denominated will result in a change in the U.S.
dollar value of the Fund's assets and the Fund's income available for
distribution.
 
  In addition, although part of a Fund's income may be received or realized in
foreign currencies, the Fund will be required to compute and distribute its
income in U.S. dollars. Therefore, if the value of a currency relative to the
U.S. dollar declines after the Fund's income has been earned in that currency,
translated into U.S. dollars and declared as a dividend, but before payment of
the dividend, the Fund could be required to liquidate portfolio securities to
pay the dividend. Similarly, if the value of a currency relative to the U.S.
dollar declines between the time the Fund accrues expenses in U.S. dollars and
the time such expenses are paid, the amount of such currency required to be
converted into U.S. dollars will be greater than the equivalent amount in such
currency of such expenses at the time they were incurred.
 
  In determining whether to invest assets of the Funds in securities of a
particular foreign issuer, Loomis Sayles will consider the likely effects of
foreign taxes on the net yield available to the Fund and its shareholders.
Compliance with foreign tax law may reduce a Fund's net income available for
distribution to shareholders.
 
                                      21
<PAGE>
 
FOREIGN CURRENCY HEDGING TRANSACTIONS
 
  The Funds may engage in foreign currency exchange transactions to protect
the value of specific portfolio positions or in anticipation of changes in
relative values of currencies in which current or future Fund portfolio
holdings are denominated or quoted. For example, to protect against a change
in the foreign currency exchange rate between the date on which a Fund
contracts to purchase or sell a security and the settlement date for the
purchase or sale, or to "lock in" the equivalent of a dividend or interest
payment in another currency, a Fund might purchase or sell a foreign currency
on a spot (that is, cash) basis at the prevailing spot rate. If conditions
warrant, the Funds may also enter into private contracts to purchase or sell
foreign currencies at a future date ("forward contracts"). The Funds might
also purchase exchange-listed and over-the-counter call and put options on
foreign currencies. Over-the-counter currency options are generally less
liquid than exchange-listed options, and will be treated as illiquid assets.
The Funds may not be able to dispose of over-the-counter options readily.
 
  Foreign currency transactions involve costs and may result in losses.
 
SWAP TRANSACTIONS
 
  The Funds may enter into interest rate or currency swaps. The Funds will
enter into these transactions primarily to preserve a return or spread on a
particular investment or portion of its portfolio, to protect against currency
fluctuations, as a duration management technique or to protect against any
increase in the price of securities a Fund anticipates purchasing at a later
date. Interest rate swaps involve the exchange by a Fund with another party of
their respective commitments to pay or receive interest (for example, an
exchange of floating rate payments for fixed rate payments with respect to a
notional amount of principal). A currency swap is an agreement to exchange
cash flows on a notional amount based on changes in the relative values of the
specified currencies. The Fund will maintain liquid assets in a segregated
custodial account to cover its current obligations under swap agreements.
Because swap agreements are not exchange-traded, but are private contracts
into which the Fund and a swap counter party enter as principals, the Fund may
experience a loss or delay in recovering assets if the counterparty were to
default on its obligations.
 
OPTIONS AND FUTURES TRANSACTIONS
 
  The Funds may buy, sell or write options on securities, securities indexes,
currencies or futures contracts and may buy and sell futures contracts on
securities, securities indexes or currencies. The Funds may engage in these
transactions either for the purpose of enhancing investment return, or to
hedge
 
                                      22
<PAGE>
 
against changes in the value of other assets that the Funds own or intend to
acquire. Options and futures fall into the broad category of financial
instruments known as "derivatives" and involve special risks. Use of options
or futures for other than hedging purposes may be considered a speculative
activity, involving greater risks than are involved in hedging.
 
  Options can generally be classified as either "call" or "put" options. There
are two parties to a typical options transaction: the "writer" and the
"buyer." A call option gives the buyer the right to buy a security or other
asset (such as an amount of currency or a futures contract) from, and a put
option gives the buyer the right to sell a security or other asset to, the
option writer at a specified price, on or before a specified date. The buyer
of an option pays a premium when purchasing the option, which reduces the
return on the underlying security or other asset if the option is exercised,
and results in a loss if the option expires unexercised. The writer of an
option receives a premium from writing an option, which may increase its
return if the option expires or is closed out at a profit. If a Fund as the
writer of an option is unable to close out an unexpired option, it must
continue to hold the underlying security or other asset until the option
expires, to "cover" its obligation under the option.
 
  A futures contract creates an obligation by the seller to deliver and the
buyer to take delivery of the type of instrument or cash at the time and in
the amount specified in the contract. Although many futures contracts call for
the delivery (or acceptance) of the specified instrument, futures are usually
closed out before the settlement date through the purchase (or sale) of a
comparable contract. If the price of the sale of the futures contract by a
Fund exceeds (or is less than) the price of the offsetting purchase, the Fund
will realize a gain (or loss).
 
  The value of options purchased by a Fund and futures contracts held by a
Fund may fluctuate based on a variety of market and economic factors. In some
cases, the fluctuations may offset (or be offset by) changes in the value of
securities held in a Fund's portfolio. All transactions in options and futures
involve the possible risk of loss to the Fund of all or a significant part of
the value of its investment. In some cases, the risk of loss may exceed the
amount of the Fund's investment. When a Fund writes a call option or sells a
futures contract without holding the underlying securities, currencies or
futures contracts, its potential loss is unlimited. The Fund will be required,
however, to set aside with its custodian bank liquid assets in amounts
sufficient at all times to satisfy its obligations under options and futures
contracts.
 
  The successful use of options and futures will usually depend on Loomis
Sayles' ability to forecast stock market, currency or other financial market
movements correctly. The Fund's ability to hedge against adverse changes in
the value of securities held in its portfolio through options and futures also
depends on the degree of correlation between changes in the value of futures
or options positions and changes in the values of the portfolio securities.
The successful
 
                                      23
<PAGE>
 
use of futures and exchange traded options also depends on the availability of
a liquid secondary market to enable a Fund to close its positions on a timely
basis. There can be no assurance that such a market will exist at any
particular time. In the case of options that are not traded on an exchange
("over-the-counter" options), a Fund is at risk that the other party to the
transaction will default on its obligations, or will not permit a Fund to
terminate the transaction before its scheduled maturity. As a result of these
characteristics, each Fund will treat most over-the-counter options (and the
assets it segregates to cover its obligations thereunder) as illiquid.
 
  The options and futures markets of foreign countries are small compared to
those of the United States and consequently are characterized in most cases by
less liquidity than are the U.S. markets. In addition, foreign markets may be
subject to less detailed reporting requirements and regulatory controls than
U.S. markets. Furthermore, investments in options in foreign markets are
subject to many of the same risks as other foreign investments. See "Foreign
Securities" above.
 
REPURCHASE AGREEMENTS
 
  Each Fund may invest in repurchase agreements. In repurchase agreements, a
Fund buys securities from a seller, usually a bank or brokerage firm, with the
understanding that the seller will repurchase the securities at a higher price
at a later date. Such transactions afford an opportunity for a Fund to earn a
return on available cash at minimal market risk, although the Fund may be
subject to various delays and risks of loss if the seller is unable to meet
its obligations to repurchase.
 
SECURITIES LENDING
 
  The Intermediate Maturity Bond and Investment Grade Bond Funds may lend
their portfolio securities to broker-dealers or other parties under contracts
calling for the deposit by the borrower with the Fund's custodian of cash
collateral equal to at least the market value of the securities loaned, marked
to market on a daily basis. The Fund will continue to benefit from interest or
dividends on the securities loaned and will also receive interest through
investment of the cash collateral in short-term liquid investments. No loans
will be made if, as a result, the aggregate amount of such loans outstanding
at any time would exceed 33 1/3% of the Fund's total assets (taken at current
value). Any voting rights, or rights to consent, relating to securities loaned
pass to the borrower. However, if a material event affecting the investment
occurs, such loans will be called so that the securities may be voted by the
Fund. The Fund pays various fees in connection with such loans, including
shipping fees and reasonable custodial or placement fees.
 
                                      24
<PAGE>
 
  Securities loans must be fully collateralized at all times, but involve some
credit risk to the Fund if the borrower defaults on its obligation and the
Fund is delayed or prevented from recovering the collateral.
 
YEAR 2000
 
  Many computer software systems in use today cannot properly process date-
related information from and after January 1, 2000. Should any of the computer
systems employed by the Funds' major service providers fail to process this
type of information properly, that could have a negative impact on the Funds'
operations and the services that are provided to the Funds' shareholders.
Loomis Sayles and the Distributor have each advised the Funds that they are
reviewing all of their computer systems with the goal of modifying or
replacing such systems prior to January 1, 2000, to the extent necessary to
foreclose any such negative impact. In addition, Loomis Sayles has been
advised by the Funds' custodian that it is also in the process of reviewing
its systems with the same goal. As of the date of this prospectus, the Funds
and Loomis Sayles have no reason to believe that these goals will not be
achieved. Similarly, the values of certain of the portfolio securities held by
the Funds may be adversely affected by the inability of the securities'
issuers or of third parties to process this type of information properly.
 
                         THE FUNDS' INVESTMENT ADVISER
 
  The Funds' investment adviser is Loomis Sayles, One Financial Center,
Boston, Massachusetts 02111. Founded in 1926, Loomis Sayles is one of the
country's oldest and largest investment firms. The general partner of Loomis
Sayles is a special purpose corporation that is an indirect wholly-owned
subsidiary of Nvest Companies, L.P. ("Nvest Companies"). Nvest Companies'
managing general partner, Nvest Corporation, is a direct wholly-owned
subsidiary of Metropolitan Life Insurance Company ("Met Life"), a mutual life
insurance company. Nvest Companies' advising general partner, Nvest, L.P., is
a publicly traded company listed on the New York Stock Exchange. Nvest
Corporation is the sole general partner of Nvest L.P.
 
  In addition to selecting and reviewing the Funds' investments, Loomis Sayles
provides executive and other personnel for the management of the Funds. The
Funds' board of trustees supervises Loomis Sayles' conduct of the affairs of
the Funds.
       
       
   
  As of October 31, 1998, Charles Schwab & Co. Inc. owned 48%, 40%, 55%, 27%,
and 21% of the Bond Fund, Global Bond Fund, Intermediate Maturity Bond Fund,
Investment Grade Bond Fund and Short-Term Bond Fund, respectively. As of
October 31, 1998, Fleet National Bank, Norwest Bank and     
 
                                      25
<PAGE>
 
   
San Diego Transit Pension Plan owned 13%, 16%, and 8% of the Global Bond Fund,
respectively. As of October 31, 1998, Hawaii Sheet Metal Workers Health &
Welfare Fund and Pomona College owned 26% and 7% of the Intermediate Maturity
Bond Fund, respectively. As of October 31, 1998, Loomis Sayles & Company, L.P.
owned 26% of the Investment Grade Bond Fund, respectively. As of October 31,
1998, John W. George, Jr. Trust, NFSC, and PAMCAH-UA Local 675 owned 6%, 14%,
and 8% of the Short-Term Bond Fund, respectively. Shareholders holding more
than 25% of a Fund's shares may be deemed to control the relevant Fund.     
   
  Daniel J. Fuss, President of the Trust and Executive Vice President of
Loomis Sayles, has served as the portfolio manager of the Bond Fund since its
commencement of investment operations in 1991 and as the portfolio manager of
the Investment Grade Bond Fund since its commencement of investment operations
in 1997. Kathleen C. Gaffney, Vice President of the Trust and Loomis Sayles,
has served as associate portfolio manager of the Bond Fund since October 1997.
E. John deBeer, Vice President of the Trust and of Loomis Sayles, has served
as the portfolio manager of the Global Bond Fund since its commencement of
investment operations in 1991. Anthony J. Wilkins, Vice President of the Trust
and of Loomis Sayles, has served as the portfolio manager of the Intermediate
Maturity Bond Fund since its commencement of investment operations in 1997.
John Hyll, Vice President of the Trust and of Loomis Sayles, has served as the
portfolio manager of the Short-Term Bond Fund since its commencement of
investment operations in 1992. Curt A. Mitchell, Vice President of Loomis
Sayles, has served as a portfolio manager of the Short-Term Bond Fund since
October 1998. Each of the foregoing, except Mr. Mitchell, has been employed by
Loomis Sayles for at least five years. Before joining Loomis Sayles in 1995,
Mr. Mitchell was a portfolio manager at Firstar Investment & Management
Company.     
 
                                 FUND EXPENSES
 
  Each Fund pays Loomis Sayles a monthly investment advisory fee at the
following annual percentage rates of the Fund's average daily net assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                    RATE
   ----                                                                    ----
   <S>                                                                     <C>
   Bond................................................................... .60%
   Global Bond............................................................ .60%
   Intermediate Maturity Bond............................................. .40%
   Investment Grade Bond.................................................. .40%
   Short-Term Bond........................................................ .25%
</TABLE>    
 
  In addition to the investment advisory fee, each Fund pays all expenses not
expressly assumed by Loomis Sayles, including taxes, brokerage commissions,
 
                                      26
<PAGE>
 
fees and expenses of registering or qualifying the Fund's shares under federal
and state securities laws, fees of the Fund's custodian, transfer agent,
independent accountants and legal counsel, expenses of shareholders' and
trustees' meetings, expenses of preparing, printing and mailing prospectuses
to existing shareholders and fees of trustees who are not directors, officers
or employees of Loomis Sayles or its affiliated companies.
 
  Loomis Sayles has voluntarily agreed, for an indefinite period, to reduce
its advisory fees and/or bear other Fund expenses to the extent necessary to
limit Fund total annual operating expenses of the Retail Class of shares of
each Fund to the following annual percentage rate of the Fund's average net
assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                    RATE
   ----                                                                    ----
   <S>                                                                     <C>
   Bond................................................................... 1.00%
   Global Bond............................................................ 1.15%
   Intermediate Maturity Bond.............................................  .80%
   Investment Grade Bond..................................................  .80%
   Short-Term Bond........................................................  .75%
</TABLE>    
 
  Loomis Sayles may change or terminate these voluntary arrangements at any
time, but the Funds' Prospectus would be supplemented to describe the change.
 
  Under a Distribution Plan adopted pursuant to Rule 12b-1 under the 1940 Act,
each of the Funds pays the Distributor, a subsidiary of Loomis Sayles, a
monthly distribution fee at an annual rate not to exceed 0.25% of the Fund's
average net assets attributable to the Retail Class shares. The Distributor
may pay all or any portion of the distribution fee to securities dealers or
other organizations (including, but not limited to, any affiliate of the
Distributor) as commissions, asset-based sales charges or other compensation
with respect to the sale of Retail Class shares of the Funds, or for providing
personal services to investors in Retail Class shares of the Funds and/or the
maintenance of accounts, and may retain all or any portion of the distribution
fee as compensation for the Distributor's services as principal underwriter of
the Retail Class shares of the Funds.
 
  Loomis Sayles may pay certain broker-dealers and financial intermediaries
whose customers own shares of the Funds a continuing fee in an amount of up to
 .25% annually of the value of Fund shares held for those customers' accounts.
These fees are paid by Loomis Sayles out of its own assets and are not
assessed against the Funds.
 
                                      27
<PAGE>
 
                            PORTFOLIO TRANSACTIONS
 
  Portfolio turnover considerations will not limit Loomis Sayles' investment
discretion in managing the Funds' assets. The Funds anticipate that their
portfolio turnover rates will vary significantly from time to time depending
on the volatility of economic and market conditions. High portfolio turnover
may involve higher costs and higher levels of taxable gains.
 
                            HOW TO PURCHASE SHARES
 
  An investor may make an initial purchase of shares of any Fund by submitting
a completed application form and payment to:
 
      Boston Financial Data Services
      P.O. Box 8314
      Boston, Massachusetts 02266-8314
      Attn: Loomis Sayles Funds
 
  The minimum initial investment for Retail Class of the Funds' shares
("Retail Shares") is $25,000 in that Fund. This minimum initial investment
does not apply to purchases through financial intermediaries including, but
not limited to, certain financial advisers, broker dealers, 401(k) alliances,
wrap programs, no transaction fee programs, bank trust departments, financial
consultants and insurance companies. The minimum investment may be waived in
whole or in part by Loomis Sayles in its sole discretion. Subsequent
investments must be at least $50.
 
  Shares of any Fund may be purchased by (i) cash, (ii) exchanging Retail
Class shares of any Fund (or any other series of Loomis Sayles Funds which
offers Retail Class shares), provided the value of the shares exchanged meets
the investment minimum of the Fund into which the exchange is made,
(iii) exchanging securities on deposit with a custodian acceptable to Loomis
Sayles or (iv) a combination of such securities and cash. Loomis Sayles will
not approve the acceptance of securities in exchange for shares of any Fund
unless (1) Loomis Sayles, in its sole discretion, believes the securities are
appropriate investments for the Fund; (2) the investor represents and agrees
that all securities offered to the Fund can be resold by the Fund without
restriction under the Securities Act of 1933, as amended (the "Securities
Act") or otherwise; and (3) the securities are eligible to be acquired under
the Fund's investment policies and restrictions. No investor owning 5% or more
of a Fund's shares may purchase additional shares of that Fund by exchange of
securities. In all cases Loomis Sayles reserves the right to reject any
securities that are proposed for exchange. Securities accepted by Loomis
Sayles in exchange for Fund shares will be valued in the same manner as the
Fund's assets as described below as of
 
                                      28
<PAGE>
 
the time of the Fund's next determination of net asset value after such
acceptance. All dividends and subscription or other rights which are reflected
in the market price of accepted securities at the time of valuation become the
property of the Fund and must be delivered to the Fund upon receipt by the
investor from the issuer. A gain or loss for federal income tax purposes would
be realized upon the exchange by an investor that is subject to federal income
taxation, depending upon the investor's basis in the securities tendered. An
investor who wishes to purchase shares by exchanging securities should obtain
instructions by calling 800-633-3330, option 5.
 
  All purchases made by check should be in U.S. dollars and made payable to
State Street Bank and Trust Company. Third party checks will not be accepted.
When purchases are made by check or periodic account investment, redemption
will not be allowed until the investment being redeemed has been in the
account for 15 calendar days.
 
  Upon acceptance of an investor's order, Boston Financial Data Services, Inc.
("BFDS"), the shareholder servicing agent for State Street Bank and Trust
Company ("State Street Bank"), opens an account, applies the payment to the
purchase of full and fractional Fund shares and mails a statement of the
account confirming the transaction.
 
  After an account has been established, an investor may send subsequent
investments at any time directly to BFDS at the above address. The remittance
must be accompanied by either the account identification slip detached from a
statement of account or a note containing sufficient information to identify
the account, i.e., the Fund name and the investor's account number or name and
social security number.
 
  Subsequent investments can also be made by federal funds wire. Investors
should instruct their banks to wire federal funds to State Street Bank and
Trust Company, ABA #011000028. The text of the wire should read as follows:
"$    amount, STATE STREET BOS ATTN Mutual Funds. Credit Fund (Fund Name and
Retail Class), DDA #9904-622-9, Account Name, Account Number." A bank may
charge a fee for transmitting funds by wire.
 
  Each Fund and the Distributor reserve the right to reject any purchase
order, including orders in connection with exchanges, for any reason which the
Fund or the Distributor in its sole discretion deems appropriate. Although the
Funds do not presently anticipate that they will do so, each Fund reserves the
right to suspend or change the terms of the offering of its shares.
 
  The price an investor pays will be the per share net asset value next
calculated after a proper investment order is received by the Trust's transfer
or other agent or subagent. Shares of each Fund are sold with no sales charge.
The
 
                                      29
<PAGE>
 
net asset value of each Fund's shares is calculated once daily as of the close
of regular trading on the New York Stock Exchange on each day the Exchange is
open for trading, by dividing the Fund's net assets by the number of shares
outstanding. Portfolio securities are valued at their market value as more
fully described in the Statement of Additional Information.
 
  The Distributor may accept telephone orders from broker-dealers who have
been previously approved by the Distributor. It is the responsibility of such
broker-dealers to promptly forward purchase or redemption orders to the
Distributor. Although there is no sales charge imposed by the Fund or the
Distributor, broker-dealers may charge the investor a transaction-based fee or
other fee for their services at either the time of purchase or the time of
redemption. Such charges may vary among broker-dealers but in all cases will
be retained by the broker-dealer and not remitted to the Fund.
 
  Each Fund also offers an Institutional Class of shares that, except for the
Loomis Sayles Bond Fund, has a $1 million minimum investment for certain
investors and bears lower expenses. The minimum investment for the
Institutional Class of shares of the Loomis Sayles Bond Fund is $25,000.
Because of its lower expenses, the Institutional Class of shares of each Fund
is expected to have a higher total return than the Retail Class of shares.
 
  The Loomis Sayles Bond Fund also offers an Admin Class of shares that is
offered exclusively through intermediaries, who will be the record owners of
the shares. Because of its lower expenses, the Retail Class of shares of the
Loomis Sayles Bond Fund is expected to have a higher total return than the
Admin Class of shares.
 
                             SHAREHOLDER SERVICES
 
  The Funds offer the following shareholder services, which are more fully
described in the Statement of Additional Information. Explanations and forms
are available from BFDS. Telephone redemption and exchange privileges will be
established automatically when an investor opens an account unless an investor
elects on the application to decline the privileges. Other privileges must be
specifically elected. A signature guarantee will be required to establish a
privilege after an account is opened.
   
  FREE EXCHANGE PRIVILEGE. Retail Class shares of any Fund may be exchanged
for Retail Class shares of any other Fund (or any other fund that is a series
of Loomis Sayles Funds and that offers Retail Class shares) or for shares of
certain money market funds advised by New England Funds Management, L.P., an
affiliate of Loomis Sayles, provided the value of the shares exchanged meets
the investment minimum of that Fund and, in the case of the Loomis     
 
                                      30
<PAGE>
 
   
Sayles High Yield Fund, Loomis Sayles has approved the exchange of shares.
Exchanges may be made by written instructions or by telephone, unless an
investor elected on the application to decline telephone exchange privileges.
The exchange privilege should not be viewed as a means for taking advantage of
short-term swings in the market, and the Funds reserve the right to terminate
or limit the privilege of any shareholder who makes more than four exchanges
in any calendar year. The Funds may terminate or change the terms of the
exchange privilege at any time, upon 60 days' notice to shareholders. An
exchange is a taxable event for federal income tax purposes in which a gain or
loss would be realized by an investor that is subject to federal income
taxation.     
 
  RETIREMENT PLANS. The Funds' shares may be purchased by all types of tax-
deferred retirement plans. Loomis Sayles makes available retirement plan forms
for IRAs.
 
  SYSTEMATIC WITHDRAWAL PLAN. If the value of an account is at least $25,000,
an investor may have periodic cash withdrawals automatically paid to the
investor or any person designated by the investor.
 
  AUTOMATIC INVESTMENT PLAN. Voluntary monthly investments of at least $50 may
be made automatically by pre-authorized withdrawals from an investor's
checking account.
 
                             HOW TO REDEEM SHARES
 
  An investor can redeem shares by sending a written request to Boston
Financial Data Services, Inc., P.O. Box 8314, Boston, Massachusetts 02266.
Proceeds from a written request may be sent to the investor in the form of a
check. As described below, an investor may also redeem shares by calling BFDS
at 800-626-9390. Proceeds resulting from a telephone redemption request can be
wired to an investor's bank account or sent by check in the name of the
registered owners to their record address.
 
  The written request must include the name of the Fund, the account number,
the exact name(s) in which the shares are registered, and the number of shares
or the dollar amount to be redeemed. All owners of the shares must sign the
request in the exact names in which the shares are registered (this appears on
an investor's confirmation statement) and should indicate any special capacity
in which they are signing (such as trustee or custodian or on behalf of a
partnership, corporation or other entity). Shareholders requesting that
redemption proceeds be wired to their bank accounts must provide specific wire
instructions.
 
  If (1) an investor is redeeming shares worth more than $50,000, (2) an
investor is requesting that the proceeds check be made out to someone other
 
                                      31
<PAGE>
 
than the registered owners or be sent to an address other than the record
address, (3) the account registration has changed within the last 30 days or
(4) an investor is instructing us to wire the proceeds to a bank account not
designated on the application, the investor must have his or her signature
guaranteed by an eligible guarantor. This requirement may be waived by Loomis
Sayles in its sole discretion. Eligible guarantors include commercial banks,
trust companies, savings associations, credit unions and brokerage firms that
are members of domestic securities exchanges. Before submitting the redemption
request, an investor should verify with the guarantor institution that it is
an eligible guarantor. Signature guarantees by notaries public are not
acceptable.
 
  When an investor telephones a redemption request, the proceeds are wired to
the bank account previously chosen by the investor. A wire fee (currently $5)
will be deducted from the proceeds. A telephonic redemption request must be
received by BFDS prior to the close of regular trading on the New York Stock
Exchange. If an investor telephones a request to BFDS after the Exchange
closes or on a day when the Exchange is not open for business, BFDS cannot
accept the request and a new one will be necessary. If an investor decides to
change the bank account to which proceeds are to be wired, the investor must
send in this change in writing with a signature guarantee. Telephonic
redemptions may only be made if the investor's bank is a member of the Federal
Reserve System or has a correspondent bank that is a member of the System.
Unless an investor indicates otherwise on the account application, BFDS will
be authorized to act upon redemption and exchange instructions received by
telephone from the investor or any person claiming to act as the investor's
representative who can provide BFDS with the investor's account registration
and address as it appears on the records of State Street Bank. BFDS will
employ these or other reasonable procedures to confirm that instructions
communicated by telephone are genuine; the Fund, State Street Bank, BFDS, the
Distributor and Loomis Sayles will not be liable for any losses due to
unauthorized or fraudulent instructions if these or other reasonable
procedures are followed. For information, consult BFDS. In times of heavy
market activity, an investor who encounters difficulty in placing a redemption
or exchange order by telephone may wish to place the order by mail as
described above.
   
  The redemption price will be the net asset value per share next determined
after the redemption request and any necessary special documentation are
received by BFDS in proper form.     
 
  Proceeds resulting from a written redemption request will normally be mailed
to an investor within seven days after receipt of the investor's request in
good order. Telephonic redemption proceeds will normally be wired to an
investor's bank on the first business day following receipt of a proper
redemption request. If an investor purchased shares by check and the check was
 
                                      32
<PAGE>
 
deposited less than 15 days prior to the redemption request, the Fund may
withhold redemption proceeds until the check has cleared.
 
  The Fund may suspend the right of redemption and may postpone payment for
more than seven days when the New York Stock Exchange is closed for other than
weekends or holidays, or if permitted by the rules of the SEC when trading on
the Exchange is restricted or during an emergency which makes it impracticable
for the Fund to dispose of its securities or to determine fairly the value of
its net assets, or during any other period permitted by the SEC for the
protection of investors.
 
                    CALCULATION OF PERFORMANCE INFORMATION
 
  The Funds' investment performance may from time to time be included in
advertisements about the Funds. "Yield" for each class of shares is calculated
by dividing the annualized net investment income per share during a recent 30-
day period by the maximum public offering price per share of the class on the
last day of that period.
 
  For purposes of calculating yield, net investment income is calculated in
accordance with SEC regulations and may differ from net investment income as
determined for financial reporting purposes. SEC regulations require that net
investment income be calculated on a "yield-to-maturity" basis, which has the
effect of amortizing any premiums or discounts in the current market value of
fixed income securities. The current dividend rate is based on net investment
income as determined for tax purposes, which may not reflect amortization in
the same manner.
       
  "Total return" for the one-, five- and ten-year periods (or for the life of
a class, if shorter) through the most recent calendar quarter represents the
average annual compounded rate of return on an investment of $1,000 in a Fund.
Total return may also be presented for other periods.
 
                DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES
   
  The Bond, Intermediate Maturity Bond and Investment Grade Bond Funds declare
and pay dividends quarterly; the Global Bond Fund declares and pays its net
investment income to shareholders as dividends annually; the Short-Term Bond
Fund declares dividends daily and makes payments monthly. Each Fund also
distributes all of its net capital gains realized from the sale of portfolio
securities. Any capital gain distributions are normally made annually, but
may, to the extent permitted by law, be made more frequently as deemed
advisable by the trustees of the Trust. The Trust's trustees may change the
frequency with which the Funds declare or pay dividends.     
 
                                      33
<PAGE>
 
   
  Dividends and capital gain distributions will automatically be reinvested in
additional shares of the same Fund unless an investor has elected to receive
cash. Each Fund intends to qualify as a regulated investment company under the
Internal Revenue Code of 1986, as amended. As such, so long as a Fund
distributes substantially all its net investment income and net capital gains
to its shareholders, the Fund itself does not pay any federal income tax to
the extent such income and gains are so distributed. An investor's income
dividends and short term capital gain distributions are taxable as ordinary
income whether distributed in cash or additional shares. Distributions
designated by a Fund as deriving from net gains on securities held for more
than one year will be taxable as such (generally at a 20% rate for
noncorporate shareholders) whether distributed in cash or additional shares
and regardless of how long an investor has owned shares of the Fund.     
   
  A dividend or distribution made shortly after the purchase of shares of a
Fund by a shareholder, although in effect a return of capital to that
particular shareholder, would be taxable to him or her as described above. If
a shareholder held shares six months or less and during that period received a
distribution of net capital gains, any loss realized on the sale of such
shares during such six-month period would be a long-term capital loss to the
extent of such distribution.     
 
  Each Fund is required to withhold 31% of any redemption proceeds (including
the value of shares exchanged) and all income dividends and capital gain
distributions it pays (1) if an investor does not provide a correct, certified
taxpayer identification number, (2) if the Fund is notified that an investor
has underreported income in the past, or (3) if an investor fails to certify
to the Fund that he or she is not subject to such withholding.
 
  Dividends derived from interest on U.S. Government Securities may be exempt
from state and local taxes.
 
  State Street Bank will send investors and the IRS an annual statement
detailing federal tax information, including information about dividends and
distributions paid during the preceding year. An investor should keep this
statement as a permanent record. A fee may be charged for any duplicate
information requested.
 
NOTE:   The foregoing summarizes certain tax consequences of investing in the
        Funds. Before investing, an investor should consult his or her own tax
        adviser for more information concerning federal, foreign, state and
        local tax consequences of investing in, redeeming or exchanging Fund
        shares.
 
                                      34
<PAGE>
 
                                                                     APPENDIX A
 
                    DESCRIPTION OF BOND RATINGS ASSIGNED BY
                             STANDARD & POOR'S AND
                        MOODY'S INVESTORS SERVICE, INC.
 
STANDARD & POOR'S
 
                                      AAA
 
  This is the highest rating assigned by Standard & Poor's to a debt
obligation and indicates an extremely strong capacity to pay interest and
repay principal.
 
                                      AA
 
  Bonds rated AA also qualify as high quality debt obligations. Capacity to
pay interest and repay principal is very strong, and in the majority of
instances they differ from AAA issues only in small degree.
 
                                       A
 
  Bonds rated A have a strong capacity to pay interest and repay principal,
although they are somewhat more susceptible to the adverse effects of changes
in circumstances and economic conditions than obligations in higher rated
categories.
 
                                      BBB
 
  Bonds rated BBB are regarded as having an adequate capacity to pay interest
and repay principal. Whereas they normally exhibit adequate protection
parameters, adverse economic conditions or changing circumstances are more
likely to lead to a weakened capacity to repay principal and pay interest for
bonds in this category than for bonds in higher rated categories.
 
                                BB, B, CCC, CC
 
  Bonds rated BB, B, CCC and CC are regarded, on balance, as predominantly
speculative with respect to capacity to pay interest and repay principal in
accordance with the terms of the obligation. BB indicates the lowest degree of
speculation and CC the highest degree of speculation. While such bonds will
likely have some quality and protective characteristics, these are outweighed
by large uncertainties or major risk exposures to adverse conditions.
 
                                      35
<PAGE>
 
                                       C
 
  The rating C is reserved for income bonds on which no interest is being
paid.
 
                                       D
 
  Bonds rated D are in default, and payment of interest and/or repayment of
principal is in arrears.
 
                                       R
 
  This symbol is attached to the ratings of instruments with significant
noncredit risks such as risks to principal or volatility of expected returns.
 
  Plus (+) or Minus (-): The ratings from AA to B may be modified by the
addition of a plus or minus sign to show relative standing within the major
rating categories.
 
MOODY'S INVESTORS SERVICE, INC.
 
                                      AAA
 
  Bonds that are rated Aaa are judged to be of the best quality. They carry
the smallest degree of investment risk and are generally referred to as "gilt
edged." Interest payments are protected by a large, or by an exceptionally
stable, margin, and principal is secure. While the various protective elements
are likely to change, such changes as can be visualized are most unlikely to
impair the fundamentally strong position of such issues.
 
                                      AA
 
  Bonds that are rated Aa are judged to be high quality by all standards.
Together with the Aaa group they comprise what are generally known as high
grade bonds. They are rated lower than the best bonds because margins of
protection may not be as large as in Aaa securities or fluctuation of
protective elements may be of greater amplitude or there may be other elements
present that make the long-term risks appear somewhat larger than in Aaa
securities.
 
                                       A
 
  Bonds that are rated A possess many favorable investment attributes and are
to be considered as upper medium grade obligations. Factors giving security to
principal and interest are considered adequate, but elements may be present
that suggest a susceptibility to impairment sometime in the future.
 
                                      36
<PAGE>
 
                                      BAA
 
  Bonds that are rated Baa are considered as medium grade obligations; i.e.,
they are neither highly protected nor poorly secured. Interest payments and
principal security appear adequate for the present, but certain protective
elements may be lacking or may be characteristically unreliable over any great
length of time. Such bonds lack outstanding investment characteristics and, in
fact, have speculative characteristics as well.
 
                                      BA
 
  Bonds which are rated Ba are judged to have speculative elements; their
future cannot be considered as well assured. Often, the protection of interest
and principal payments may be very moderate, and thereby not well safeguarded
during both good and bad times over the future. Uncertainty of position
characterizes bonds in this class.
 
                                       B
 
  Bonds which are rated B generally lack characteristics of the desirable
investment. Assurance of interest and principal payments or of maintenance of
other terms of the contract over any long period of time may be small.
 
                                      CAA
 
  Bonds which are rated Caa are of poor standing. Such issues may be in
default or there may be present elements of danger with respect to principal
or interest.
 
                                      CA
 
  Bonds which are rated Ca represent obligations which are speculative in a
high degree. Such issues are often in default or have other marked
shortcomings.
 
                                       C
 
  Bonds which are rated C are the lowest rated class of bonds, and issues so
rated can be regarded as having extremely poor prospects of ever attaining any
real investment standing.
 
                                      37
<PAGE>
 
  Should no rating be assigned by Moody's, the reason may be one of the
following:
 
  1. An application for rating was not received or accepted.
 
  2. The issue or issuer belongs to a group of securities that are not rated
     as a matter of policy.
 
  3. There is a lack of essential data pertaining to the issue or issuer.
 
  4. The issue was privately placed in which case the rating is not
     published in Moody's publications.
 
  Suspension or withdrawal may occur if new and material circumstances arise,
the effects of which preclude satisfactory analysis; if there is no longer
available reasonable up-to-date data to permit a judgment to be formed; if a
bond is called for redemption; or for other reasons.
 
Note: Those bonds in the Aa, A, Baa, Ba and B groups which Moody's believes
      possess the strongest investment attributes are designated by the
      symbols Aa1, A1, Baa1, Ba1 and B1.
 
                                      38
<PAGE>
 
INVESTMENT ADVISER Loomis, Sayles &
Company, L.P. One Financial Center Boston,
Massachusetts 02111
 
DISTRIBUTOR Loomis Sayles Distributors,
L.P. One Financial Center Boston,
Massachusetts 02111
 
TRANSFER AND DIVIDEND PAYING AGENT AND
CUSTODIAN OF ASSETS State Street Bank and
Trust Company Boston, Massachusetts 02102
 
SHAREHOLDER SERVICING AGENT FOR STATE
STREET BANK AND TRUST COMPANY Boston
Financial Data Services, Inc. P.O. Box 8314
Boston, Massachusetts 02266
 
LEGAL COUNSEL Ropes & Gray One
International Place Boston, Massachusetts
02110
   
INDEPENDENT ACCOUNTANTS
PricewaterhouseCoopers LLP One Post Office
Square Boston, Massachusetts 02109     
<PAGE>

[LOGO OF LOOMIS SAYLES FUNDS APPEARS HERE] 
 
 ONE FINANCIAL CENTER . BOSTON, MASSACHUSETTS 02111 . (800) 633-3330
 
THE LOOMIS SAYLES FUNDS
 
 ADMIN CLASS SHARES OF:
 
  LOOMIS SAYLES BOND FUND
 
  LOOMIS SAYLES SMALL CAP VALUE FUND
<PAGE>
 
PROSPECTUS                                                    
                                                           JANUARY 1, 1999     
 
THE LOOMIS SAYLES FUNDS--ADMIN CLASS
  Loomis Sayles Bond Fund and Loomis Sayles Small Cap Value Fund (the "Funds"
and each a "Fund"), each a series of Loomis Sayles Funds (the "Trust"), are
separately managed, no-load mutual funds and each Fund has its own investment
objective and policies. Loomis, Sayles & Company, L.P. ("Loomis Sayles") is
the investment adviser of each Fund.
   
  The Funds offer three classes of shares: an Admin Class that is described in
this Prospectus and an Institutional Class and a Retail Class that are
described in separate prospectuses. This Prospectus concisely describes the
information that an investor should know before investing in the Admin Class
shares of the Fund. Please read it carefully and keep it for future reference.
A Statement of Additional Information (SAI) dated January 1, 1999, as revised
from time to time, is available free of charge; write to Loomis Sayles
Distributors, L.P. (the "Distributor"), One Financial Center, Boston,
Massachusetts 02111 or telephone 800-633-3330. The SAI, which contains more
detailed information about the Funds, has been filed with the Securities and
Exchange Commission (the "SEC") and is available along with other related
materials on the SEC's Internet Web site (http://www.sec.gov). The SAI is
incorporated by reference (legally forms a part of the Prospectus). To obtain
more information about the Institutional Class or Retail Class, please call
the Distributor toll-free at 800-633-3330, contact your financial
intermediary, or visit our Internet Website (http://www.loomissayles.com).
    
  For information about:                    For all other information about
   .Establishing an account                 the Funds:
   .Account procedures and status           CALL 800-633-3330
   .Exchanges
   .Shareholder services
  CALL 800-626-9390
 
  THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HEREIN HAS THE
SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED
UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE
CONTRARY IS A CRIMINAL OFFENSE.
 
 
 
                                       1
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>   
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
SUMMARY OF EXPENSES.......................................................   3
FINANCIAL HIGHLIGHTS......................................................   4
THE TRUST.................................................................   6
INVESTMENT OBJECTIVE AND POLICIES.........................................   6
MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS AND RISK CONSIDERATIONS.....   8
THE FUNDS' INVESTMENT ADVISER.............................................  18
FUND EXPENSES.............................................................  19
PORTFOLIO TRANSACTIONS....................................................  19
HOW TO PURCHASE SHARES....................................................  20
SHAREHOLDER SERVICES......................................................  21
HOW TO REDEEM SHARES......................................................  22
CALCULATION OF PERFORMANCE INFORMATION....................................  23
DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES...........................  24
APPENDIX A
  DESCRIPTION OF BOND RATINGS.............................................  26
</TABLE>    
 
                                       2
<PAGE>
 
                              SUMMARY OF EXPENSES
               (FOR AN ADMIN CLASS SHARE OF THE INDICATED FUND)
   
  The following information is provided as an aid in understanding the various
expenses that an investor in a Fund will bear indirectly. The information
about each Fund shown below is based on expenses for the Funds' first fiscal
year. The information below should not be considered a representation of past
or future expenses, as actual expenses may be greater or less than those
shown. Also, the 5% annual return assumed in the Example should not be
considered a representation of investment performance, as actual performance
will vary.     
 
<TABLE>   
<CAPTION>
                                                                      SMALL CAP
                                                             BOND       VALUE
                                                             FUND       FUND
                                                             ----     ---------
 <S>                                                         <C>      <C>
 Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on Purchases (as % of offering
  price)..................................................   none       none
 Maximum Sales Load Imposed on Reinvested Dividends (as %
  of offering price)......................................   none       none
 Maximum Deferred Sales Load (as % of original purchase
  price or redemption proceeds)...........................   none       none
 Redemption Fees/1...................................../..   none       none
 Exchange Fees............................................   none       none
 Annual Fund Operating Expenses (as a percentage of
  average net assets):
 Management Fees..........................................    .60%       .75%
 12b-1 Fees/3........................................../..    .25%       .25%
 Administrative Fees/4................................./..    .25%       .25%
 Other Operating Expenses (after expense reimbursement
  where indicated)........................................    .15%/2/    .25%/2/
 Total Fund Operating Expenses............................   1.25%/2/   1.50%/2/
 Example:
 An investor would pay the following expenses on a $1,000
  investment assuming a 5% annual return (with or without
  a redemption at the end of each time period):
 One Year.................................................   $ 13       $ 15
 Three Years..............................................   $ 40       $ 47
</TABLE>    
- -----------
/1/A $5 charge applies to any wire transfer of redemption proceeds.
   
/2/Loomis Sayles has voluntarily agreed, for an indefinite period, to limit
  the Total Operating Expenses, exclusive of Administrative Fees, of the Admin
  Class of the Bond Fund and Small Cap Value Fund to 1.00% and 1.25%,
  respectively. Without this agreement Other Operating Expenses (including
  12b-1 and Administrative Fees) and Total Operating Expenses would have been
  5.72% and 6.32% for the Bond Fund and 3.24% and 3.99% for the Small Cap 
  Value Fund, respectively.
 
     
/3/Because of the ongoing nature of the 12b-1 fees, long-term shareholders may
  pay more than the economic equivalent of the maximum front-end sales charge
  permitted by the rules of the National Association of Securities Dealers,
  Inc.
/4/Administrative fees shown represent the maximum amount presently authorized
  by the Trustees.
 
                                       3
<PAGE>
 
                             FINANCIAL HIGHLIGHTS
                     
                  (FOR AN ADMIN CLASS SHARE OF THE FUNDS     
                  
               OUTSTANDING THROUGHOUT THE INDICATED PERIOD)     
   
  The financial highlights tables that follow have been audited by
PricewaterhouseCoopers LLP, independent accountants. The following information
should be read in conjunction with the financial highlights, financial
statements and the notes thereto contained in the Funds' 1998 Annual Report,
which is incorporated by reference in this Prospectus and the Statement of
Additional Information.     
 
<TABLE>   
<CAPTION>
                                                              BOND FUND
                                                            --------------
                                                              JANUARY 2*
                                                                  TO
                                                            SEPTEMBER 30**
                                                                 1998
                                                            --------------
 <S>                                                        <C>            
 Net asset value, beginning of period.....................      $12.83
                                                                ------
 Income from investment operations--
 Net investment income (loss).............................        0.47
 Net realized and unrealized gain (loss) on investments...       (0.62)
                                                                ------
  Total from investment operations........................       (0.15)
                                                                ------
 Less distributions--
 Dividends from net investment income.....................       (0.40)
                                                                ------
  Total distributions.....................................       (0.40)
                                                                ------
 Net asset value, end of period...........................      $12.28
                                                                ======
 Total return (%)***......................................        (1.3)++
 Net assets, end of period (000)..........................      $  630
 Ratio of operating expenses to average net assets
  (%)****.................................................        1.25+
 Ratio of net investment income to average net assets
  (%).....................................................        7.45+
 Portfolio turnover rate (%)..............................          24++
 Without giving effect to voluntary expense limitations:
 The ratio of operating expenses to average net assets
  would have been (%).....................................        6.32+
 Net investment income per share would have been..........      $ 0.15
</TABLE>    
- -----------
       
   
   * Commencement of investment operations.     
   
  ** The Fund's fiscal year-end changed to September 30 from December 31.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
     
  ++ Periods less than one year are not annualized.     

                                       4
<PAGE>
 
<TABLE>   
<CAPTION>
                                                              SMALL CAP
                                                              VALUE FUND
                                                            --------------
                                                              JANUARY 2*
                                                                  TO
                                                            SEPTEMBER 30**
                                                                 1998
                                                            --------------
 <S>                                                        <C>           
 Net asset value, beginning of period.....................      $18.62
                                                                ------
 Income from investment operations--
 Net investment income (loss).............................        0.03
 Net realized and unrealized gain (loss) on investments...       (3.11)
                                                                ------
  Total from investment operations........................       (3.08)
                                                                ------
 Net asset value, end of period...........................      $15.54
                                                                ======
 Total return (%)***......................................       (16.5)++
 Net assets, end of period (000)..........................      $1,046
 Ratio of operating expenses to average net assets
  (%)****.................................................        1.50+
 Ratio of net investment income to average net assets
  (%).....................................................        0.95+
 Portfolio turnover rate (%)..............................          78++
 Without giving effect to voluntary expense limitations:
 The ratios of operating expenses to average net assets
  would have been (%).....................................        3.99+
 Net investment income per share would have been..........      $(0.05)
</TABLE>    
- -----------
          
   * Commencement of investment operations.     
   
  ** The Fund's fiscal year-end changed to September 30 from December 31.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
     
  ++ Periods less than one year are not annualized.     
          
NOTE: Further information about each Fund's performance is contained in the
Funds' 1998 annual reports to shareholders, which may be obtained without
charge.     
 
                                       5
<PAGE>
 
                                   THE TRUST
 
  Each Fund is a series of the Trust. The Trust is a diversified open-end
management investment company organized as a Massachusetts business trust on
February 20, 1991. The Trust is authorized to issue an unlimited number of
full and fractional shares of beneficial interest in multiple series. Shares
are freely transferable and entitle shareholders to receive dividends as
determined by the Trust's board of trustees and to cast a vote for each share
held at shareholder meetings. The Trust does not generally hold shareholder
meetings and will do so only when required by law. Shareholders may call
meetings to consider removal of the Trust's trustees.
 
                       INVESTMENT OBJECTIVE AND POLICIES
 
LOOMIS SAYLES BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
   
  The Fund seeks to achieve its objective by normally investing substantially
all of its assets in fixed income securities, although up to 20% of its total
assets may be invested in preferred stocks. At least 65% of the Fund's total
assets will normally be invested in bonds. The fixed income securities in
which the Fund may invest include corporate securities, securities issued or
guaranteed by the U.S. Government or its authorities or instrumentalities
("U.S. Government Securities"), commercial paper, zero coupon securities,
mortgage-backed securities, stripped mortgage-backed securities,
collateralized mortgage obligations ("CMOs"), asset-backed securities, when-
issued securities, real estate investment trusts ("REITs"), Rule 144A
securities, repurchase agreements and convertible securities. The Fund may
engage in options and futures transactions, repurchase transactions, foreign
currency hedging transactions and swap transactions.     
   
  The Fund may invest any portion of its assets in securities of Canadian
issuers, and up to 20% of its total assets in securities of other foreign
issuers. The Fund may also invest up to 35% of its total assets in securities
of below investment grade quality (commonly known as "junk bonds"). Securities
of below investment grade quality are securities rated below the top four
rating categories by each major rating agency that has rated the security,
including securities in the lowest rating categories, and unrated securities
that Loomis Sayles determines to be of comparable quality.     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
    
                                       6
<PAGE>
 
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:
 
<TABLE>   
<CAPTION>
               STANDARD & POOR'S MOODY'S
               ----------------- -------
      <S>      <C>               <C>
      AAA/Aaa
      AA/Aa
      A/A
      BBB/Baa
      BB/Ba
      B/B
      CCC/Caa
      C/Ca
      D
</TABLE>    
 
LOOMIS SAYLES SMALL CAP VALUE FUND
 
  The Fund's investment objective is long-term capital growth from investments
in common stocks or their equivalent.
   
  The Fund seeks to achieve its objective by investing primarily in equity
securities of small capitalization companies with good earnings growth
potential that Loomis Sayles believes are undervalued by the market. The Fund
will normally invest at least 65% of its total assets in equity securities of
companies with market capitalizations that fall within the capitalization
range of the Russell 2000 Index and may invest up to 35% of its total assets
in larger companies. Loomis Sayles seeks to build a core small capitalization
portfolio of stocks of solid companies with reasonable growth prospects and
that are attractively priced in relation to the companies' earnings with a
smaller emphasis on special situations and turnarounds (companies that have
experienced significant business problems but which Loomis Sayles believes
have favorable prospects for recovery), as well as unrecognized stocks.
Current income is not a consideration in selecting the Fund's investments. The
Fund may invest up to 20% of its total assets in securities of foreign
issuers. The Fund may also engage in foreign currency hedging transactions,
REITs and Rule 144A securities.     
 
BOTH FUNDS
 
  For temporary defensive purposes, each Fund may invest any portion of its
assets in fixed income securities, cash or any other securities deemed
appropriate by Loomis Sayles.
 
  Except for each Fund's investment objective, and any investment policies
that are identified as "fundamental," all of the investment policies of each
Fund may be changed without a vote of Fund shareholders.
 
 
                                       7
<PAGE>
 
                 MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS
                            AND RISK CONSIDERATIONS
 
COMMON STOCKS AND OTHER EQUITY SECURITIES
 
  Each Fund may invest in common stocks and similar equity securities, such as
warrants and convertibles. These securities are volatile and more risky than
some other forms of investment. The value of an investment in a Fund that
invests in equity securities may sometimes decrease. Equity securities of
companies with relatively small market capitalization may be more volatile
than the securities of larger, more established companies and than the broad
equity market indexes.
 
WHEN-ISSUED SECURITIES
 
  Each Fund may purchase securities on a "when-issued" basis. This means that
the Fund will enter into a commitment to buy the security before the security
has been issued. The Fund's payment obligation and the interest rate on the
security are determined when the Fund enters into the commitment. The security
is typically delivered to the Fund 15 to 120 days later. No interest accrues
on the security between the time the Fund enters into the commitment and the
time the security is delivered. If the value of the security being purchased
falls between the time a Fund commits to buy it and the payment date, the Fund
may sustain a loss. The risk of this loss is in addition to the Fund's risk of
loss on the securities actually in its portfolio at the time. In addition,
when the Fund buys a security on a when-issued basis, it is subject to the
risk that market rates of interest will increase before the time the security
is delivered, with the result that the yield on the security delivered to the
Fund may be lower than the yield available on other, comparable securities at
the time of delivery. If a Fund has outstanding obligations to buy when-issued
securities, it will maintain liquid assets in a segregated account at its
custodian bank in an amount sufficient to satisfy these obligations.
   
CONVERTIBLE SECURITIES     
   
  The Bond Fund may invest in convertible securities which include corporate
bonds, notes or preferred stocks of U.S. or foreign issuers that can be
converted into (that is, exchange for) common stocks or other equity
securities at a stated price or rate. Convertible securities also include
other securities, such as warrants, that provide an opportunity for equity
participation. Because convertible securities can be converted into equity
securities, their value will normally vary in some proportion with those of
the underlying equity securities. Convertible securities usually provide a
higher yield than the underlying equity security, however, so that when the
price of the underlying equity security falls, the decline in the price of the
convertible security may sometimes be less     
 
                                       8
<PAGE>
 
   
substantial than that of the underlying equity security. Due to the conversion
feature, convertible securities generally yield less than nonconvertible fixed
income securities of similar credit quality and maturity. The Fund's
investment in convertible securities may at times include securities that have
a mandatory conversion feature, pursuant to which the securities convert
automatically into common stock at a specified date and conversion ratio, or
that are convertible at the option of the issuer. Because conversion is not at
the option of the holder, the Fund may be required to convert the security
into the underlying common stock even at times when the value of the
underlying common stock has declined substantially.     
   
REAL ESTATE INVESTMENT TRUSTS     
   
  Each Fund may invest in REITs. REITs involve certain unique risks in
addition to those risks associated with investing in the real estate industry
in general (such as possible declines in the value of real estate, lack of
availability of mortgage funds or extended vacancies of property). Equity
REITs may be affected by changes in the value of the underlying property owned
by the REITs, while mortgage REITs may be affected by the quality of any
credit extended. REITs are dependent upon management skills, are not
diversified, are subject to heavy cash flow dependency, risks of default by
borrowers and self-liquidation. REITs are also subject to the possibilities of
failing to qualify for tax-free pass-through of income under the Code, and
failing to maintain their exemptions from registration under the Investment
Company Act of 1940 (the "1940 Act").     
   
  Investment in REITs involves risk similar to those associated with investing
in small capitalization companies. REITs may have limited financial resources,
may trade less frequently and in a limited volume and may be subject to more
abrupt or erratic price movements than larger securities.     
   
RULE 144A SECURITIES     
   
  Each Fund may invest in Rule 144A securities, which are privately offered
securities that can be resold only to certain qualified institutional buyers.
Rule 144A securities are treated as illiquid, unless Loomis Sayles has
determined, under guidelines established by the Trust's trustees, that the
particular issue of Rule 144A securities is liquid.     
 
FOREIGN SECURITIES
   
  Each Fund may invest in securities of issuers organized or headquartered
outside the United States ("foreign securities"). The Small Cap Value Fund
will not purchase a foreign security if, as a result, the Fund's holdings of
foreign securities would exceed 20% of the Fund's total assets. The Bond Fund
may invest any portion of its assets in securities of Canadian issuers, but
will not     
 
                                       9
<PAGE>
 
purchase foreign securities other than those of Canadian issuers if, as a
result, such Fund's holdings of non-U.S. and non-Canadian securities would
exceed 20% of the Fund's total assets.
 
  Although investing in foreign securities may increase a Fund's
diversification and reduce portfolio volatility, foreign securities may
present risks not associated with investments in comparable securities of U.S.
issuers. There may be less information publicly available about a foreign
corporate or government issuer than about a U.S. issuer, and foreign corporate
issuers are not generally subject to accounting, auditing and financial
reporting standards and practices comparable to those in the United States.
The securities of some foreign issuers are less liquid and at times more
volatile than securities of comparable U.S. issuers. Foreign brokerage
commissions and securities custody costs are often higher than in the United
States. With respect to certain foreign countries, there is a possibility of
governmental expropriation of assets, confiscatory taxation, political or
financial instability and diplomatic developments that could affect the value
of investments in those countries. A Fund's receipt of interest on foreign
government securities may depend on the availability of tax or other revenues
to satisfy the issuer's obligations.
 
  A Fund's investments in foreign securities may include investments in
countries whose economies or securities markets are not yet highly developed.
Special considerations associated with these investments (in addition to the
considerations regarding foreign investments generally) may include, among
others, greater political uncertainties, an economy's dependence on revenues
from particular commodities or on international aid or development assistance,
currency transfer restrictions, highly limited numbers of potential buyers for
such securities and delays and disruptions in securities settlement
procedures.
 
  Since most foreign securities are denominated in foreign currencies or
traded primarily in securities markets in which settlements are made in
foreign currencies, the value of these investments and the net investment
income available for distribution to shareholders of a Fund investing in these
securities may be affected favorably or unfavorably by changes in currency
exchange rates, exchange control regulations or foreign withholding taxes.
Changes in the value relative to the U.S. dollar of a foreign currency in
which a Fund's holdings are denominated will result in a change in the U.S.
dollar value of the Fund's assets and the Fund's income available for
distribution.
 
  In addition, although part of a Fund's income may be received or realized in
foreign currencies, the Fund will be required to compute and distribute its
income in U.S. dollars. Therefore, if the value of a currency relative to the
U.S. dollar declines after the Fund's income has been earned in that currency,
translated into U.S. dollars and declared as a dividend, but before payment of
the dividend, the Fund could be required to liquidate portfolio securities to
pay
 
                                      10
<PAGE>
 
the dividend. Similarly, if the value of a currency relative to the U.S.
dollar declines between the time the Fund accrues expenses in U.S. dollars and
the time such expenses are paid, the amount of such currency required to be
converted into U.S. dollars will be greater than the equivalent amount in such
currency of such expenses at the time they were incurred.
 
  In determining whether to invest assets of a Fund in securities of a
particular foreign issuer, Loomis Sayles will consider the likely effects of
foreign taxes on the net yield available to the Fund and its shareholders.
Compliance with foreign tax law may reduce a Fund's net income available for
distribution to shareholders.
 
FOREIGN CURRENCY HEDGING TRANSACTIONS
 
  Each Fund may engage in foreign currency exchange transactions to protect
the value of specific portfolio positions or in anticipation of changes in
relative values of currencies in which current or future Fund portfolio
holdings are denominated or quoted. For example, to protect against a change
in the foreign currency exchange rate between the date on which a Fund
contracts to purchase or sell a security and the settlement date for the
purchase or sale, or to "lock in" the equivalent of a dividend or interest
payment in another currency, a Fund might purchase or sell a foreign currency
on a spot (that is, cash) basis at the prevailing spot rate. If conditions
warrant, the Funds may also enter into private contracts to purchase or sell
foreign currencies at a future date ("forward contracts"). The Funds might
also purchase exchange-listed and over-the-counter call and put options on
foreign currencies. Over-the-counter currency options are generally less
liquid than exchange-listed options, and will be treated as illiquid assets.
The Funds may not be able to dispose of over-the-counter options readily.
 
  Foreign currency transactions involve costs and may result in losses.
 
REPURCHASE AGREEMENTS
 
  The Small Cap Value Fund and the Bond Fund may each invest in repurchase
agreements. In repurchase agreements, the Fund buys securities from a seller,
usually a bank or brokerage firm, with the understanding that the seller will
repurchase the securities at a higher price at a later date. Such transactions
afford an opportunity for the Fund to earn a return on available cash at
minimal market risk, although the Fund may be subject to various delays and
risks of loss if the seller is unable to meet its obligations to repurchase.
 
DEBT AND OTHER FIXED INCOME SECURITIES
 
  The Bond Fund may invest in fixed income securities of any maturity. Fixed
income securities pay a specified rate of interest or dividends, or a rate
 
                                      11
<PAGE>
 
that is adjusted periodically by reference to some specified index or market
rate. Fixed income securities include securities issued by federal, state,
local and foreign governments and related agencies, and by a wide range of
private issuers. Because interest rates vary, it is impossible to predict the
income of a Fund that invests in fixed income securities for any particular
period. The net asset value of such a Fund's shares will vary as a result of
changes in the value of the securities in the Fund's portfolio.
 
  Fixed income securities are subject to market and credit risk. Market risk
relates to changes in a security's value as a result of changes in interest
rates generally. In general, the values of fixed income securities increase
when prevailing interest rates fall and decrease when interest rates rise.
Credit risk relates to the ability of the issuer to make payments of principal
and interest.
 
U.S. GOVERNMENT SECURITIES
 
  The Bond Fund may invest in U.S. Government Securities. U.S. Government
Securities have different kinds of government support. For example, some U.S.
Government Securities, such as U.S. Treasury bonds, are supported by the full
faith and credit of the United States, whereas certain other U.S. Government
Securities issued or guaranteed by federal agencies or government-sponsored
enterprises are not supported by the full faith and credit of the United
States.
 
  Although U.S. Government Securities generally do not involve the credit
risks associated with other types of fixed income securities, the market
values of U.S. Government Securities do go up and down as interest rates
change. Thus, for example, the value of an investment in a Fund that holds
U.S. Government Securities may fall during times of rising interest rates.
Yields on U.S. Government Securities tend to be lower than those on corporate
securities of comparable maturities.
 
  Some U.S. Government Securities, such as Government National Mortgage
Association Certificates ("GNMA"), are known as "mortgage-backed" securities.
Interest and principal payments on the mortgages underlying mortgage-backed
U.S. Government Securities are passed through to the holders of the security.
If the Fund purchases mortgage-backed securities at a discount or a premium,
the Fund will recognize a gain or loss when the payments of principal, through
prepayment or otherwise, are passed through to the Fund and, if the payment
occurs in a period of falling interest rates, the Fund may not be able to
reinvest the payment at as favorable an interest rate. As a result of these
principal prepayment features, mortgage-backed securities are generally more
volatile investments than many other fixed income securities.
 
  In addition to investing directly in U.S. Government Securities, the
Fund may purchase certificates of accrual or similar instruments ("strips")
 
                                      12
<PAGE>
 
evidencing undivided ownership interests in interest payments or principal
payments, or both, in U.S. Government Securities. These investment instruments
may be highly volatile.
 
LOWER RATED FIXED INCOME SECURITIES
   
  The Bond Fund may invest up to 35% of its total assets in securities rated
below investment grade (commonly referred to as "junk bonds"). A security will
be treated as being of investment grade quality if at the time the Bond Fund
acquires it at least one major rating agency has rated the security in its top
four rating categories (even if another such agency has issued a lower
rating), or if the security is unrated but Loomis Sayles determines it to be
of investment grade quality. Lower rated fixed income securities generally
provide higher yields, but are subject to greater credit and market risk, than
higher quality fixed income securities. Lower rated fixed income securities
are considered predominantly speculative with respect to the ability of the
issuer to meet principal and interest payments. Achievement of the investment
objective of a Fund investing in lower rated fixed income securities may be
more dependent on Loomis Sayles' own credit analysis than is the case with
higher quality bonds. The market for lower rated fixed income securities may
be more severely affected than some other financial markets by economic
recession or substantial interest rate increases, by changing public
perceptions of this market or by legislation that limits the ability of
certain categories of financial institutions to invest in these securities. In
addition, the secondary market may be less liquid for lower rated fixed income
securities. This lack of liquidity at certain times may affect the values of
these securities and may make the evaluation and sale of these securities more
difficult. Securities in the lowest rating categories may be in poor standing
or in default. Securities in the lowest investment grade category (BBB or Baa)
have some speculative characteristics.     
 
  For more information about the ratings services' descriptions of the various
rating categories, see Appendix A.
 
ZERO COUPON SECURITIES
 
  The Bond Fund may invest in "zero coupon" fixed income securities. These
securities accrue interest at a specified rate, but do not pay interest in
cash on a current basis. The Fund is required to distribute the income on
these securities to Fund shareholders as the income accrues, even though the
Fund is not receiving the income in cash on a current basis. Thus the Fund may
have to sell other investments to obtain cash to make income distributions at
times when Loomis Sayles would not otherwise deem it advisable to do so. The
market value of zero coupon securities is often more volatile than that of
non-zero coupon fixed income securities of comparable quality and maturity.
 
                                      13
<PAGE>
 
MORTGAGE-BACKED SECURITIES
   
  The Bond Fund may invest in mortgage-backed securities, such as GNMA or
Fannie Mae certificates, which differ from traditional debt securities. Among
the major differences are that interest and principal payments are made more
frequently, usually monthly, and that principal may be prepaid at any time
because the underlying mortgage loans generally may be prepaid at any time. As
a result, if the Fund purchases these assets at a premium, a faster-than-
expected prepayment rate will reduce yield to maturity, and a slower-than-
expected prepayment rate will increase yield to maturity. If the Fund
purchases mortgage-backed securities at a discount, faster-than-expected
prepayments will increase, and slower-than-expected prepayments will reduce,
yield to maturity. Prepayments, and resulting amounts available for
reinvestment by the Fund, are likely to be greater during a period of
declining interest rates and, as a result, are likely to be reinvested at
lower interest rates. Accelerated prepayments on securities purchased at a
premium may result in a loss of principal if the premium has not been fully
amortized at the time of prepayment. Although these securities will decrease
in value as a result of increases in interest rates generally, they are likely
to appreciate less than other fixed-income securities when interest rates
decline because of the risk of prepayments.     
 
STRIPPED MORTGAGE-BACKED SECURITIES
 
  The Bond Fund may invest in interest-only and principal-only classes of
mortgage-backed securities ("IOs" and "POs"). The yield to maturity on an IO
or PO is extremely sensitive not only to changes in prevailing interest rates
but also to the rate of principal payments (including prepayments) on the
underlying assets. A rapid rate of principal prepayments may have a measurably
adverse effect on the Fund's yield to maturity to the extent it invests in
IOs. If the assets underlying the IOs experience greater than anticipated
prepayments of principal, the Fund may fail to recoup fully its initial
investment in these securities. Conversely, POs tend to increase in value if
prepayments are greater than anticipated and decline if prepayments are slower
than anticipated.
 
  The secondary market for stripped mortgage-backed securities may be more
volatile and less liquid than that for other mortgage-backed securities,
potentially limiting the Fund's ability to buy or sell those securities at any
particular time.
 
COLLATERALIZED MORTGAGE OBLIGATIONS
 
  The Bond Fund may invest in CMOs. A CMO is a security backed by a portfolio
of mortgages. CMOs may be issued either by U.S. Government instrumentalities
or by non-governmental entities. The issuer's obligation to make interest and
principal payments is secured by the underlying portfolio of mortgages or
mortgage-backed securities. CMOs are issued with a number of
 
                                      14
<PAGE>
 
classes or series which have different maturities and which may represent
interests in some or all of the interest or principal on the underlying
collateral or a combination thereof. CMOs of different classes are generally
retired in sequence as the underlying mortgage loans in the mortgage pool are
repaid. In the event of sufficient early prepayments on such mortgages, the
class or series of CMOs first to mature generally will be retired prior to its
maturity. As with other mortgage-backed securities, the early retirement of a
particular class or series of CMOs held by the Fund could involve the loss of
any premium the Fund paid when it acquired the investment and could result in
the Fund's reinvesting the proceeds at a lower interest rate than the retired
CMO paid. Because of the early retirement feature, CMOs may be more volatile
than many other fixed-income investments.
 
ASSET-BACKED SECURITIES
 
  The Bond Fund may invest in asset-backed securities. Through the use of
trusts and special purpose corporations, automobile and credit card
receivables are securitized in pass-through structures similar to mortgage
pass-through structures or in a pass-through structure similar to the CMO
structure. Generally, the issuers of asset-backed bonds, notes or pass-through
certificates are special purpose entities and do not have any significant
assets other than the receivables securing such obligations. In general, the
collateral supporting asset-backed securities is of shorter maturity than
mortgage loans. Instruments backed by pools of receivables are similar to
mortgage-backed securities in that they are subject to unscheduled prepayments
of principal prior to maturity. When the obligations are prepaid, the Fund
will ordinarily reinvest the prepaid amounts in securities the yields of which
reflect interest rates prevailing at the time. Therefore, the Fund's ability
to maintain a portfolio that includes high-yielding asset-backed securities
will be adversely affected to the extent that prepayments of principal must be
reinvested in securities that have lower yields than the prepaid obligations.
Moreover, prepayments of securities purchased at a premium could result in a
realized loss.
 
SWAP TRANSACTIONS
 
  The Bond Fund may enter into interest rate or currency swaps. The Fund will
enter into these transactions primarily to preserve a return or spread on a
particular investment or portion of its portfolio, to protect against currency
fluctuations, as a duration management technique or to protect against any
increase in the price of securities the Fund anticipates purchasing at a later
date. Interest rate swaps involve the exchange by a Fund with another party of
their respective commitments to pay or receive interest (for example, an
exchange of floating rate payments for fixed rate payments with respect to a
notional amount of principal). A currency swap is an agreement to exchange
cash flows on a notional amount based on changes in the relative values of the
specified
 
                                      15
<PAGE>
 
currencies. The Fund will maintain liquid assets in a segregated custodial
account to cover its current obligations under swap agreements. Because swap
agreements are not exchange-traded, but are private contracts into which the
Fund and a swap counterparty enter as principals, the Fund may experience a
loss or delay in recovering assets if the counterparty were to default on its
obligations.
 
OPTIONS AND FUTURES TRANSACTIONS
 
  The Bond Fund may buy, sell or write options on securities, securities
indexes, currencies or futures contracts and may buy and sell futures
contracts on securities, securities indexes or currencies. The Fund may engage
in these transactions either for the purpose of enhancing investment return,
or to hedge against changes in the value of other assets that the Fund owns or
intends to acquire. Options and futures fall into the broad category of
financial instruments known as "derivatives" and involve special risks. Use of
options or futures for other than hedging purposes may be considered a
speculative activity, involving greater risks than are involved in hedging.
 
  Options can generally be classified as either "call" or "put" options. There
are two parties to a typical options transaction: the "writer" and the
"buyer." A call option gives the buyer the right to buy a security or other
asset (such as an amount of currency or a futures contract) from, and a put
option gives the buyer the right to sell a security or other asset to, the
option writer at a specified price, on or before a specified date. The buyer
of an option pays a premium when purchasing the option, which reduces the
return on the underlying security or other asset if the option is exercised,
and results in a loss if the option expires unexercised. The writer of an
option receives a premium from writing an option, which may increase its
return if the option expires or is closed out at a profit. If the Fund as the
writer of an option is unable to close out an unexpired option, it must
continue to hold the underlying security or other asset until the option
expires, to "cover" its obligation under the option.
 
  A futures contract creates an obligation by the seller to deliver and the
buyer to take delivery of the type of instrument or cash at the time and in
the amount specified in the contract. Although many futures contracts call for
the delivery (or acceptance) of the specified instrument, futures are usually
closed out before the settlement date through the purchase (or sale) of a
comparable contract. If the price of the sale of the futures contract by the
Fund exceeds (or is less than) the price of the offsetting purchase, the Fund
will realize a gain (or loss).
 
  The value of options purchased by the Fund and futures contracts held by the
Fund may fluctuate based on a variety of market and economic factors. In some
cases, the fluctuations may offset (or be offset by) changes in the value of
 
                                      16
<PAGE>
 
securities held in the Fund's portfolio. All transactions in options and
futures involve the possible risk of loss to the Fund of all or a significant
part of the value of its investment. In some cases, the risk of loss may
exceed the amount of the Fund's investment. When the Fund writes a call option
or sells a futures contract without holding the underlying securities,
currencies or futures contracts, its potential loss is unlimited. The Fund
will be required, however, to set aside with its custodian bank liquid assets
in amounts sufficient at all times to satisfy its obligations under options
and futures contracts.
 
  The successful use of options and futures will usually depend on Loomis
Sayles' ability to forecast stock market, currency or other financial market
movements correctly. The Fund's ability to hedge against adverse changes in
the value of securities held in its portfolio through options and futures also
depends on the degree of correlation between changes in the value of futures
or options positions and changes in the values of the portfolio securities.
The successful use of futures and exchange traded options also depends on the
availability of a liquid secondary market to enable the Fund to close its
positions on a timely basis. There can be no assurance that such a market will
exist at any particular time. In the case of options that are not traded on an
exchange ("over-the-counter" options), the Fund is at risk that the other
party to the transaction will default on its obligations, or will not permit
the Fund to terminate the transaction before its scheduled maturity. As a
result of these characteristics, the Fund will treat most over-the-counter
options (and the assets it segregates to cover its obligations thereunder) as
illiquid.
 
  The options and futures markets of foreign countries are small compared to
those of the United States and consequently are characterized in most cases by
less liquidity than are the U.S. markets. In addition, foreign markets may be
subject to less detailed reporting requirements and regulatory controls than
U.S. markets. Furthermore, investments in options in foreign markets are
subject to many of the same risks as other foreign investments. See "Foreign
Securities" above.
 
YEAR 2000
 
  Many computer software systems in use today cannot properly process date-
related information from and after January 1, 2000. Should any of the computer
systems employed by the Funds' major service providers fail to process this
type of information properly, that could have a negative impact on the Funds'
operations and the services that are provided to the Funds' shareholders.
Loomis Sayles and the Distributor have each advised the Funds that they are
reviewing all of their computer systems with the goal of modifying or
replacing such systems prior to January 1, 2000, to the extent necessary to
foreclose any such negative impact. In addition, Loomis Sayles has been
advised by the Funds' custodian that it is also in the process of reviewing
its systems
 
                                      17
<PAGE>
 
with the same goal. As of the date of this prospectus, the Funds and Loomis
Sayles have no reason to believe that these goals will not be achieved.
Similarly, the values of certain of the portfolio securities held by the Funds
may be adversely affected by the inability of the securities' issuers or of
third parties to process this type of information properly.
 
                         THE FUNDS' INVESTMENT ADVISER
 
  The Funds' investment adviser is Loomis Sayles, One Financial Center,
Boston, Massachusetts 02111. Founded in 1926, Loomis Sayles is one of the
country's oldest and largest investment firms. The general partner of Loomis
Sayles is a special purpose corporation that is an indirect wholly-owned
subsidiary of Nvest Company, L.P. ("Nvest Companies"). Nvest Companies'
managing general partner, Nvest Corporation, is a direct wholly-owned
subsidiary of Metropolitan Life Insurance Company ("Met Life"), a mutual life
insurance company. Nvest Companies' advising general partner, Nvest, L.P., is
a publicly traded company listed on the New York Stock Exchange. Nvest
Corporation is the sole general partner of Nvest L.P.
 
  In addition to selecting and reviewing the Fund's investments, Loomis Sayles
provides executive and other personnel for the management of the Funds. The
Trust's board of trustees supervises Loomis Sayles' conduct of the affairs of
the Funds.
       
       
   
  As of October 31, 1998, Charles Schwab & Co. Inc. owned 48% of the Bond Fund
and 16% of the Small Cap Value Fund. As of October 31, 1998, Smith Barney,
Inc. owned 10% of the Small Cap Value Fund. Shareholders holding more than 25%
of a Fund's shares may be deemed to control the relevant Fund.     
 
  Daniel J. Fuss, President of the Trust and Executive Vice President of
Loomis Sayles, has served as the portfolio manager of the Bond Fund since its
commencement of investment operations in 1991. Kathleen C. Gaffney, Vice
President of Loomis Sayles, has served as associate portfolio manager of the
Bond Fund since October, 1997. Mr. Fuss and Ms. Gaffney joined Loomis Sayles
in 1976 and 1984, respectively.
 
  Jeffrey C. Petherick, Vice President of the Trust and of Loomis Sayles, has
served as a portfolio manager of the Small Cap Value Fund since 1993, and Mary
C. Champagne, Vice President of the Trust and of Loomis Sayles, has served as
a portfolio manager of the Small Cap Value Fund since 1995. Mr. Petherick
joined Loomis Sayles in 1990. Before joining Loomis Sayles in 1993, Ms.
Champagne was a portfolio manager at NBD Bank.
 
                                      18
<PAGE>
 
                                 FUND EXPENSES
 
  The Bond Fund pays Loomis Sayles an annual investment advisory fee of .60%
of the Fund's average daily net assets. The Small Cap Value Fund pays Loomis
Sayles an annual investment advisory fee of .75% of the Fund's average daily
net assets. Such investment advisory fees are paid monthly. In addition to the
investment advisory fee, each Fund pays all expenses not expressly assumed by
Loomis Sayles, including taxes, brokerage commissions, fees and expenses of
registering or qualifying the Fund's shares under federal and state securities
laws, fees of the Fund's custodian, transfer agent, independent accountants
and legal counsel, expenses of shareholders' and trustees' meetings, 12b-1
fees, administrative fees, expenses of preparing, printing and mailing
prospectuses to existing shareholders and fees of trustees who are not
directors, officers or employees of Loomis Sayles or its affiliated companies.
 
  Under a Distribution Plan adopted pursuant to Rule 12b-1 under the
Investment Company Act of 1940, each of the Funds pays the Distributor, a
subsidiary of Loomis Sayles, a monthly distribution fee at an annual rate not
to exceed 0.25% of the Fund's average daily net assets attributable to the
Admin Class shares. The Distributor may pay all or any portion of the
distribution fee to securities dealers or other organizations (including, but
not limited to, any affiliate of the Distributor) as commissions, asset-based
sales charges or other compensation with respect to the sale of Admin Class
shares of the Funds, or for providing personal services to investors in Admin
Class shares of the Funds and/or the maintenance of accounts, and may retain
all or any portion of the distribution fee as compensation for the
Distributor's services as principal underwriter of the Admin Class shares of
the Funds.
 
  Each of the Funds may also pay an "administrative fee" at an annual rate of
up to 0.25% of its average daily net assets attributable to the Admin Class to
certain securities dealers or financial intermediaries for providing personal
service and account maintenance for their customers who are shareholders of
the Funds. Loomis Sayles may also pay these parties a continuing fee at an
annual rate of up to 0.25% of the value of Fund shares held for those
customers' accounts, which fees are paid by Loomis Sayles out of its own
assets and are not assessed against the Funds.
 
                            PORTFOLIO TRANSACTIONS
 
  Portfolio turnover considerations will not limit Loomis Sayles' investment
discretion in managing the Funds' assets. The Funds anticipate that their
portfolio turnover rates will vary significantly from time to time depending
on the volatility of economic and market conditions. High portfolio turnover
may involve higher costs and higher levels of taxable gains.
 
                                      19
<PAGE>
 
                            HOW TO PURCHASE SHARES
 
  An intermediary may make an initial purchase of shares of any Fund by
submitting a completed application form and payment to:
 
      Boston Financial Data Services
      P.O. Box 8314
      Boston, Massachusetts 02266-8314
      Attn: Loomis Sayles Funds
 
  Shares of the Fund may be purchased exclusively through intermediaries, who
will be the record owner of the shares. The intermediary may purchase shares
by paying cash or by exchanging Admin Class shares of any Fund.
 
  All purchases made by check should be in U.S. dollars and made payable to
State Street Bank and Trust Company. Third party checks will not be accepted.
When purchases are made by check or periodic account investment, redemption
will not be allowed until the investment being redeemed has been in the
account for 15 calendar days.
 
  Upon acceptance of an order, Boston Financial Data Services ("BFDS") opens
an account, applies the payment to the purchase of full and fractional Fund
shares and mails a statement of the account confirming the transaction.
 
  After an account has been established, the intermediary may send subsequent
investments at any time directly to BFDS at the above address. The remittance
must be accompanied by either the account identification slip detached from a
statement of account or a note containing sufficient information to identify
the account, i.e., the Fund name and the intermediary's account number or name
and tax identification number.
 
  Initial or subsequent investments can also be made by federal funds wire.
For initial investment by wire, contact the Distributor at 800-633-3330,
option 5 for an account number before sending the wire. The intermediary
should instruct its bank to wire federal funds to State Street Bank and Trust
Company, ABA #011000028. The text of the wire should read as follows: "$
amount, STATE STREET BOS ATTN Mutual Funds. Credit Fund (Fund Name and Admin
Class), DDA #9904-622-9, Account Name, Account Number." A bank may charge a
fee for transmitting funds by wire.
 
  Each Fund and the Distributor reserve the right to reject any purchase
order, including orders in connection with exchanges, for any reason which the
Fund or the Distributor in its sole discretion deems appropriate. Although the
Funds do not presently anticipate that they will do so, each Fund reserves the
right to suspend or change the terms of the offering of its shares.
 
                                      20
<PAGE>
 
  The price an intermediary pays will be the per share net asset value next
calculated after a proper investment order is received by the Trust's transfer
or other agent or subagent. Shares of each Fund are sold with no sales charge.
The net asset value of each Fund's shares is calculated once daily as of the
close of regular trading on the New York Stock Exchange on each day the
Exchange is open for trading, by dividing the Fund's net assets by the number
of shares outstanding. Portfolio securities are valued at their market value
as more fully described in the Statement of Additional Information.
 
  The Distributor may accept telephone orders from broker-dealers who have
been previously approved by the Distributor. It is the responsibility of such
broker-dealers to promptly forward purchase or redemption orders to the
Distributor. Although there is no sales charge imposed by the Fund or the
Distributor, broker-dealers may charge the investor a transaction-based fee or
other fee for their services at either the time of purchase or the time of
redemption. Such charges may vary among broker-dealers but in all cases will
be retained by the broker-dealer and not remitted to the Fund.
 
  Each Fund also offers (i) a Retail Class of shares that has a $25,000
minimum investment for certain categories of investors, is offered through
intermediaries and does not bear administrative fees, and (ii) an
Institutional Class of shares that in the case of the Bond Fund has a $25,000
investment mimimum and in the case of the Small Cap Value Fund has a
$1 million minimum investment for certain categories of investors and does not
bear 12b-1 fees or administrative fees. Because of its higher expenses, the
Admin Class of shares of each Fund is expected to have a lower total return
than either of the Institutional Class or Retail Class of shares.
 
                             SHAREHOLDER SERVICES
 
  The Funds offer the following shareholder services, which are more fully
described in the Statement of Additional Information. Explanations and forms
are available from the Distributor. Telephone redemption and exchange
privileges will be established automatically when an intermediary opens an
account unless an intermediary elects on the application to decline the
privileges. Other privileges must be specifically elected. A signature
guarantee will be required to establish a privilege after an account is
opened.
 
  FREE EXCHANGE PRIVILEGE. Admin Class shares of any Fund may be exchanged for
Admin Class shares of any other fund that is a series of Loomis Sayles Funds
and that offers Admin Class shares or for shares of certain money market funds
advised by New England Funds Management, L.P., an affiliate of Loomis Sayles.
Exchanges may be made by written instructions or by telephone, unless an
intermediary elected on the application to decline telephone exchange
 
                                      21
<PAGE>
 
   
privileges. The exchange privilege should not be viewed as a means for taking
advantage of short-term swings in the market, and the Funds reserve the right
to terminate or limit the privilege of any shareholder who makes more than
four exchanges in any calendar year. The Funds may terminate or change the
terms of the exchange privilege at any time, upon 60 days' notice to
shareholders. An exchange is a taxable event for federal income tax purposes
in which a gain or loss would be realized by an investor that is subject to
federal income taxation.     
 
                             HOW TO REDEEM SHARES
   
  An intermediary can redeem shares by sending a written request to the
Distributor. Proceeds from a written request may be sent to the intermediary
in the form of a check. As described below, an intermediary may also redeem
shares by calling the Distributor at 800-626-9390. Proceeds resulting from a
telephone redemption request can be wired to an intermediary's bank account or
sent by check in the name of the intermediary to its record address.     
 
  The written request must include the name of the Fund, the account number,
the exact name(s) in which the shares are registered, and the number of shares
or the dollar amount to be redeemed. Intermediaries requesting that redemption
proceeds be wired to their bank accounts must provide specific wire
instructions.
 
  If (1) an intermediary is requesting that the proceeds check be made out to
someone other than the intermediary or be sent to an address other than the
record address, (2) the account registration has changed within the last 30
days or (3) an intermediary is instructing us to wire the proceeds to a bank
account not designated on the application, the intermediary must have the
signatory's signature guaranteed by an eligible guarantor. Eligible guarantors
include commercial banks, trust companies, savings associations, credit unions
and brokerage firms that are members of domestic securities exchanges. Before
submitting the redemption request, an intermediary should verify with the
guarantor institution that it is an eligible guarantor. Signature guarantees
by notaries public are not acceptable.
 
  When an intermediary telephones a redemption request, the proceeds are wired
to the bank account previously chosen by the intermediary. A wire fee
(currently $5) will be deducted from the proceeds. A telephonic redemption
request must be received by the Distributor prior to the close of regular
trading on the New York Stock Exchange. If an intermediary telephones a
request to the Distributor after the Exchange closes or on a day when the
Exchange is not open for business, the Distributor cannot accept the request
and a new one will be necessary.
 
                                      22
<PAGE>
 
  If an intermediary decides to change the bank account to which proceeds are
to be wired, the intermediary must send in this change in writing with a
signature guarantee. Telephonic redemptions may only be made if the
intermediary's bank is a member of the Federal Reserve System or has a
correspondent bank that is a member of the System. Unless an intermediary
indicates otherwise on the account application, the Distributor will be
authorized to act upon redemption and exchange instructions received by
telephone from the intermediary or any person claiming to act as the
intermediary's representative who can provide the Distributor with the
intermediary's account registration and address as it appears on the records
of State Street Bank. The Distributor will employ these or other reasonable
procedures to confirm that instructions communicated by telephone are genuine;
the Fund, State Street Bank, BFDS, the Distributor and Loomis Sayles will not
be liable for any losses due to unauthorized or fraudulent instructions if
these or other reasonable procedures are followed. For information, consult
the Distributor. In times of heavy market activity, an intermediary who
encounters difficulty in placing a redemption or exchange order by telephone
may wish to place the order by mail as described above.
 
  The redemption price will be the net asset value per share next determined
after the redemption request and any necessary special documentation are
received by the Distributor in proper form.
 
  Proceeds resulting from a written redemption request will normally be mailed
to an intermediary within seven days after receipt of the intermediary's
request in good order. Telephonic redemption proceeds will normally be wired
to an intermediary's bank on the first business day following receipt of a
proper redemption request. If an intermediary purchased shares by check and
the check was deposited less than 15 days prior to the redemption request, the
Fund may withhold redemption proceeds until the check has cleared.
 
  The Fund may suspend the right of redemption and may postpone payment for
more than seven days when the New York Stock Exchange is closed for other than
weekends or holidays, or if permitted by the rules of the SEC when trading on
the Exchange is restricted or during an emergency which makes it impracticable
for the Fund to dispose of its securities or to determine fairly the value of
its net assets, or during any other period permitted by the SEC for the
protection of investors.
 
                    CALCULATION OF PERFORMANCE INFORMATION
 
  The Funds' investment performance may from time to time be included in
advertisements about the Funds or Loomis Sayles Funds. "Yield" for each class
of shares is calculated by dividing the annualized net investment income per
share during a recent 30-day period by the maximum public offering price per
share of the class on the last day of that period.
 
                                      23
<PAGE>
 
  For purposes of calculating yield, net investment income is calculated in
accordance with SEC regulations and may differ from net investment income as
determined for financial reporting purposes. SEC regulations require that net
investment income be calculated on a "yield-to-maturity" basis, which has the
effect of amortizing any premiums or discounts in the current market value of
fixed income securities. The current dividend rate is based on net investment
income as determined for tax purposes, which may not reflect amortization in
the same manner.
 
  "Total return" for the one-, five- and ten-year periods (or for the life of
a class, if shorter) through the most recent calendar quarter represents the
average annual compounded rate of return on an investment of $1,000 in a Fund.
Total return may also be presented for other periods.
 
                DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES
 
  The Bond Fund declares and pays dividends quarterly. The Small Cap Value
Fund declares and pays dividends annually. Each Fund also distributes all of
its net capital gains realized from the sale of portfolio securities. Any
capital gain distributions are normally made annually, but may, to the extent
permitted by law, be made more frequently as deemed advisable by the trustees
of the Trust. The Trust's trustees may change the frequency with which the
Fund declares or pays dividends.
   
  Dividends and capital gain distributions will automatically be reinvested in
additional shares of the same Fund unless an intermediary has elected to
receive cash.     
 
  Each Fund intends to qualify as a regulated investment company under the
Internal Revenue Code of 1986, as amended. As such, so long as a Fund
distributes substantially all its net investment income and net capital gains
to its shareholders, the Fund itself does not pay any federal income tax to
the extent such income and gains are so distributed.
   
  An investor's income dividends and short-term capital gain distributions are
taxable as ordinary income whether distributed in cash or additional shares.
Distributions designated by a Fund as deriving from net gains on securities
held for more than one year will be taxable as such (generally at a 20% rate
for noncorporate shareholders) whether distributed in cash or additional
shares and regardless of how long an investor has owned shares of the Fund.
    
   
  A dividend or distribution made shortly after the purchase of shares of a
Fund by a shareholder, although in effect a return of capital to that
particular shareholder, would be taxable to him or her as described above. If
a shareholder     
 
                                      24
<PAGE>
 
   
held shares six months or less and during that period received a distribution
of net capital gains, any loss realized on the sale of such shares during such
six-month period would be a long-term capital loss to the extent of such
distribution.     
 
  Each Fund is required to withhold 31% of any redemption proceeds (including
the value of shares exchanged) and all income dividends and capital gain
distributions it pays (1) if an intermediary does not provide a correct,
certified taxpayer identification number, (2) if the Fund is notified that an
intermediary has underreported income in the past, or (3) if an intermediary
fails to certify to the Fund that he or she is not subject to such
withholding.
 
  Dividends derived from interest on U.S. Government Securities may be exempt
from state and local taxes.
 
  State Street Bank will send intermediaries and the IRS an annual statement
detailing federal tax information, including information about dividends and
distributions paid during the preceding year. An intermediary should keep this
statement as a permanent record. A fee may be charged for any duplicate
information requested.
 
NOTE:    The foregoing summarizes certain tax consequences of investing in the
         Funds. Before investing, an investor should consult his or her own
         tax adviser for more information concerning the federal, foreign,
         state and local tax consequences of investing in, redeeming or
         exchanging Fund shares.
 
                                      25
<PAGE>
 
                                                                     APPENDIX A
 
                    DESCRIPTION OF BOND RATINGS ASSIGNED BY
                             STANDARD & POOR'S AND
                        MOODY'S INVESTORS SERVICE, INC.
 
STANDARD & POOR'S
 
                                      AAA
 
  This is the highest rating assigned by Standard & Poor's to a debt
obligation and indicates an extremely strong capacity to pay interest and
repay principal.
 
                                      AA
 
  Bonds rated AA also qualify as high quality debt obligations. Capacity to
pay interest and repay principal is very strong, and in the majority of
instances they differ from AAA issues only in small degree.
 
                                       A
 
  Bonds rated A have a strong capacity to pay interest and repay principal,
although they are somewhat more susceptible to the adverse effects of changes
in circumstances and economic conditions than obligations in higher rated
categories.
 
                                      BBB
 
  Bonds rated BBB are regarded as having an adequate capacity to pay interest
and repay principal. Whereas they normally exhibit adequate protection
parameters, adverse economic conditions or changing circumstances are more
likely to lead to a weakened capacity to repay principal and pay interest for
bonds in this category than for bonds in higher rated categories.
 
                                BB, B, CCC, CC
 
  Bonds rated BB, B, CCC and CC are regarded, on balance, as predominantly
speculative with respect to capacity to pay interest and repay principal in
accordance with the terms of the obligation. BB indicates the lowest degree of
speculation and CC the highest degree of speculation. While such bonds will
likely have some quality and protective characteristics, these are outweighed
by large uncertainties or major risk exposures to adverse conditions.
 
                                      26
<PAGE>
 
                                       C
 
  The rating C is reserved for income bonds on which no interest is being
paid.
 
                                       D
 
  Bonds rated D are in default, and payment of interest and/or repayment of
principal is in arrears.
 
                                       R
 
  This symbol is attached to the ratings of instruments with significant
noncredit risks such as risks to principal or volatility of expected returns.
 
  Plus (+) or Minus (-): The ratings from "AA" to "B" may be modified by the
addition of a plus or minus sign to show relative standing within the major
rating categories.
 
MOODY'S INVESTORS SERVICE, INC.
 
                                      AAA
 
  Bonds that are rated Aaa are judged to be of the best quality. They carry
the smallest degree of investment risk and are generally referred to as "gilt
edge." Interest payments are protected by a large, or by an exceptionally
stable, margin, and principal is secure. While the various protective elements
are likely to change, such changes as can be visualized are most unlikely to
impair the fundamentally strong position of such issues.
 
                                      AA
 
  Bonds that are rated Aa are judged to be high quality by all standards.
Together with the Aaa group they comprise what are generally known as high
grade bonds. They are rated lower than the best bonds because margins of
protection may not be as large as in Aaa securities or fluctuation of
protective elements may be of greater amplitude or there may be other elements
present that make the long-term risks appear somewhat larger than in Aaa
securities.
 
                                       A
 
  Bonds that are rated A possess many favorable investment attributes and are
to be considered as upper medium grade obligations. Factors giving security to
principal and interest are considered adequate, but elements may be present
that suggest a susceptibility to impairment sometime in the future.
 
                                      27
<PAGE>
 
                                      BAA
 
  Bonds that are rated Baa are considered as medium grade obligations; i.e.,
they are neither highly protected nor poorly secured. Interest payments and
principal security appear adequate for the present, but certain protective
elements may be lacking or may be characteristically unreliable over any great
length of time. Such bonds lack outstanding investment characteristics and, in
fact, have speculative characteristics as well.
 
                                      BA
 
  Bonds which are rated Ba are judged to have speculative elements; their
future cannot be considered as well assured. Often, the protection of interest
and principal payments may be very moderate, and thereby not well safeguarded
during both good and bad times over the future. Uncertainty of position
characterizes bonds in this class.
 
                                       B
 
  Bonds which are rated B generally lack characteristics of the desirable
investment. Assurance of interest and principal payments or of maintenance of
other terms of the contract over any long period of time may be small.
 
                                      CAA
 
  Bonds which are rated Caa are of poor standing. Such issues may be in
default or there may be present elements of danger with respect to principal
or interest.
 
                                      CA
 
  Bonds which are rated Ca represent obligations which are speculative in a
high degree. Such issues are often in default or have other marked
shortcomings.
 
                                       C
 
  Bonds which are rated C are the lowest rated class of bonds, and issues so
rated can be regarded as having extremely poor prospects of ever attaining any
real investment standing.
 
                                      28
<PAGE>
 
    Should no rating be assigned by Moody's, the reason may be one of the
following:
 
 1. An application for rating was not received or accepted.
 
 2. The issue or issuer belongs to a group of securities that are not rated
    as a matter of policy.
 
 3. There is a lack of essential data pertaining to the issue or issuer.
 
 4. The issue was privately placed in which case the rating is not published
    in Moody's publications.
 
  Suspension or withdrawal may occur if new and material circumstances arise,
the effects of which preclude satisfactory analysis; if there is no longer
available reasonable up-to-date data to permit a judgment to be formed; if a
bond is called for redemption; or for other reasons.
 
Note:  Those bonds in the Aa, A, Baa, Ba and B groups which Moody's believes
       possess the strongest investment attributes are designated by the
       symbols Aa1, A1, Baa1, Ba1 and B1.
 
                                       29
<PAGE>
 
INVESTMENT ADVISER 
Loomis, Sayles & Company, L.P. 
One Financial Center 
Boston, Massachusetts 02111
 
DISTRIBUTOR 
Loomis Sayles Distributors, L.P. 
One Financial Center 
Boston, Massachusetts 02111
 
TRANSFER AND DIVIDEND PAYING AGENT 
AND CUSTODIAN OF ASSETS 
State Street Bank and Trust Company 
Boston, Massachusetts 02102
 
SHAREHOLDER SERVICING AGENT FOR 
STATE STREET BANK AND TRUST COMPANY 
Boston Financial Data Services, Inc. 
P.O. Box 8314 
Boston, Massachusetts 02266
 
LEGAL COUNSEL 
Ropes & Gray 
One International Place 
Boston, Massachusetts 02110

INDEPENDENT ACCOUNTANTS
    
PricewaterhouseCoopers LLP     
One Post Office Square 
Boston, Massachusetts 02109
<PAGE>
 
      ONE FINANCIAL CENTER . BOSTON, MASSACHUSETTS 02111 . (800) 633-3330
 
THE LOOMIS SAYLES FUNDS--EQUITY FUNDS
 
 RETAIL CLASS SHARES OF:
 
          
 
  LOOMIS SAYLES CORE VALUE FUND
 
  LOOMIS SAYLES INTERNATIONAL EQUITY FUND
 
  LOOMIS SAYLES MID-CAP GROWTH FUND
 
  LOOMIS SAYLES MID-CAP VALUE FUND
 
  LOOMIS SAYLES SMALL CAP GROWTH FUND
 
  LOOMIS SAYLES SMALL CAP VALUE FUND
 
  LOOMIS SAYLES STRATEGIC VALUE FUND
 
  LOOMIS SAYLES WORLDWIDE FUND
 
<PAGE>
 
PROSPECTUS                                                    
                                                           JANUARY 1, 1999     
 
THE LOOMIS SAYLES FUNDS--EQUITY FUNDS
   
  Loomis Sayles Core Value Fund, Loomis Sayles International Equity Fund, Loo-
mis Sayles Mid-Cap Growth Fund, Loomis Sayles Mid-Cap Value Fund, Loomis
Sayles Small Cap Growth Fund, Loomis Sayles Small Cap Value Fund, Loomis
Sayles Strategic Value Fund and Loomis Sayles Worldwide Fund (the "Funds" and
each a "Fund"), each a series of Loomis Sayles Funds, are separately managed,
no-load mutual funds, each of which has its own investment objective and poli-
cies. Loomis, Sayles & Company, L.P. ("Loomis Sayles") is the investment ad-
viser of each Fund.     
   
  The Funds offer two classes of shares: a Retail Class that is described in
this Prospectus, and an Institutional Class, which generally has a higher min-
imum investment and bears lower expenses, that is described in a separate pro-
spectus. The Loomis Sayles Small Cap Value Fund also offers a third class of
shares; an Admin Class, bearing higher expenses than the Institutional or Re-
tail Class, that is described in a separate prospectus. This Prospectus con-
cisely describes the information that an investor should know before investing
in the Retail Class shares of any Fund. Please read it carefully and keep it
for future reference. A Statement of Additional Information (SAI) dated Janu-
ary 1, 1999, as revised from time to time, is available free of charge; write
to Loomis Sayles Distributors, L.P. (the "Distributor"), One Financial Center,
Boston, Massachusetts 02111 or telephone 800-633-3330. The SAI, which contains
more detailed information about the Funds, has been filed with the Securities
and Exchange Commission (the "SEC") and is available along with other related
materials on the SEC's Internet Website (http://www.sec.gov). The SAI is in-
corporated herein by reference (legally forms part of the Prospectus). To ob-
tain more information about the Institutional Class or Admin Class of shares,
please call the Distributor toll-free at 800-633-3330, contact your financial
intermediary, or visit our Internet Website (http://www.loomissayles.com).
    
  For information about:                    For all other information about
   .  Establishing an account               the Funds:
   .  Account procedures and status         CALL 800-633-3330
   .  Exchanges
   .  Shareholder services
  CALL 800-626-9390
 
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS
A CRIMINAL OFFENSE.
 
                                       1
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>   
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
SUMMARY OF EXPENSES.......................................................   3
FINANCIAL HIGHLIGHTS......................................................   5
THE TRUST.................................................................  13
INVESTMENT OBJECTIVES AND POLICIES........................................  13
MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS AND RISK CONSIDERATIONS.....  16
THE FUNDS' INVESTMENT ADVISER.............................................  23
FUND EXPENSES.............................................................  25
PORTFOLIO TRANSACTIONS....................................................  26
HOW TO PURCHASE SHARES....................................................  26
SHAREHOLDER SERVICES......................................................  29
HOW TO REDEEM SHARES......................................................  29
CALCULATION OF PERFORMANCE INFORMATION....................................  31
DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES...........................  31
</TABLE>    
 
                                       2
<PAGE>
 
                              SUMMARY OF EXPENSES
               (FOR A RETAIL CLASS SHARE OF EACH INDICATED FUND)
   
  The following information is provided as an aid in understanding the various
expenses that an investor in a Fund will bear indirectly. The information
below is based on expenses for the Funds' most recent fiscal year ended, and
should not be considered a representation of past or future expenses, as actual
expenses may be greater or less than those shown. Also, the 5% annual return
assumed in the Example should not be considered a representation of investment
performance, as actual performance will vary.     
 
<TABLE>   
<CAPTION>
                                   CORE      INTERNATIONAL MID-CAP    MID-CAP
                                   VALUE        EQUITY     GROWTH      VALUE
                                   FUND          FUND       FUND       FUND
                                   -----     ------------- -------    -------
<S>                                <C>       <C>           <C>        <C>
Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on
  Purchases (as % of offering
  price).......................... none          none       none       none
 Maximum Sales Load Imposed on
  Reinvested Dividends (as % of
  (offering price)................ none          none       none       none
 Maximum Deferred Sales Load
  (as % of original purchase price
  or redemption proceeds)......... none          none       none       none
 Redemption Fees/1............./.. none          none       none       none
 Exchange Fees.................... none          none       none       none
Annual Fund Operating Expenses
 (as a percentage of average
 net assets):
 Management Fees..................  .50%          .75%       .75%       .75%
 12b-1 Fees.......................  .25%          .25%       .25%       .25%
 Other Operating Expenses (after
  expense reimbursements where
  indicated)......................  .35%/2/       .25%/2/    .25%/2/    .25%/2/
 Total Fund Operating Expenses
  (after expense reimbursements
  where indicated)................ 1.10%/2/      1.25%/2/   1.25%/2/   1.25%/2/
Example:
An investor would pay the
 following expenses on a $1,000
 investment assuming a 5% annual
 return (with or without a
 redemption at the end of each
 time period):
 One Year......................... $ 11          $ 13       $ 13       $ 13
 Three Years...................... $ 35          $ 40       $ 40       $ 40
 Five Years....................... $ 61          $ 69       $ 69       $ 69
 Ten Years........................ $134          $151       $151       $151
</TABLE>    
 
                                       3
<PAGE>
 
<TABLE>   
<CAPTION>
                                    SMALL CAP     SMALL   STRATEGIC
                                     GROWTH     CAP VALUE   VALUE     WORLDWIDE
                                      FUND        FUND      FUND        FUND
                                    ---------   --------- ---------   ---------
<S>                                 <C>         <C>       <C>         <C>
Shareholder Transactions Expenses:
 Maximum Sales Load Imposed on
  Purchases (as % of offering
  price)..........................    none        none      none        none
 Maximum Sales Load Imposed on
  Reinvested Dividends
  (as % of offering price)........    none        none      none        none
 Maximum Deferred Sales Load
  (as % of original purchase price
  or redemption proceeds).........    none        none      none        none
 Redemption Fees/1............./..    none        none      none        none
 Exchange Fees....................    none        none      none        none
Annual Fund Operating Expenses
 (as a percentage of average
 net assets):
 Management Fees..................     .75%        .75%      .50%        .75%
 12b-1 Fees.......................     .25%        .25%      .25%        .25%
 Other Operating Expenses (after
  expense reimbursements where
  indicated)......................     .25%/2/     .19%      .50%/2/     .25%/2/
 Total Fund Operating Expenses
  (after expense reimbursements
  where indicated)................    1.25%/2/    1.19%     1.25%/2/    1.25%/2/
Example:
An investor would pay the
 following expenses on a $1,000
 investment assuming a 5% annual
 return (with or without a
 redemption at the end of each
 time period):
 One Year.........................    $ 13        $ 12      $ 13        $ 13
 Three Years......................    $ 40        $ 38      $ 40        $ 40
 Five Years.......................    $ 69        $ 65      $ 69        $ 69
 Ten Years........................    $151        $144      $151        $151
</TABLE>    
- -----------
/1/A $5 charge applies to any wire transfer of redemption proceeds from any
   Fund.
   
/2/Loomis Sayles has voluntarily agreed, for an indefinite period, to limit
   the Funds' Total Operating Expenses to the percentages of net assets shown
   in the table. Without this agreement, Other Operating Expenses (including 
   12b-1 fees) and Total Operating Expenses would have been 1.7% and 2.20%,
   respectively, for the Core Value Fund, 9.51% and 10.26%, respectively, for
   the International Equity Fund, 27.22% and 27.97%, respectively, for the Mid-
   Cap Growth Fund, 12.56% and 13.31%, respectively, for the Mid-Cap Value Fund,
   2.95% and 3.70%, respectively, for the Small Cap Growth Fund, 14.96% and
   15.46%, respectively, for the Strategic Value Fund and 23.94% and 24.69%,
   respectively, for the Worldwide Fund. Other Operators Expenses and Total
   Operating Expenses for the Small Cap Value Fund were unaffected by this
   Agreement.     
 
                                       4
<PAGE>
 
                             FINANCIAL HIGHLIGHTS
               (FOR A RETAIL CLASS SHARE OF EACH INDICATED FUND
                 OUTSTANDING THROUGHOUT THE INDICATED PERIODS)
   
  The financial highlights tables that follow have been audited by
PricewaterhouseCoopers LLP, independent accountants. The information should be
read in conjunction with the financial highlights, financial statements and
the notes thereto contained in the Funds' 1998 Annual Report, which is
incorporated by reference in this Prospectus and the Statement of Additional
Information.     
 
<TABLE>   
<CAPTION>
                                                         CORE VALUE FUND
                                                     -----------------------
                                                      NINE MONTHS   JAN. 2**
                                                         ENDED         TO
                                                     SEPTEMBER 30*, DEC. 31,
                                                          1998        1997
                                                     -------------- --------
 <S>                                                 <C>            <C>
 Net asset value, beginning of period................    $17.62      $15.60
                                                         ------      ------
 Income from investment operations--
   Net investment income (loss)......................      0.15***     0.15***
   Net realized and unrealized gain (loss)
    on investments...................................     (0.98)       4.30
                                                         ------      ------
    Total from investment operations.................   (0.83)       4.45
                                                         ------      ------
 Less distributions--
   Dividends from net investment income..............      0.00       (0.16)
   Distributions from net realized capital gains.....      0.00       (2.27)
                                                         ------      ------
    Total distributions..............................      0.00       (2.43)
                                                         ------      ------
 Net asset value, end of period......................    $16.79      $17.62
                                                         ======      ======
 Total return (%)****................................      (4.7)       28.9
 Net assets, end of period (000).....................    $1,015      $1,324
 Ratio of operating expenses to average net
  assets (%)+........................................      1.10++      1.10++
 Ratio of net investment income to average net
  assets (%).........................................      1.07++      0.84++
 Portfolio turnover rate (%).........................        49+++       64
 Without giving effect to voluntary expense
  limitations:
   The ratios of operating expenses to average net
    assets would have been (%).......................      2.20++      6.17++
   Net investment income per share would have been...    $ 0.00***   $(0.73)***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   + The advisor has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.
  ++ Computed on an annualized basis.
   
 +++  Periods less than one year are not annualized.     
 
                                       5
<PAGE>
 
<TABLE>   
<CAPTION>
                                              INTERNATIONAL EQUITY FUND
                                           --------------------------------
                                             NINE MONTHS          JAN. 2**
                                                ENDED                TO
                                           SEPTEMBER 30*,         DEC. 31,
                                                1998                1997
                                           ---------------     ------------
 <S>                                       <C>                 <C>
 Net asset value, beginning of period...      $      11.28     $      13.16
                                              ------------     ------------
 Income from investment operations--
   Net investment income (loss).........              0.10             0.10 ***
   Net realized and unrealized gain     
    (loss) on investments...............             (0.68)           (0.26)
                                              ------------     ------------
    Total from investment operations....             (0.58)           (0.16)
                                              ------------     ------------
 Less distributions--
   Dividends from net investment income.              0.00            (0.17)
   Distributions from net realized      
    capital gains.......................              0.00            (1.55)
                                              ------------     ------------
    Total distributions.................              0.00            (1.72)
                                              ------------     ------------
 Net asset value, end of period.........      $      10.70     $      11.28
                                              ============     ============
 Total return (%)****...................              (5.1)+++         (1.3)
 Net assets, end of period (000)........      $        150     $        233
 Ratio of operating expenses to average
  net assets (%)+.......................              1.25 ++          1.25 ++
 Ratio of net investment income to
  average net assets (%)................              1.16 ++          0.73 ++
 Portfolio turnover rate (%)............                96 +++          119
 Without giving effect to voluntary
  expense limitations:
   The ratios of operating expenses to
    average net assets would have been
    (%).................................             10.26 ++         16.24 ++
   Net investment income per share would
    have been...........................      $      (0.67)    $      (1.93)***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   + The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.
  ++ Computed on an annualized basis.
    
 +++ Periods less than one year are not annualized.     

                                       6
<PAGE>
 
<TABLE>   
<CAPTION>
                                                        MID-CAP GROWTH  FUND
                                                       -----------------------
                                                        NINE MONTHS   JAN. 2**
                                                           ENDED         TO
                                                       SEPTEMBER 30*, DEC. 31,
                                                            1998        1997
                                                       -------------- --------
 <S>                                                   <C>            <C>
 Net asset value, beginning of period................      $11.49      $10.00
                                                           ------      ------
 Income from investment operations--
   Net investment income (loss)......................       (0.05)      (0.06)
   Net realized and unrealized gain (loss)           
    on investments...................................       (0.95)       2.27
                                                           ------      ------
    Total from investment operations.................       (1.00)       2.21
                                                           ------      ------
 Less distributions--
   Distributions in excess of net investment income..        0.00       (0.10)
   Distributions from net realized capital gains.....        0.00       (0.62)
                                                           ------      ------
    Total distributions..............................        0.00       (0.72)
                                                           ------      ------
 Net asset value, end of period......................      $10.49      $11.49
                                                           ======      ======
 Total return (%)***.................................        (8.7)++     22.4
 Net assets, end of period (000).....................      $   85      $   74
 Ratio of operating expenses to average net
  assets (%)****.....................................        1.25 +      1.25 +
 Ratio of net investment income to average net assets
  (%)................................................       (0.60)+     (0.67)+
 Portfolio turnover rate (%).........................          82 ++      174
 Without giving effect to voluntary expense
  limitations:
   The ratios of operating expenses to average net
    assets would have been (%).......................       27.97 +     36.58 +
   Net investment income per share would have been...      $(2.08)     $(3.29)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
     
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
    
  ++ Periods less than one year are not annualized.     
 
                                       7
<PAGE>
 
<TABLE>   
<CAPTION>
                                                         MID-CAP VALUE FUND
                                                       -----------------------
                                                        NINE MONTHS   JAN. 2**
                                                           ENDED         TO
                                                       SEPTEMBER 30*, DEC. 31,
                                                            1998        1997
                                                       -------------- --------
 <S>                                                   <C>            <C>
 Net asset value, beginning of period................      $11.53      $10.00
                                                           ------      ------
 Income from investment operations--
   Net investment income (loss)......................       (0.01)       0.03
   Net realized and unrealized gain (loss) 
    on investments...................................       (1.45)       2.55
                                                           ------      ------
    Total from investment operations.................       (1.46)       2.58
                                                           ------      ------
 Less distributions--
   Dividends from net investment income..............        0.00       (0.11)
   Distributions from net realized capital gains.....        0.00       (0.94)
                                                           ------      ------
    Total distributions..............................        0.00       (1.05)
                                                           ------      ------
 Net asset value, end of period......................      $10.07      $11.53
                                                           ======      ======
 Total return (%)***.................................       (12.7)++     26.0
 Net assets, end of period (000).....................      $  121      $  168
 Ratio of operating expenses to average net
  assets (%)****.....................................        1.25+       1.25 +
 Ratio of net investment income to average net assets
  (%)................................................       (0.03)+      0.42 +
 Portfolio turnover rate (%).........................         225 ++      130
 Without giving effect to voluntary expense
  limitations:
   The ratios of operating expenses to average net
    assets would have been (%).......................       13.31+      27.99 +
   Net investment income per share would have been...      $(2.40)     $(1.90)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
    
  ++ Periods less than one year are not annualized.     
 
                                       8
<PAGE>
 
<TABLE>   
<CAPTION>
                                                      SMALL CAP GROWTH FUND
                                                     -----------------------
                                                      NINE MONTHS   JAN. 2**
                                                         ENDED         TO
                                                     SEPTEMBER 30*, DEC. 31,
                                                          1998        1997
                                                     -------------- --------
 <S>                                                 <C>            <C>
 Net asset value, beginning of period..............      $11.30      $10.00
                                                         ------      ------
 Income from investment operations--
   Net investment income (loss)....................       (0.08)      (0.10)***
   Net realized and unrealized gain (loss)  
    on investments.................................       (1.42)       1.99
                                                         ------      ------
    Total from investment operations...............       (1.50)       1.89
                                                         ------      ------
 Less distributions--
   Distributions in excess of net realized capital
    gains..........................................        0.00       (0.59)
                                                         ------      ------
    Total distributions............................        0.00       (0.59)
                                                         ------      ------
 Net asset value, end of period....................      $ 9.80      $11.30
                                                         ======      ======
 Total return (%)****..............................       (13.3)+++    19.2
 Net assets, end of period (000)...................      $1,057      $1,139
 Ratio of operating expenses to average net
  assets (%)+......................................        1.25 ++     1.25 ++
 Ratio of net investment income to average net
  assets (%).......................................       (0.80)++    (0.94)++
 Portfolio turnover rate (%).......................         116 +++     211
 Without giving effect to voluntary expense
  limitations:
   The ratios of operating expenses to average net
    assets would have been (%).....................        3.70 ++     7.82 ++
   Net investment income per share would have been.      $(0.34)     $(0.77)***
</TABLE>    
- -----------
   
   *  The Fund's fiscal year-end changed to September 30 from December 31.      
      
   
  **  Commencement of investment operations.     
   
 ***  Per share net investment income has been determined on the basis of the
      weighted average number of shares outstanding during the period.     
    
****  Total returns would have been lower had the adviser not reduced its
      advisory fee and/or borne other operating expenses.     
   +  The adviser has agreed to reimburse a portion of the Fund's expenses
      during the period. Without the reimbursement the Fund's ratio of
      operating expenses would have been higher.
  ++  Computed on an annualized basis.
    
 +++  Periods less than one year are not annualized.     

                                       9

<PAGE>
 
<TABLE>   
<CAPTION>
                                                      SMALL CAP VALUE FUND
                                                     -----------------------
                                                      NINE MONTHS   JAN 2**
                                                         ENDED         TO
                                                     SEPTEMBER 30*, DEC. 31,
                                                          1998        1997
                                                     -------------- --------
 <S>                                                 <C>            <C>
 Net asset value, beginning of period..............     $ 18.62     $ 17.39
                                                        -------     -------
 Income from investment operations--
   Net investment income (loss)....................        0.10        0.15***
   Net realized and unrealized gain (loss)  
    on investments.................................       (3.15)       4.21
                                                        -------     -------
    Total from investment operations...............       (3.05)       4.36
                                                        -------     -------
 Less distributions--
   Dividends from net investment income............        0.00       (0.08)
   Distributions from net realized capital gains...        0.00       (3.05)
                                                        -------     -------
    Total distributions............................        0.00       (3.13)
                                                        -------     -------
 Net asset value, end of period....................     $ 15.57      $18.62
                                                        =======     =======
 Total return (%)****..............................       (16.4)+++    25.6
 Net assets, end of period (000)...................     $54,060     $34,353
 Ratio of operating expenses to average net
  assets (%)+......................................        1.19++      1.25++
 Ratio of net investment income to average net
  assets (%).......................................        0.79++      0.79++
 Portfolio turnover rate (%).......................          78+++       94
 Without giving effect to voluntary expense
  limitations:
   The ratios of operating expenses to average net
    assets would have been (%).....................        1.19++      1.35++
   Net investment income per share would have been.     $  0.10     $  0.13***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   + The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.
  ++ Computed on an annualized basis.
    
+++  Periods less than one year are not annualized.      
 
                                      10
<PAGE>
 
<TABLE>   
<CAPTION>
                                                      STRATEGIC VALUE FUND
                                                     -----------------------
                                                      NINE MONTHS   JAN 2**
                                                         ENDED         TO
                                                     SEPTEMBER 30*, DEC. 31,
                                                          1998        1997
                                                     -------------- --------
 <S>                                                 <C>            <C>
 Net asset value, beginning of period................    $11.76      $10.00
                                                         ------      ------
 Income from investment operations--
   Net investment income (loss)......................     (0.04)      (0.06)***
   Net realized and unrealized gain (loss)
    on investments...................................     (1.27)       2.00
                                                         ------      ------
    Total from investment operations.................     (1.31)       1.94
                                                         ------      ------
 Less distributions--
   Distributions in excess of net investment
    income...........................................      0.00       (0.18)
                                                         ------      ------
    Total distributions..............................      0.00       (0.18)
                                                         ------      ------
 Net asset value, end of period......................    $10.45      $11.76
                                                         ======      ======
 Total return (%)****................................     (11.1)+++    19.4
 Net assets, end of period (000).....................    $  249      $  279
 Ratio of operating expenses to average net
  assets (%)+........................................      1.25 ++     1.25 ++
 Ratio of net investment income to average net
  assets (%).........................................     (0.47)++    (0.49)++
 Portfolio turnover rate (%).........................        31+++       34
 Without giving effect to voluntary expense
  limitations:
   The ratios of operating expenses to average net
    assets would have been (%).......................     15.46 ++    21.33 ++
   Net investment income per share would have been...    $(1.38)     $(2.50)***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   + The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.
  ++ Computed on an annualized basis.
    
+++  Periods less than one year are not annualized.      
 
                                      11
<PAGE>
 
<TABLE>   
<CAPTION>
                                                       WORLDWIDE FUND
                                                   ------------------------
                                                    NINE MONTHS    JAN. 2**
                                                       ENDED          TO
                                                   SEPTEMBER 30*,  DEC. 31,
                                                        1998         1997
                                                   --------------  --------
 <S>                                               <C>             <C>
 Net asset value, beginning of period..............   $  9.86      $  10.63
                                                      -------      --------
 Income from investment operations--
   Net investment income (loss)....................      0.30***       0.38***
   Net realized and unrealized gain (loss) on
    investments....................................     (1.40)        (0.03)
                                                      -------      --------
    Total from investment operations...............     (1.10)         0.35
                                                      -------      --------
 Less distributions--
   Dividends from net investment income............      0.00         (0.45)
   Distributions from net realized capital gains...      0.00         (0.67)
                                                      -------      --------
    Total distributions............................      0.00         (1.12)
                                                      -------      --------
 Net asset value, end of period....................   $  8.76      $   9.86
                                                      =======      ========
 Total return (%)****..............................     (11.2)+++       3.3
 Net assets, end of period (000)...................   $    73      $     20
 Ratio of operating expenses to average net
  assets (%)+......................................      1.25++        1.25++
 Ratio of net investment income to average net
  assets (%).......................................      3.88++        3.58++
 Portfolio turnover rate (%).......................        93+++        134
 Without giving effect to voluntary expense
  limitations:
   The ratios of operating expenses to average net
    assets would have been (%).....................       24.69++      214.91++
   Net investment income per share would have
    been...........................................     $ (1.49)***  $ (23.33)***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns wold have been lower had the advisor not reduced its
     advisory fee and/or borne other operating expenses.     
   + The advisor has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.
  ++ Computed on an annualized basis.
     
 +++ Periods less than one year are not annualized.     


NOTE:  Further information about each Fund's performance is contained in the
       Funds' annual report to shareholders, which may be obtained without
       charge.
 
                                      12
<PAGE>
 
                                   THE TRUST
 
  Each Fund is a series of Loomis Sayles Funds (the "Trust"). The Trust is a
diversified open-end management investment company organized as a
Massachusetts business trust on February 20, 1991. The Trust is authorized to
issue an unlimited number of full and fractional shares of beneficial interest
in multiple series. Shares are freely transferable and entitle shareholders to
receive dividends as determined by the Trust's board of trustees and to cast a
vote for each share held at shareholder meetings. The Trust does not generally
hold shareholder meetings and will do so only when required by law.
Shareholders may call meetings to consider removal of the Trust's trustees.
 
                      INVESTMENT OBJECTIVES AND POLICIES
 
LOOMIS SAYLES CORE VALUE FUND
 
  The Fund's investment objective is long-term growth of capital and income.
   
  The Fund seeks to achieve its objective by investing substantially all of
its assets in common stocks or their equivalent that Loomis Sayles considers
to be undervalued in relation to the issuer's earnings, dividends, assets and
growth prospects. The Fund may invest up to 20% of its total assets in
securities of foreign issuers. The Fund may also engage in foreign currency
hedging transactions real estate investment trusts ("REITs") and Rule 144A
securities.     
       
LOOMIS SAYLES INTERNATIONAL EQUITY FUND
 
  The Fund's investment objective is high total investment return through a
combination of capital appreciation and current income.
   
  The Fund seeks to achieve its objective by investing primarily in equity
securities of companies organized or headquartered outside the United States.
Under normal conditions the Fund will invest at least 65% of its total assets
in equity securities of issuers from at least three countries outside the
United States. For temporary defensive purposes, the Fund may invest as much
as 100% of its total assets in issuers from one or two countries, which may
include the United States. The Fund may also engage in foreign currency
hedging transactions, options transactions, REITs and Rule 144A securities.
    
LOOMIS SAYLES MID-CAP GROWTH FUND
 
  The Fund's investment objective is long-term capital growth from investments
in common stocks or their equivalent.
 
                                      13
<PAGE>
 
   
  The Fund seeks to achieve its objective by investing, under normal market
conditions, at least 65% of its total assets in equity securities of companies
with a market capitalization that falls within the capitalization range of
companies included in the Standard & Poor's Mid-Cap 400 Index. Current income
is not a consideration in selecting the Fund's investments. The Fund may
invest any portion of its assets in securities of Canadian issuers and up to
20% of its total assets in the securities of issuers headquartered outside the
United States or Canada. The Fund may also engage in foreign currency hedging
transactions, options and futures transactions, securities lending, and Rule
144A securities.     
 
LOOMIS SAYLES MID-CAP VALUE FUND
 
  The Fund's objective is long-term capital growth from investments in common
stocks or their equivalent.
   
  The Fund seeks to achieve its objective by investing, under normal market
conditions, at least 65% of its total assets in equity securities of companies
with a market capitalization that falls within the capitalization range of
companies included in the Standard & Poor's Mid-Cap 400 Index. Loomis Sayles
seeks to build a core portfolio of equity securities that it believes to be
undervalued by the market in relation to the issuers' earnings, dividends,
assets and growth prospects and that has a smaller emphasis on special
situations and turnarounds (companies that have experienced significant
business problems but that Loomis Sayles believes have favorable prospects for
recovery). Current income is not a consideration in selecting the Fund's
investments. The Fund may invest any portion of its assets in securities of
Canadian issuers and up to 20% of its total assets in the securities of
issuers headquartered outside the United States or Canada. The Fund may also
engage in foreign currency hedging transactions, options and futures
transactions, securities lending, REITs and Rule 144A securities.     
 
LOOMIS SAYLES SMALL CAP GROWTH FUND
 
  The Fund's investment objective is long-term capital growth from investments
in common stocks or their equivalent.
   
  The Fund seeks to achieve its objective by investing primarily in equity
securities of small, rapidly growing companies that Loomis Sayles believes
have the potential for accelerating earnings growth and rising profit margins.
The Fund will normally invest at least 65% of its total assets in equity
securities of companies with market capitalizations that fall within the
capitalization range of the Russell 2000 Index and may invest up to 35% of its
total assets in larger companies. Loomis Sayles seeks companies that have
distinctive products, technologies, or services; dynamic earnings growth;
prospects for a high level of profitability; and outstanding management.
Current income is not a consideration in selecting the Fund's investments. The
Fund may invest any     
 
                                      14
<PAGE>
 
   
portion of its assets in securities of Canadian issuers and up to 20% of its
total assets in the securities of issuers headquartered outside the United
States or Canada. The Fund may also engage in foreign currency hedging
transactions, options and futures transactions, securities lending, and Rule
144A securities.     
 
LOOMIS SAYLES SMALL CAP VALUE FUND
 
  The Fund's investment objective is long-term capital growth from investments
in common stocks or their equivalent.
   
  The Fund seeks to achieve its objective by investing primarily in equity
securities of small capitalization companies with good earnings growth
potential that Loomis Sayles believes are undervalued by the markets. The Fund
will normally invest at least 65% of its total assets in equity securities of
companies with market capitalizations that fall within the capitalization
range of the Russell 2000 Index and may invest up to 35% of its total assets
in larger companies. Loomis Sayles seeks to build a core small capitalization
portfolio of stocks of solid companies with reasonable growth prospects and
that are attractively priced in relation to the companies' earnings with a
smaller emphasis on special situations and turnarounds (companies that have
experienced significant business problems but which Loomis Sayles believes
have favorable prospects for recovery), as well as unrecognized stocks.
Current income is not a consideration in selecting the Fund's investments. The
Fund may invest up to 20% of its total assets in securities of foreign
issuers. The Fund may also engage in foreign currency hedging transactions,
REITs and Rule 144A securities.     
 
LOOMIS SAYLES STRATEGIC VALUE FUND
 
  The Fund's investment objective is long-term capital growth from investments
in equity securities.
   
  The Fund seeks to achieve its objective by investing substantially all of
its assets in equity securities that Loomis Sayles considers to be undervalued
by the markets. Stocks are selected based on a combination of quantitative
factors including historical, relative price-earnings ratios; price-earnings
ratios relative to growth rates; relative fundamentals and price momentum; and
qualitative factors including the quality of management, position in the
industry, debt and balance sheet restructuring and product cycles. The Fund's
strategy is to have a relatively concentrated portfolio normally consisting of
approximately 35-40 securities that Loomis Sayles considers best positioned to
perform in the current and future environments. The Fund may invest any
portion of its assets in the securities of Canadian issuers and up to 20% of
its total assets in securities of issuers headquartered outside the United
States or Canada. The Fund may also engage in foreign currency hedging
transactions, options and futures transactions, securities lending, REITs and
Rule 144A securities.     
 
                                      15
<PAGE>
 
LOOMIS SAYLES WORLDWIDE FUND
 
  The Fund's investment objective is high total investment return through a
combination of capital appreciation and current income.
   
  The Fund seeks to achieve its objective by investing in U.S. and foreign
equity and debt securities. The allocation of the Fund's assets among the four
sectors of domestic equities, international equities, domestic bonds and
international bonds will be made by Loomis Sayles' Global Asset Allocation
group. The Fund will normally invest its assets in securities of issuers from
at least three countries, one of which may be the United States. The Fund may
also invest in collateralized mortgage obligations, zero coupon securities,
when-issued securities, REITs and Rule 144A securities. The Fund may engage in
foreign currency hedging transactions and options and forward contract
transactions.     
 
ALL FUNDS
 
  For temporary defensive purposes, each Fund may invest any portion of its
assets in fixed income securities, cash and any other securities deemed
appropriate by Loomis Sayles. Except for each Fund's investment objective, and
any investment policies that are identified as "fundamental," all of the
investment policies of each Fund may be changed without a vote of Fund
shareholders.
 
                 MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS
                            AND RISK CONSIDERATIONS
 
COMMON STOCKS AND OTHER EQUITY SECURITIES
 
  Common stocks and similar equity securities, such as warrants and
convertibles, are volatile and more risky than some other forms of investment.
The value of an investment in a Fund that invests in equity securities may
sometimes decrease. Equity securities of companies with relatively small
market capitalization may be more volatile than the securities of larger, more
established companies and than the broad equity market indexes.
 
DEBT AND OTHER FIXED INCOME SECURITIES
 
  The Worldwide Fund may invest in fixed income securities of any maturity.
Fixed income securities pay a specified rate of interest or dividends, or a
rate that is adjusted periodically by reference to some specified index or
market rate. Fixed income securities include securities issued by federal,
state, local and foreign governments and related agencies, and by a wide range
of private issuers. Because interest rates vary, it is impossible to predict
the yield of a Fund that invests in fixed income securities for any particular
period. The net asset
 
                                      16
<PAGE>
 
value of such a Fund's shares will vary as a result of changes in the value of
the securities in the Fund's portfolio.
 
  Fixed income securities are subject to market and credit risk. Market risk
relates to changes in a security's value as a result of changes in interest
rates generally. In general, the values of fixed income securities increase
when prevailing interest rates fall and decrease when interest rates rise.
Credit risk relates to the ability of the issuer to make payments of principal
and interest.
 
ZERO COUPON SECURITIES
 
  The Worldwide Fund may invest in "zero coupon" fixed income securities.
These securities accrue interest at a specified rate, but do not pay interest
in cash on a current basis. A Fund investing in zero coupon securities is
required to distribute the income on these securities to Fund shareholders as
the income accrues, even though the Fund is not receiving the income in cash
on a current basis. Thus the Fund may have to sell other investments to obtain
cash to make income distributions. The market value of zero coupon securities
is often more volatile than that of non-zero coupon fixed income securities of
comparable quality and maturity.
 
COLLATERALIZED MORTGAGE OBLIGATIONS
 
  The Worldwide Fund may invest in collateralized mortgage obligations
("CMOs"). A CMO is a security backed by a portfolio of mortgages or mortgage-
backed securities held under an indenture. CMOs may be issued either by U.S.
Government instrumentalities or by non-governmental entities. The issuer's
obligation to make interest and principal payments is secured by the
underlying portfolio of mortgages or mortgage-backed securities. CMOs are
issued with a number of classes or series which have different maturities and
which may represent interests in some or all of the interest or principal
payments on the underlying collateral or a combination thereof. CMOs of
different classes are generally retired in sequence as the underlying mortgage
loans in the mortgage pool are repaid. In the event of sufficient early
prepayments on such mortgages, the class or series of CMOs first to mature
generally will be retired prior to its maturity. As with other mortgage-backed
securities, the early retirement of a particular class or series of CMOs held
by a Fund could involve the loss of any premium the Fund paid when it acquired
the investment and could result in the Fund's reinvesting the proceeds at a
lower interest rate than the retired CMO paid. Because of the early retirement
feature, CMOs may be more volatile than many other fixed-income investments.
 
WHEN-ISSUED SECURITIES
 
  Each Fund may purchase securities on a "when-issued" basis. This means that
the Fund will enter into a commitment to buy the security before the
 
                                      17
<PAGE>
 
security has been issued. The Fund's payment obligation and the interest rate
on the security are determined when the Fund enters into the commitment. The
security is typically delivered to the Fund 15 to 120 days later. No interest
accrues on the security between the time the Fund enters into the commitment
and the time the security is delivered. If the value of the security being
purchased falls between the time a Fund commits to buy it and the payment
date, the Fund may sustain a loss. The risk of this loss is in addition to the
Fund's risk of loss on the securities actually in its portfolio at the time.
In addition, when the Fund buys a security on a when-issued basis, it is
subject to the risk that market rates of interest will increase before the
time the security is delivered, with the result that the yield on the security
delivered to the Fund may be lower than the yield available on other,
comparable securities at the time of delivery. If a Fund has outstanding
obligations to buy when-issued securities, it will maintain liquid assets in a
segregated account at its custodian bank in an amount sufficient to satisfy
these obligations.
   
REAL ESTATE INVESTMENT TRUSTS     
   
  The Funds may invest in REITs. REITs involve certain unique risks in
addition to those risks associated with investing in the real estate industry
in general (such as possible declines in the value of real estate, lack of
availability of mortgage funds or extended vacancies of property). Equity
REITs may be affected by changes in the value of the underlying property owned
by the REITs, while mortgage REITs may be affected by the quality of any
credit extended. REITs are dependent upon management skills, are not
diversified, are subject to heavy cash flow dependency, risks of default by
borrowers and self-liquidation. REITs are also subject to the possibilities of
failing to qualify for tax-free pass-through of income under the Code, and
failing to maintain their exemptions from registration under the Investment
Company Act of 1940 (the "1940 Act").     
   
  Investment in REITs involves risk similar to those associated with investing
in small capitalization companies. REITs may have limited financial resources,
may trade less frequently and in a limited volume and may be subject to more
abrupt or erratic price movements than larger securities.     
       
RULE 144A SECURITIES
 
  Each Fund may invest in Rule 144A securities, which are privately offered
securities that can be resold only to certain qualified institutional buyers.
Rule 144A securities are treated as illiquid, unless Loomis Sayles has
determined, under guidelines established by the Trust's trustees, that the
particular issue of Rule 144A securities is liquid.
 
 
                                      18
<PAGE>
 
FOREIGN SECURITIES
   
  Each Fund may invest in securities of issuers organized or headquartered
outside the United States ("foreign securities"). Each of the Core Value and
Small Cap Value Funds will not purchase a foreign security if, as a result,
the Fund's holdings of foreign securities would exceed 20% of the Fund's total
assets. Each of the Mid-Cap Growth, Mid-Cap Value, Small Cap Growth and
Strategic Value Funds may each invest any portion of its assets in securities
of Canadian issuers, but will not purchase foreign securities other than those
of Canadian issuers if, as a result, such Fund's holding of non-U.S. and non-
Canadian securities would exceed 20% of the Fund's total assets.     
 
  Although investing in foreign securities may increase a Fund's
diversification and reduce portfolio volatility, foreign securities may
present risks not associated with investments in comparable securities of U.S.
issuers. There may be less information publicly available about a foreign
corporate or governmental issuer than about a U.S. issuer, and foreign
corporate issuers are not generally subject to accounting, auditing and
financial reporting standards and practices comparable to those in the United
States. The securities of some foreign issuers are less liquid and at times
more volatile than securities of comparable U.S. issuers. Foreign brokerage
commissions and securities custody costs are often higher than in the United
States. With respect to certain foreign countries, there is a possibility of
governmental expropriation of assets, confiscatory taxation, political or
financial instability and diplomatic developments that could affect the value
of investments in those countries. A Fund's receipt of interest on foreign
government securities may depend on the availability of tax or other revenues
to satisfy the issuer's obligations.
 
  A Fund's investments in foreign securities may include investments in
countries whose economies or securities markets are not yet highly developed.
Special considerations associated with these investments (in addition to the
considerations regarding foreign investments generally) may include, among
others, greater political uncertainties, an economy's dependence on revenues
from particular commodities or on international aid or development assistance,
currency transfer restrictions, highly limited numbers of potential buyers for
such securities and delays and disruptions in securities settlement
procedures.
 
  Since most foreign securities are denominated in foreign currencies or
traded primarily in securities markets in which settlements are made in
foreign currencies, the value of these investments and the net investment
income available for distribution to shareholders of a Fund investing in these
securities may be affected favorably or unfavorably by changes in currency
exchange rates, exchange control regulations or foreign withholding taxes.
Changes in the value relative to the U.S. dollar of a foreign currency in
which a Fund's holdings are denominated will result in a change in the U.S.
dollar value of the Fund's assets and the Fund's income available for
distribution.
 
                                      19
<PAGE>
 
  In addition, although part of a Fund's income may be received or realized in
foreign currencies, the Fund will be required to compute and distribute its
income in U.S. dollars. Therefore, if the value of a currency relative to the
U.S. dollar declines after the Fund's income has been earned in that currency,
translated into U.S. dollars and declared as a dividend, but before payment of
the dividend, the Fund could be required to liquidate portfolio securities to
pay the dividend. Similarly, if the value of a currency relative to the U.S.
dollar declines between the time the Fund accrues expenses in U.S. dollars and
the time such expenses are paid, the amount of such currency required to be
converted into U.S. dollars will be greater than the equivalent amount in such
currency of such expenses at the time they were incurred.
 
  In determining whether to invest assets of a Fund in securities of a
particular foreign issuer, Loomis Sayles will consider the likely effects of
foreign taxes on the net yield available to the Fund and its shareholders.
Compliance with foreign tax law may reduce a Fund's net income available for
distribution to shareholders.
 
FOREIGN CURRENCY HEDGING TRANSACTIONS
 
  Each Fund that invests in foreign securities may engage in foreign currency
exchange transactions, in connection with the purchase and sale of foreign
securities, to protect the value of specific portfolio positions or in
anticipation of changes in relative values of currencies in which current or
future Fund portfolio holdings are denominated or quoted. For example, to
protect against a change in the foreign currency exchange rate between the
date on which a Fund contracts to purchase or sell a security and the
settlement date for the purchase or sale, or to "lock in" the equivalent of a
dividend or interest payment in another currency, a Fund might purchase or
sell a foreign currency on a spot (that is, cash) basis at the prevailing spot
rate. If conditions warrant, the Funds may also enter into private contracts
to purchase or sell foreign currencies at a future date ("forward contracts").
The Funds might also purchase exchange-listed and over-the-counter call and
put options on foreign currencies. Over-the-counter currency options are
generally less liquid than exchange-listed options, and will be treated as
illiquid assets. The Funds may not be able to dispose of over-the-counter
options readily.
 
  Foreign currency transactions involve costs and may result in losses.
 
OPTIONS AND FUTURES TRANSACTIONS
 
  The International Equity, Mid-Cap Growth, Mid-Cap Value, Small Cap Growth,
Strategic Value and Worldwide Funds may buy, sell or write options on
securities, securities indexes, currencies or futures contracts. The Mid-Cap
Growth, Mid-Cap Value, Small Cap Growth and Strategic Value Funds may buy
 
                                      20
<PAGE>
 
and sell futures contracts on securities, securities indexes or currencies.
Each of these Funds may engage in these transactions either for the purpose of
enhancing investment return, or to hedge against changes in the value of other
assets that the Fund owns or intends to acquire. Options and futures fall into
the broad category of financial instruments known as "derivatives" and involve
special risks. Use of options or futures for other than hedging purposes may
be considered a speculative activity, involving greater risks than are
involved in hedging.
 
  Options can generally be classified as either "call" or "put" options. There
are two parties to a typical options transaction: the "writer" and the
"buyer." A call option gives the buyer the right to buy a security or other
asset (such as an amount of currency or a futures contract) from, and a put
option gives the buyer the right to sell a security or other asset to, the
option writer at a specified price, on or before a specified date. The buyer
of an option pays a premium when purchasing the option, which reduces the
return on the underlying security or other asset if the option is exercised,
and results in a loss if the option expires unexercised. The writer of an
option receives a premium from writing an option, which may increase its
return if the option expires or is closed out at a profit. If a Fund as the
writer of an option is unable to close out an unexpired option, it must
continue to hold the underlying security or other asset until the option
expires, to "cover" its obligation under the option.
 
  A futures contract creates an obligation by the seller to deliver and the
buyer to take delivery of the type of instrument or cash at the time and in
the amount specified in the contract. Although many futures contracts call for
the delivery (or acceptance) of the specified instrument, futures are usually
closed out before the settlement date through the purchase (or sale) of a
comparable contract. If the price of the sale of the futures contract by a
Fund exceeds (or is less than) the price of the offsetting purchase, the Fund
will realize a gain (or loss). The value of options purchased or written by a
Fund and futures contracts held by a Fund may fluctuate based on a variety of
market and economic factors. In some cases, the fluctuations may offset (or be
offset by) changes in the value of securities held in a Fund's portfolio. All
transactions in options and futures involve the possible risk of loss to a
Fund of all or a significant part of the value of its investment. In some
cases, the risk of loss may exceed the amount of the Fund's investment. When a
Fund writes a call option or sells a futures contract without holding the
underlying securities, currencies or futures contracts, its potential loss is
unlimited. A Fund will be required, however, to set aside with its custodian
bank liquid assets in amounts sufficient at all times to satisfy its
obligations under options and futures contracts.
 
  The successful use of options and futures will usually depend on Loomis
Sayles' ability to forecast stock market, currency or other financial market
movements correctly. A Fund's ability to hedge against adverse changes in the
 
                                      21
<PAGE>
 
value of securities held in its portfolio through options and futures also
depends on the degree of correlation between the changes in the value of
futures or options positions and changes in the values of the portfolio
securities. The successful use of futures and exchange traded options also
depends on the availability of a liquid secondary market to enable a Fund to
close its positions on a timely basis. There can be no assurance that such a
market will exist at any particular time. In the case of options that are not
traded on an exchange ("over-the-counter" options), a Fund is at risk that the
other party to the transaction will default on its obligations, or will not
permit the Fund to terminate the transaction before its scheduled maturity. As
a result of these characteristics, each Fund will treat most over-the-counter
options (and the assets it segregates to cover its obligations thereunder) as
illiquid.
   
  The options and futures markets of foreign countries are small compared to
those of the United States and consequently are characterized in most cases by
less liquidity than are the U.S. markets. In addition, foreign markets may be
subject to less detailed reporting requirements and regulatory controls than
U.S. markets. Furthermore, investments in options in foreign markets are
subject to many of the same risks as other foreign investments. See "Foreign
Securities" above.     
   
REPURCHASE AGREEMENTS     
   
  Each Fund may invest in repurchase agreements. In repurchase agreements, a
Fund buys securities from a seller, usually a bank or brokerage firm, with the
understanding that the seller will repurchase the securities at a higher price
at a later date. Such transactions afford an opportunity for a Fund to earn a
return on available cash at minimal market risk, although the Fund may be
subject to various delays and risks of loss if the seller is unable to meet
its obligations to repurchase.     
 
SECURITIES LENDING
 
  The Mid-Cap Growth, Mid-Cap Value, Small Cap Growth and Strategic Value
funds may each lend its portfolio securities to broker-dealers or other
parties under contracts calling for the deposit by the borrower with the
Fund's custodian of cash collateral equal to at least the market value of the
securities loaned, marked to market on a daily basis. The Fund will continue
to benefit from interest or dividends on the securities loaned and will also
receive interest through investment of the cash collateral in short-term
liquid investments. No loans will be made if, as a result, the aggregate
amount of such loans outstanding at any time would exceed 33 1/3% of the
Fund's total assets (taken at current value). Any voting rights, or rights to
consent, relating to securities loaned pass to the borrower. However, if a
material event affecting the investment occurs, such loans will be called so
that the securities may be voted by the Fund. The Fund pays various fees in
connection with such loans, including shipping fees and reasonable custodial
or placement fees.
 
                                      22
<PAGE>
 
  Securities loans must be fully collateralized at all times, but involve some
credit risk to the Fund if the borrower defaults on its obligation and the
Fund is delayed or prevented from recovering the collateral.
 
YEAR 2000
 
  Many computer software systems in use today cannot properly process date-
related information from and after January 1, 2000. Should any of the computer
systems employed by the Funds' major service providers fail to process this
type of information properly, that could have a negative impact on the Funds'
operations and the services that are provided to the Funds' shareholders.
Loomis Sayles and the Distributor have each advised the Funds that they are
reviewing all of their computer systems with the goal of modifying or
replacing such systems prior to January 1, 2000, to the extent necessary to
foreclose any such negative impact. In addition, Loomis Sayles has been
advised by the Funds' custodian that it is also in the process of reviewing
its systems with the same goal. As of the date of this prospectus, the Funds
and Loomis Sayles have no reason to believe that these goals will not be
achieved. Similarly, the values of certain of the portfolio securities held by
the Funds may be adversely affected by the inability of the securities'
issuers or of third parties to process this type of information properly.
 
                         THE FUNDS' INVESTMENT ADVISER
 
  The Funds' investment adviser is Loomis Sayles, One Financial Center,
Boston, Massachusetts 02111. Founded in 1926, Loomis Sayles is one of the
country's oldest and largest investment firms. The general partner of Loomis
Sayles is a special purpose corporation that is an indirect wholly-owned
subsidiary of Nvest Companies, L.P. ("Nvest Companies"). Nvest Companies'
managing general partner, Nvest Corporation, is a direct wholly-owned
subsidiary of Metropolitan Life Insurance Company ("Met Life"), a mutual life
insurance company. Nvest Companies' advising general partner, Nvest, L.P., is
a publicly traded company listed on the New York Stock Exchange. Nvest
Corporation is the sole general partner of Nvest L.P.
 
  In addition to selecting and reviewing the Funds' investments, Loomis Sayles
provides executive and other personnel for the management of the Funds. The
Trust's board of trustees supervises Loomis Sayles' conduct of the affairs of
the Funds.
       
   
  As of October 31, 1998, Charles Schwab & Co. Inc. owned 22%, 22%, 79%, 40%,
31%, 16%, 63%, and 93% of the Core Value Fund, International Equity Fund, Mid-
Cap Growth Fund, Mid-Cap Value Fund, Small Cap Growth Fund, Small Cap Value
Fund, Strategic Value Fund, and Worldwide Fund,     
 
                                      23
<PAGE>
 
   
respectively. As of October 31, 1998, Asbestos Workers Local #84 Pension Fund,
John W. George, Jr. Trust and Green Tree Financial Corp. owned 6%, 6%, and 7%
of the Core Value Fund, respectively. As of October 31, 1998, Comerica Bank
and The Security Mutual Life Insurance Company of Lincoln Nebraska owned 12%
and 7% of the International Equity Fund, respectively. As of October 31, 1998,
American National Bank owned 9% of the Mid-Cap Growth Fund. As of October 31,
1998, Carey & Co. and John W. George, Jr. Trust each owned 8% of the Mid-Cap
Value Fund. As of October 31, 1998, Carey & Co., The community Foundation
Serving Coastal South Carolina, Covie & Co, Donaldson Lufkin Jenrette
Securities Corporation, Inc., Fifth Third Bank, and Trussal and Co. owned 6%,
12%, 6%, 8%, 6%, and 6% of the Small Cap Growth Fund. As of October 31, 1998,
Smith Barney, Inc. owned 10% of the Small Cap Value Fund. As of October 31,
1998, Lazard Freres & Co. and Pomona College owned 20% and 9% of the Strategic
Value Fund, respectively. Shareholders holding more than 25% of a Fund's
shares may be deemed to control the relevant Fund.     
   
  Issac H. Green, Director of Loomis Sayles and Vice President of the Trust
and of Loomis Sayles, and James L. Carroll, Vice President of Loomis Sayles
and the Trust, have served as portfolio managers of the Core Value Fund since
October of 1997. Jeffrey W. Wardlow, Vice President of the Trust and of Loomis
Sayles, has served as a portfolio manager of the Core Value Fund since its
commencement of operations in 1991. Jerome A. Castellini, Vice President of
the Trust and of Loomis Sayles, has served as the portfolio manager of the
Mid-Cap Growth Fund since its commencement of operations in 1997. Scott S.
Pape, Vice President of the Trust and of Loomis Sayles, has served as a
portfolio manager of the Mid-Cap Growth Fund since its commencement of
operations in 1997. Dean A. Gulis, Vice President of the Trust and of Loomis
Sayles, has served as a portfolio manager of the Mid-Cap Value Fund since
October of 1997, Dawn Alston Paige and Peter Ramsden, each a Vice President of
Loomis Sayles, have served as portfolio managers of the Mid-Cap Value Fund
since October 1998. Christopher R. Ely, Vice President of the Trust and of
Loomis Sayles, has served as the portfolio manager, and Philip C. Fine and
David L. Smith, Vice Presidents of the Trust and of Loomis Sayles, have served
as assistant portfolio managers of the Small Cap Growth Fund since its
commencement of operations in 1997. Jeffrey C. Petherick, Vice President of
the Trust and of Loomis Sayles, has served as a portfolio manager of the Small
Cap Value Fund since 1993 and Mary C. Champagne, Vice President of the Trust
and of Loomis Sayles, has served as a portfolio manager of the Small Cap Value
Fund since 1995. Philip J. Schettewi, Vice President of the Trust and Loomis
Sayles, has served as the portfolio manager of the Strategic Value Fund since
its commencement of operations in 1997. Daniel J. Fuss, President of the Trust
and Executive Vice President of Loomis Sayles, has served as the portfolio
manager of the domestic bonds sector of the Worldwide Fund since     
 
                                      24
<PAGE>
 
   
that Fund's commencement of operations in 1996. E. John deBeer, Vice President
of the Trust and of Loomis Sayles, has served as portfolio manager of the
international bonds sector of the Worldwide Fund since that Fund's
commencement of operations in 1996. Quentin P. Faulkner, Vice President of the
Trust and of Loomis Sayles, has served as the portfolio manager of the
domestic equities sector of the Worldwide Fund since that Fund's commencement
of operations in 1996. Paul H. Drexler, Vice President of the Trust and of
Loomis Sayles, has served as the portfolio manager of the international
equities sector of the Worldwide Fund since that Fund's commencement of
operations in 1996 and of the International Equity Fund since 1996. Each of
the foregoing, except Messrs. Carroll, Ely, Fine, Gulis and Smith, has been
employed by Loomis Sayles for at least five years. Before joining Loomis
Sayles in 1996, Mr. Carroll was a Managing Director and Senior Energy Analyst
at PaineWebber, Inc. for more than five years. Prior to joining Loomis Sayles
in 1996, Mr. Ely was Senior Vice President and Portfolio Manager, and Messrs.
Fine and Smith were Vice Presidents and Portfolio Managers, of Keystone
Investment Management Company, Inc. Prior to joining Loomis Sayles in 1997,
Mr. Gulis was a Principal and Director of Research at Roney & Company for more
than five years.     
 
                                 FUND EXPENSES
 
  Each Fund pays Loomis Sayles a monthly investment advisory fee at the
following annual percentage rate of the Fund's average daily net assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                     RATE
   ----                                                                     ----
   <S>                                                                      <C>
   Core Value.............................................................. .50%
   International Equity.................................................... .75%
   Mid-Cap Growth.......................................................... .75%
   Mid-Cap Value........................................................... .75%
   Small Cap Growth........................................................ .75%
   Small Cap Value......................................................... .75%
   Strategic Value......................................................... .50%
   Worldwide............................................................... .75%
</TABLE>    
 
  In addition to the investment advisory fee, each Fund pays all expenses not
expressly assumed by Loomis Sayles, including taxes, brokerage commissions,
fees and expenses of registering or qualifying the Fund's shares under federal
and state securities laws, fees of the Fund's custodian, transfer agent,
independent accountants and legal counsel, expenses of shareholders' and
trustees' meetings, 12b-1 fees, expenses of preparing, printing and mailing
prospectuses to existing shareholders and fees of trustees who are not
directors, officers or employees of Loomis Sayles and its affiliated
companies.
 
                                      25
<PAGE>
 
  Under a Distribution Plan adopted pursuant to Rule 12b-1 under the
Investment Company Act of 1940, each of the Funds pays the Distributor, a
subsidiary of Loomis Sayles, a monthly distribution fee at an annual rate not
to exceed 0.25% of the Fund's average net assets attributable to the Retail
Class shares. The Distributor may pay all or any portion of the distribution
fee to securities dealers or other organizations (including, but not limited
to, any affiliate of the Distributor) as commissions, asset-based sales
charges or other compensation with respect to the sale of Retail Class shares
of the Funds, or for providing personal services to investors in Retail Class
shares of the Funds and/or the maintenance of accounts, and may retain all or
any portion of the distribution fee as compensation for the Distributor's
services as principal underwriter of the Retail Class shares of the Funds.
Loomis Sayles may pay certain broker-dealers or financial intermediaries whose
customers are shareholders of the Funds a continuing fee at an annual rate of
up to .25% of the value of Fund shares held for those customers' accounts.
These fees are paid by Loomis Sayles out of its own assets and are not
assessed against the Funds.
 
  Loomis Sayles has voluntarily agreed, for an indefinite period, to reduce
its advisory fees and/or bear other Fund expenses to the extent necessary to
limit total operating expenses of the Retail Class of shares of each Fund to
the following annual percentage rate of the Fund's average net assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                    RATE
   ----                                                                    -----
   <S>                                                                     <C>
   Core Value............................................................. 1.10%
   International Equity................................................... 1.25%
   Mid-Cap Growth......................................................... 1.25%
   Mid-Cap Value.......................................................... 1.25%
   Small Cap Growth....................................................... 1.25%
   Small Cap Value........................................................ 1.25%
   Strategic Value........................................................ 1.25%
   Worldwide.............................................................. 1.25%
</TABLE>    
 
  Loomis Sayles may change or terminate these voluntary arrangements at any
time, but the Funds' Prospectus would be supplemented to describe the change.
 
                            PORTFOLIO TRANSACTIONS
 
  Portfolio turnover considerations will not limit Loomis Sayles' investment
discretion in managing the Funds' assets. The Funds anticipate that their
portfolio turnover rates will vary significantly from time to time depending
on the volatility of economic and market conditions. High portfolio turnover
may involve higher transaction costs and higher levels of taxable gains.
 
                                      26
<PAGE>
 
                            HOW TO PURCHASE SHARES
 
  An investor may make an initial purchase of shares of any Fund by submitting
a completed application form and payment to:
 
     Boston Financial Data Services
     P.O. Box 8314
     Boston, Massachusetts 02266-8314
     Attn: Loomis Sayles Funds
 
  The minimum initial investment for the Retail Class of each Fund's shares is
$25,000 in that Fund. This minimum initial investment does not apply to
purchases through certain financial intermediaries including, but not limited
to, certain financial advisers, broker dealers, 401(k) alliances, wrap
programs, "no transaction fee" programs, bank trust departments, financial
consultants and insurance companies. The minimum investment may be waived in
whole or in part by Loomis Sayles in its sole discretion. Subsequent
investments must be at least $50.
 
  Shares of any Fund may be purchased by (i) cash, (ii) exchanging Retail
Class shares of any Fund (or any other series of Loomis Sayles Funds which
offers Retail Class shares ) provided the value of the shares exchanged meets
the investment minimum of the Fund into which the exchange is made,
(iii) exchanging securities on deposit with a custodian acceptable to Loomis
Sayles or (iv) a combination of such securities and cash. Purchase of shares
of a Fund in exchange for securities is subject in each case to the
determination by Loomis Sayles that the securities to be exchanged are
acceptable for purchase by the Fund. In all cases Loomis Sayles reserves the
right to reject any securities that are proposed for exchange. Securities
accepted by Loomis Sayles in exchange for Fund shares will be valued in the
same manner as the Fund's assets, as described below, as of the time of the
Fund's next determination of net asset value after such acceptance. All
dividends and subscription or other rights which are reflected in the market
price of accepted securities at the time of valuation become the property of
the Fund and must be delivered to the Fund upon receipt by the investor from
the issuer. A gain or loss for federal income tax purposes would be realized
upon the exchange by an investor that is subject to federal income taxation,
depending upon the investor's basis in the securities tendered. An investor
who wishes to purchase shares by exchanging securities should obtain
instructions by calling 800-633-3330, option 5 and asking for the Loomis
Sayles Funds Shareholder Services Group.
 
  Loomis Sayles will not approve the acceptance of securities in exchange for
shares of any Fund unless (1) Loomis Sayles, in its sole discretion, believes
the securities are appropriate investments for the Fund; (2) the investor
represents and agrees that all securities offered to the Fund can be resold by
the Fund without restriction under the Securities Act of 1933, as amended (the
 
                                      27
<PAGE>
 
"Securities Act") or otherwise; and (3) the securities are eligible to be
acquired under the Fund's investment policies and restrictions. No investor
owning 5% or more of a Fund's shares may purchase additional shares of that
Fund by exchange of securities.
 
  All purchases made by check should be in U.S. dollars and made payable to
State Street Bank and Trust Company ("State Street Bank"). Third party checks
will not be accepted. When purchases are made by check or periodic account
investment, redemption will not be allowed until the investment being redeemed
has been in the account for 15 calendar days.
 
  Upon acceptance of an investor's order, Boston Financial Data Services, Inc.
("BFDS"), the shareholder servicing agent for State Street Bank, opens an
account, applies the payment to the purchase of full and fractional Fund
shares and mails a statement of the account confirming the transaction.
 
  After an account has been established, an investor may send subsequent
investments at any time directly to BFDS at the above address. The remittance
must be accompanied by either the account identification slip detached from a
statement of account or a note containing sufficient information to identify
the account, i.e., the Fund name and the investor's account number or name and
social security number.
 
  Subsequent investments can also be made by federal funds wire. Investors
should instruct their banks to wire federal funds to State Street Bank and
Trust Company, ABA #011000028. The text of the wire should read as follows:
"$    amount, STATE STREET BOS ATTN Mutual Funds. Credit Fund (Fund Name and
Retail Class), DDA #9904-622-9, Account Name, Account Number." A bank may
charge a fee for transmitting funds by wire.
 
  Each Fund and the Distributor reserve the right to reject any purchase
order, including orders in connection with exchanges, for any reason which the
Fund or the Distributor in its sole discretion deems appropriate. Although the
Funds do not presently anticipate that they will do so, each Fund reserves the
right to suspend or change the terms of the offering of its shares.
 
  The price an investor pays will be the per share net asset value next
calculated after a proper investment order is received by the Trust's transfer
or other agent or subagent. Shares of each Fund are sold with no sales charge.
The net asset value of each Fund's shares is calculated once daily as of the
close of regular trading on the New York Stock Exchange on each day the
Exchange is open for trading, by dividing the Fund's net assets by the number
of shares outstanding. Portfolio securities are valued at their market value
as more fully described in the Statement of Additional Information.
 
  The Distributor may accept telephone orders from broker-dealers who have
been previously approved by the Distributor. It is the responsibility of such
 
                                      28
<PAGE>
 
broker-dealers to promptly forward purchase or redemption orders to the
Distributor. Although there is no sales charge imposed by the Fund or the
Distributor, broker-dealers may charge the investor a transaction-based fee or
other fee for their services at either the time of purchase or the time of
redemption. Such charges may vary among broker-dealers but in all cases will
be retained by the broker-dealer and not remitted to the Fund.
 
  Each Fund also offers an Institutional Class of shares that has a $1 million
minimum investment for certain categories of investors and bears lower
expenses. Because of its lower expenses, the Institutional Class of shares of
each Fund is expected to have a higher total return than the Retail Class of
shares.
 
  The Loomis Sayles Small Cap Value Fund also offers an Admin Class of shares
that is offered exclusively through intermediaries, who will be the record
owners of the shares. Because of its lower expenses, the Retail Class of
shares of the Loomis Sayles Small Cap Value Fund is expected to have a higher
total return than the Admin Class of shares.
 
                             SHAREHOLDER SERVICES
 
  The Funds offer the following shareholder services, which are more fully
described in the Statement of Additional Information. Explanations and forms
are available from BFDS. Telephone redemption and exchange privileges will be
established automatically when an investor opens an account unless an investor
elects on the application to decline the privileges. Other privileges must be
specifically elected. A signature guarantee will be required to establish a
privilege after an account is opened.
   
  FREE EXCHANGE PRIVILEGE. Retail Class shares of any Fund may be exchanged
for Retail Class shares of any other Fund (or any other fund that is a series
of Loomis Sayles Funds and that offers Retail Class shares) or for shares of
certain money market funds advised by New England Funds Management, L.P., an
affiliate of Loomis Sayles, provided the value of the shares exchanged meets
the investment minimum of that Fund and, in the case of the Loomis Sayles High
Yield Fund, Loomis Sayles has approved the exchange of shares. Exchanges may
be made by written instructions or by telephone, unless an investor elected on
the application to decline telephone exchange privileges. The exchange
privilege should not be viewed as a means for taking advantage of short-term
swings in the market, and the Funds reserve the right to terminate or limit
the privilege of any shareholder who makes more than four exchanges in any
calendar year. The Funds may terminate or change the terms of the exchange
privilege at any time, upon 60 days' notice to shareholders. An exchange is a
taxable event for federal income tax purposes in which a gain or loss would be
realized by an investor that is subject to federal income taxation.     
 
                                      29
<PAGE>
 
  RETIREMENT PLANS. The Funds' shares may be purchased by all types of tax-
deferred retirement plans. Loomis Sayles makes available retirement plan forms
for IRAs.
 
  SYSTEMATIC WITHDRAWAL PLANS. If the value of an account is at least $25,000,
an investor may have periodic cash withdrawals automatically paid to the
investor or any person designated by the investor.
 
  AUTOMATIC INVESTMENT PLAN. Voluntary monthly investments of at least $50 may
be made automatically by pre-authorized withdrawals from an investor's
checking account.
 
                             HOW TO REDEEM SHARES
 
  An investor can redeem shares by sending a written request to Boston
Financial Data Services, Inc., P.O. Box 8314, Boston, Massachusetts 02266. As
described below, an investor may also redeem shares by calling BFDS at 800-
626-9390. Proceeds resulting from a written or telephone redemption request
can be wired to an investor's bank account or sent by check in the name of the
registered owners to their record address.
 
  The written request must include the name of the Fund, the account number,
the exact name(s) in which the shares are registered, and the number of shares
or the dollar amount to be redeemed. All owners of the shares must sign the
request in the exact names in which the shares are registered (this appears on
an investor's confirmation statement) and should indicate any special capacity
in which they are signing (such as trustee or custodian or on behalf of a
partnership, corporation or other entity). Investors requesting that
redemption proceeds be wired to their bank accounts must provide specific wire
instructions.
 
  If (1) an investor is redeeming shares worth more than $50,000, (2) an
investor is requesting that the proceeds check be made out to someone other
than the registered owners or be sent to an address other than the record
address, (3) the account registration has changed within the last 30 days or
(4) an investor is instructing us to wire the proceeds to a bank account not
designated on the application, the investor must have his or her signature
guaranteed by an eligible guarantor. This requirement may be waived by Loomis
Sayles in its sole discretion. Eligible guarantors include commercial banks,
trust companies, savings associations, credit unions and brokerage firms that
are members of domestic securities exchanges. Before submitting the redemption
request, the investor should verify with the guarantor institution that it is
an eligible guarantor. Signature guarantees by notaries public are not
acceptable.
 
  When an investor telephones a redemption request, the proceeds are wired to
the bank account previously chosen by the investor. A wire fee (currently $5)
 
                                      30
<PAGE>
 
will be deducted from the proceeds. A telephonic redemption request must be
received by BFDS prior to the close of regular trading on the New York Stock
Exchange. If an investor telephones a request to BFDS after the Exchange
closes or on a day when the Exchange is not open for business, BFDS cannot
accept the request and a new one will be necessary.
 
  If an investor decides to change the bank account to which proceeds are to
be wired, the investor must send in this change in writing with a signature
guarantee. Telephonic redemptions may only be made if the investor's bank is a
member of the Federal Reserve System or has a correspondent bank that is a
member of the System. Unless the investor indicates otherwise on the account
application, BFDS will be authorized to act upon redemption and exchange
instructions received by telephone from the investor or any person claiming to
act as the investor's representative who can provide BFDS with the investor's
account registration and address as it appears on the records of State Street
Bank. BFDS will employ these or other reasonable procedures to confirm that
instructions communicated by telephone are genuine; the Fund, State Street
Bank, BFDS, the Distributor and Loomis Sayles will not be liable for any
losses due to unauthorized or fraudulent instructions if these or other
reasonable procedures are followed. For information, consult BFDS. In times of
heavy market activity, an investor who encounters difficulty in placing a
redemption or exchange order by telephone may wish to place the order by mail
as described above.
 
  The redemption price will be the net asset value per share next determined
after the redemption request and any necessary special documentation are
received by BFDS in proper form.
 
  Proceeds resulting from a written redemption request will normally be mailed
to an investor within seven days after receipt of the investor's request in
good order. Telephonic redemption proceeds will normally be wired to an
investor's bank on the first business day following receipt of a proper
redemption request. If an investor purchased shares by check and the check was
deposited less than fifteen days prior to the redemption request, the Fund may
withhold redemption proceeds until the check has cleared.
 
  The Fund may suspend the right of redemption and may postpone payment for
more than seven days when the New York Stock Exchange is closed for other than
weekends or holidays, or if permitted by the rules of the SEC when trading on
the Exchange is restricted or during an emergency which makes it impracticable
for the Fund to dispose of its securities or to determine fairly the value of
its net assets, or during any other period permitted by the SEC for the
protection of investors.
 
                                      31
<PAGE>
 
                    CALCULATION OF PERFORMANCE INFORMATION
 
  "Total return" for the one-, five- and ten-year periods (or for the life of
the class, if shorter) through the most recent calendar quarter represents the
average annual compounded rate of return on an investment of $1,000 in a Fund.
Total return may also be presented for other periods.
 
                DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES
 
  The Funds declare and pay their net investment income to shareholders as
dividends annually. Each Fund also distributes all of its net capital gains
realized from the sale of portfolio securities. Any capital gain distributions
are normally made annually, but may, to the extent permitted by law, be made
more frequently as deemed advisable by the trustees of the Trust. The Trust's
trustees may change the frequency with which the Funds declare or pay
dividends.
   
  Dividends and capital gain distributions will automatically be reinvested in
additional shares of the same Fund unless an investor has elected to receive
cash. Each Fund intends to qualify as a regulated investment company under the
Internal Revenue Code of 1986, as amended. As such, so long as a Fund
distributes substantially all its net investment income and net capital gains
to its shareholders, the Fund itself does not pay any federal income tax to
the extent such income and gains are so distributed.     
   
  An investor's income dividends and short-term capital gain distributions
(that is, net gains from securities held for not more than a year) are taxable
as ordinary income whether distributed in cash or additional shares.
Distributions designated by all Funds as deriving from net gains on securities
held for more than one year will be taxable as such (generally at a 20% rate
for noncorporate shareholders) whether distributed in cash or additional
shares and regardless of how long an investor has owned shares of the Fund.     
   
  A dividend or distribution made shortly after the purchase of shares of a
Fund by a shareholder, although in effect a return of capital to that
particular shareholder, would be taxable to him or her as described above. If
a shareholder held shares six months or less and during that period received a
distribution of net capital gains, any loss realized on the sale of such
shares during such six-month period would be a long-term capital loss to the
extent of such distribution.     
 
  Each Fund is required to withhold 31% of any redemption proceeds (including
the value of shares exchanged) and all income dividends and capital gain
distributions it pays to an investor (1) if an investor does not provide a
correct, certified taxpayer identification number, (2) if the Fund is notified
that an investor has underreported income in the past, or (3) if an investor
fails to certify to the Fund that the investor is not subject to such
withholding.
 
                                      32
<PAGE>
 
   
  Certain designated dividends from the Funds are expected to be eligible for
the dividends-received deduction for corporate shareholders that meet a
holding period requirement.     
 
  State Street Bank will send each investor and the IRS an annual statement
detailing federal tax information, including information about dividends and
distributions paid to the investor during the preceding year. Be sure to keep
this statement as a permanent record. A fee may be charged for any duplicate
information that an investor requests.
 
NOTE:   The foregoing summarizes certain tax consequences of investing in the
        Funds. Before investing, an investor should consult his or her own tax
        adviser for more information concerning the federal, foreign, state
        and local tax consequences of investing in, redeeming or exchanging
        Fund shares.
 
                                      33
<PAGE>
 
 
INVESTMENT ADVISER
Loomis, Sayles & Company, L.P.
One Financial Center
Boston, Massachusetts 02111
 
DISTRIBUTOR
Loomis Sayles Distributors, L.P.
One Financial Center
Boston, Massachusetts 02111
 
TRANSFER AND DIVIDEND PAYING AGENT
AND CUSTODIAN OF ASSETS
State Street Bank and Trust Company
Boston, Massachusetts 02102
 
SHAREHOLDER SERVICING AGENT FOR
STATE STREET BANK AND TRUST COMPANY
Boston Financial Data Services, Inc.
P.O. Box 8314
Boston, Massachusetts 02266
 
LEGAL COUNSEL
Ropes & Gray
One International Place
Boston, Massachusetts 02110
 
INDEPENDENT ACCOUNTANTS
   
PricewaterhouseCoopers LLP     
One Post Office Square
Boston, Massachusetts 02109
 
<PAGE>

[LOGO OF LOOMIS SAYLES FUNDS APPEARS HERE]
 
 ONE FINANCIAL CENTER . BOSTON, MASSACHUSETTS 02111 . (800) 633-3330
 
THE LOOMIS SAYLES FUNDS--FIXED INCOME FUNDS
 
 INSTITUTIONAL CLASS SHARES OF:
 
  LOOMIS SAYLES BOND FUND
  LOOMIS SAYLES GLOBAL BOND FUND
         
  LOOMIS SAYLES INTERMEDIATE MATURITY BOND FUND
  LOOMIS SAYLES INVESTMENT GRADE BOND FUND
  LOOMIS SAYLES MUNICIPAL BOND FUND
        
  LOOMIS SAYLES SHORT-TERM BOND FUND
<PAGE>
 
PROSPECTUS                                                    
                                                           JANUARY 1, 1999     
 
THE LOOMIS SAYLES FUNDS--FIXED INCOME FUNDS
   
  Loomis Sayles Bond Fund, Loomis Sayles Global Bond Fund, Loomis Sayles
Intermediate Maturity Bond Fund, Loomis Sayles Investment Grade Bond Fund,
Loomis Sayles Municipal Bond Fund and Loomis Sayles Short-Term Bond Fund (the
"Funds" and each a "Fund"), each a series of Loomis Sayles Funds, are
separately managed, no-load mutual funds, each of which has its own investment
objective and policies. Loomis, Sayles & Company, L.P. ("Loomis Sayles") is
the investment adviser of each Fund.     
   
  The Funds (other than Loomis Sayles Municipal Bond Fund) offer two classes
of shares: an Institutional Class that is described in this Prospectus and a
Retail Class, which generally has a lower minimum investment and bears higher
expenses, that is described in a separate prospectus. The Loomis Sayles Bond
Fund also offers a third class of shares: an Admin Class, bearing higher
expenses than the Institutional or Retail Class, that is described in a
separate prospectus. This Prospectus concisely describes the information that
an investor should know before investing in the Institutional Class shares of
any Fund. Please read it carefully and keep it for future reference. A
Statement of Additional Information (SAI) dated January 1, 1999, as revised
from time to time, is available free of charge; write to Loomis Sayles
Distributors, L.P. (the "Distributor"), One Financial Center, Boston,
Massachusetts 02111 or telephone 800-633-3330. The SAI, which contains more
detailed information about the Funds, has been filed with the Securities and
Exchange Commission (the "SEC") and is available along with other related
materials on the SEC's Internet Web site (http://www.sec.gov). The SAI is
incorporated herein by reference (legally forms a part of the Prospectus). To
obtain more information about the Retail Class or Admin Class of shares,
please call the Distributor toll-free at 800-633-3330, contact your financial
intermediary, or visit our Internet Website (http://www.loomissayles.com).
    
  For information about:                    For all other information about
   .Establishing an account                 the Funds:
   .Account procedures and status           CALL 800-633-3330
   .Exchanges
   .Shareholder services
  CALL 800-626-9390
 
  THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS
A CRIMINAL OFFENSE.
       
                                       1
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>   
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
SUMMARY OF EXPENSES.......................................................   3
FINANCIAL HIGHLIGHTS......................................................   5
THE TRUST.................................................................  11
INVESTMENT OBJECTIVES AND POLICIES........................................  11
MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS AND RISK CONSIDERATIONS.....  16
THE FUNDS' INVESTMENT ADVISER.............................................  27
FUND EXPENSES.............................................................  28
PORTFOLIO TRANSACTIONS....................................................  29
HOW TO PURCHASE SHARES....................................................  29
SHAREHOLDER SERVICES......................................................  32
HOW TO REDEEM SHARES......................................................  33
CALCULATION OF PERFORMANCE INFORMATION....................................  34
DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES...........................  35
APPENDIX A
  DESCRIPTION OF BOND RATINGS.............................................  38
</TABLE>    
 
                                       2
<PAGE>
 
                              SUMMARY OF EXPENSES
           (FOR AN INSTITUTIONAL CLASS SHARE OF EACH INDICATED FUND)
   
  The following information is provided as an aid in understanding the various
expenses that an investor in a Fund will bear indirectly. The information
below is based on expenses for the Funds' most recent fiscal year, and should
not be considered a representation of past or future expenses, as actual
expenses may be greater or less than those shown. Also, the 5% annual return
assumed in the Example should not be considered a representation of investment
performance, as actual performance will vary.     
 
<TABLE>   
<CAPTION>
                                               INTERMEDIATE INVESTMENT
                                     GLOBAL      MATURITY     GRADE     MUNICIPAL
                            BOND      BOND         BOND        BOND       BOND
                            FUND      FUND         FUND        FUND       FUND
                            ----     ------    ------------ ----------  ---------
 <S>                        <C>      <C>       <C>          <C>         <C>
 Shareholder Transaction
  Expenses:
 Maximum Sales Load
  Imposed on Purchases
  (as % of offering
  price).................   none      none         none        none       none
 Maximum Sales Load
  Imposed on Reinvested
  Dividends (as % of
  offering price)........   none      none         none        none       none
 Maximum Deferred Sales
  Load (as % of original
  purchase price or
  redemption proceeds)...   none      none         none        none       none
 Redemption Fees/1..../..   none      none         none        none       none
 Exchange Fees...........   none      none         none        none       none
 Annual Fund Operating
  Expenses (as a
  percentage of average
  net assets):
 Management Fees.........    .60%      .60%         .40%        .40%       .40%
 12b-1 Fees..............   none      none         none        none       none
 Other Operating Expenses
  (after expense
  reimbursements where
  indicated).............    .15%/2/   .30%/2/      .15%/2/     .15%/2/    .20%/2/
 Total Fund Operating
  Expenses (after expense
  reimbursements where
  indicated).............    .75%/2/   .90%/2/      .55%/2/     .55%/2/    .60%/2/
 Example:
 An investor would pay
  the following expenses
  on a $1,000 investment
  assuming a 5% annual
  return (with or without
  a redemption at the end
  of each time period):
 One Year................    $ 8      $  9          $ 6         $ 6        $ 6
 Three Years.............    $24      $ 29          $18         $18        $19
 Five Years..............    $42      $ 50          $31         $31        $33
 Ten Years...............    $93      $111          $69         $69        $75
</TABLE>    
 
                                       3
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                   SHORT-TERM
                                                                      BOND
                                                                      FUND
                                                                   ----------
<S>                                                                <C>
Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on Purchases (as % of offering
  price)..........................................................    none
 Maximum Sales Load Imposed on Reinvested Dividends (as % of
  offering price).................................................    none
 Maximum Deferred Sales Load (as % of original purchase price or
  redemption proceeds)............................................    none
 12b-1 Fees.......................................................    none
 Redemption Fees/1............................................./..    none
 Exchange Fees....................................................    none
Annual Fund Operating Expenses (as a percentage of average net
 assets):
 Management Fees..................................................     .25%
 Other Operating Expenses (after expense reimbursements where
  indicated)......................................................     .25%/2/
 Total Fund Operating Expenses (after expense reimbursements where
  indicated)......................................................     .50%/2/
Example:
An investor would pay the following expenses on a $1,000
 investment assuming a 5% annual return (with or without a
 redemption at the end of each time period):
 One Year.........................................................     $ 5
 Three Years......................................................     $16
 Five Years.......................................................     $28
 Ten Years........................................................     $63
</TABLE>    
- -----------
/1/A $5 charge applies to any wire transfer of redemption proceeds from any
   Fund.
          
/2/Loomis Sayles has voluntarily agreed, for an indefinite period, to limit
   the Funds' Total Operating Expenses to the percentages of net assets shown in
   the table. Without this agreement, Other Operating Expenses and Total
   Operating Expenses would have been 0.16% and 0.76%, respectively, for the
   Bond Fund, 0.58% and 1.18%, respectively, for the Global Bond Fund, 1.87% and
   2.27%, respectively, for the Intermediate Maturity Bond Fund and 3.79% and
   4.19%, respectively, for the Investment Grade Bond Fund, 1.30% and 1.70%,
   respectively, for the Municipal Bond Fund, 0.58% and 0.83%, respectively, for
   the Short-Term Bond Fund.     
                                          4
<PAGE>
 
                             FINANCIAL HIGHLIGHTS
           (FOR AN INSTITUTIONAL CLASS SHARE OF EACH INDICATED FUND
                 OUTSTANDING THROUGHOUT THE INDICATED PERIODS)
   
  The financial highlights tables that follow have been audited by
PricewaterhouseCoopers LLP, independent accountants. The following information
should be read in conjunction with the financial highlights, financial
statements and the notes thereto contained in the Funds' 1998 Annual Report,
which is incorporated by reference in this Prospectus and the Statement of
Additional Information.     
 
<TABLE>   
<CAPTION>
                                                                    BOND FUND                                          
                                          -------------------------------------------------------------------          
                             NINE                                                                                      
                            MONTHS                                                                   MAY 16**          
                            ENDED                         YEAR ENDED DEC. 31,                           TO             
                          SEPT. 30*       ---------------------------------------------------------  DEC. 31,          
                             1998            1997       1996      1995     1994     1993     1992      1991            
                          ----------      ----------  --------  --------  -------  -------  -------  --------          
<S>                       <C>             <C>         <C>       <C>       <C>      <C>      <C>      <C>               
Net asset value,                                                                                                       
 beginning of period....  $    12.83      $    12.38  $  12.29  $  10.05  $ 11.37  $ 10.36  $ 10.23   $10.00           
                          ----------      ----------  --------  --------  -------  -------  -------   ------           
Income from investment                                                                                                 
 operations--                                                                                                          
 Net investment income                                                                                                 
  (loss)................        0.69            0.86      0.86      0.82     0.83     0.84     0.76     0.52           
 Net realized and                                                                                                      
  unrealized gain (loss)                                                                                               
  on investments........       (0.78)           0.67      0.35      2.32    (1.29)    1.43     0.67     0.36           
                          ----------      ----------  --------  --------  -------  -------  -------   ------           
 Total from investment                                                                                                 
  operations............       (0.09)           1.53      1.21      3.14    (0.46)    2.27     1.43     0.88           
                          ----------      ----------  --------  --------  -------  -------  -------   ------           
Less distributions--                                                                                                   
 Dividends from net                                                                                                    
  investment income.....       (0.44)          (0.86)    (0.86)    (0.82)   (0.84)   (0.81)   (0.76)   (0.52)          
 Distributions in excess                                                                                               
  of net investment                                                                                                    
  income................        0.00            0.00      0.00      0.00    (0.02)    0.00     0.00     0.00           
 Distributions from net                                                                                                
  realized capital                                                                                                     
  gains.................        0.00           (0.22)    (0.26)    (0.08)    0.00    (0.45)   (0.54)   (0.13)          
                          ----------      ----------  --------  --------  -------  -------  -------   ------           
 Total distributions....       (0.44)          (1.08)    (1.12)    (0.90)   (0.86)   (1.26)   (1.30)   (0.65)          
                          ----------      ----------  --------  --------  -------  -------  -------   ------           
Net asset value, end of                                                                                                
 period.................  $    12.30      $    12.83  $  12.38  $  12.29  $ 10.05  $ 11.37  $ 10.36   $10.23           
                          ==========      ==========  ========  ========  =======  =======  =======   ======           
Total return (%)***.....        (0.9)++         12.7      10.3      32.0     (4.1)    22.2     14.3      8.9           
Net assets, end of                                                                                                     
 period (000)...........  $1,455,312      $1,261,910  $541,244  $255,710  $82,985  $64,222  $18,472   $9,922           
Ratio of operating                                                                                                     
 expenses to average net                                                                                               
 assets (%)****.........        0.75+           0.75      0.75      0.79     0.84     0.94     1.00     1.00+          
Ratio of net investment                                                                                                
 income to average net                                                                                                 
 assets (%).............        7.34+           7.36      7.93      8.34     7.92     8.26     7.50     8.97+          
Portfolio turnover rate                                                                                                
 (%)....................          24++            41        42        35       87      170      101      126           
Without giving effect to                                                                                               
 voluntary expense                                                                                                     
 limitations:                                                                                                          
 The ratio of operating                                                                                                
  expenses to average                                                                                                  
  net assets would have                                                                                                
  been (%)..............        0.76+           0.77      0.75      0.79     0.84     0.94     1.55     1.78+          
 Net investment income                                                                                                 
  per share would have                                                                                                 
  been..................  $     0.69      $     0.85  $   0.86  $   0.82  $  0.83  $  0.84  $  0.70   $ 0.47            
</TABLE>    
- -----------
   
   * The fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
   + Computed on an annualized basis.     
    
  ++ Periods less than one year are not annualized.      
 
                                       5
<PAGE>
 
<TABLE>   
<CAPTION>
                                                    GLOBAL BOND FUND
                          ---------------------------------------------------------------------------
                              NINE
                             MONTHS                                                          MAY 10**
                              ENDED                  YEAR ENDED DEC. 31,                        TO
                          SEPTEMBER 30* ---------------------------------------------------  DEC. 31,
                              1998       1997     1996     1995     1994     1993     1992     1991
                          ------------- -------  -------  -------  -------  -------  ------  --------
<S>                       <C>           <C>      <C>      <C>      <C>      <C>      <C>     <C>
Net asset value,
 beginning of period....     $ 11.83    $ 12.35  $ 11.39  $  9.82  $ 11.06  $ 10.32  $11.38   $10.00
                             -------    -------  -------  -------  -------  -------  ------   ------
Income from investment
 operations--
 Net investment income
  (loss)................        0.53       0.71     0.44     1.04     0.67     0.54    0.70     0.37
 Net realized and
  unrealized gain (loss)
  on investments........       (0.43)     (0.42)    1.27     1.31    (1.63)    0.96   (0.60)    1.31
                             -------    -------  -------  -------  -------  -------  ------   ------
 Total from investment
  operations............        0.10       0.29     1.71     2.35    (0.96)    1.50    0.10     1.68
                             -------    -------  -------  -------  -------  -------  ------   ------
Less distributions--
 Dividends from net
  investment income.....        0.00      (0.69)   (0.75)   (0.78)   (0.04)   (0.49)  (0.77)   (0.30)
 Distributions in excess
  of net investment
  income................        0.00      (0.12)    0.00     0.00     0.00     0.00    0.00     0.00
 Distributions from net
  realized capital
  gains.................        0.00       0.00     0.00     0.00     0.00    (0.27)  (0.39)    0.00
 Distributions from
  capital...............        0.00       0.00     0.00     0.00    (0.24)    0.00    0.00     0.00
                             -------    -------  -------  -------  -------  -------  ------   ------
 Total distributions....        0.00      (0.81)   (0.75)   (0.78)   (0.28)   (0.76)  (1.16)   (0.30)
                             -------    -------  -------  -------  -------  -------  ------   ------
Net asset value, end of
 period.................     $ 11.93    $ 11.83  $ 12.35  $ 11.39  $  9.82  $ 11.06  $10.32   $11.38
                             =======    =======  =======  =======  =======  =======  ======   ======
Total return (%)***.....         0.9++      2.3     15.0     23.9     (8.7)    14.6     0.8     16.9
Net assets, end of
 period (000)...........     $29,860    $28,401  $26,513  $10,304  $25,584  $21,378  $9,968   $4,308
Ratio of operating
 expenses to average net
 assets (%)****.........        0.90+      0.90     1.50     1.50     1.30     1.50    1.50     1.50+
Ratio of net investment
 income to average net
 assets (%).............        6.00+      5.88     6.37     8.17     7.02     5.54    6.99     6.81+
Portfolio turnover rate
 (%)....................          28++       75      131      148      153      150      72      137
Without giving effect to
 voluntary expense
 limitations:
 The ratio of operating
  expenses to average
  net assets would have
  been (%)..............        1.18+      1.22     1.77     1.69     1.30     1.51    2.58     3.99+
 Net investment income
  per share would have
  been..................     $  0.51    $  0.67  $  0.42  $  1.02  $  0.67  $  0.54  $ 0.59   $ 0.23
</TABLE>    
- ----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
   + Computed on an annualized basis.     
    
  ++ Periods less than one year are not annualized.       

                                       6
<PAGE>
 
<TABLE>   
<CAPTION>
                                       INTERMEDIATE MATURITY BOND FUND
                                       --------------------------------------
                                              NINE              JAN. 2**
                                             MONTHS                TO
                                             ENDED              DEC. 31,
                                       SEPTEMBER 30* 1998         1997
                                       ------------------     ---------------
<S>                                    <C>                    <C>
Net asset value, beginning of
 period..............................     $         10.03      $         10.00
                                          ---------------      ---------------
Income from investment operations--
 Net investment income (loss)........                0.51***              0.64***
 Net realized and unrealized gain
  (loss) on investments..............               (0.16)                0.00
                                          ---------------      ---------------
 Total from investment operations....                0.35                 0.64
                                          ---------------      ---------------
Less distributions--
 Dividends from net investment
  income.............................               (0.32)               (0.56)
 Distributions in excess of net
  investment income..................                0.00                (0.03)
 Distributions from net realized
  capital gains......................                0.00                (0.02)
                                          ---------------      ---------------
 Total distributions.................               (0.32)               (0.61)
                                          ---------------      ---------------
Net asset value, end of period.......          $    10.06      $         10.03
                                          ===============      ===============
Total return (%)****.................                 3.5+++               6.4
Net assets, end of period (000)......     $         8,601      $         6,305
Ratio of operating expenses to
 average net assets (%)+.............                0.55++               0.55 ++
Ratio of net investment income to
 average net assets (%)..............                6.71++               6.38 ++
Portfolio turnover rate (%)..........                  32+++               119
Without giving effect to voluntary
 expense limitations:
 The ratio of operating expenses to
  average net assets would have been
  (%)................................                2.27++               3.66 ++
 Net investment income per share
  would have been....................     $          0.38***   $          0.29***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
          
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
   + The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
  ++ Computed on an annualized basis.     
    
 +++ Periods less than one year are not annualized.      

                                       7
<PAGE>
 
<TABLE>   
<CAPTION>
                                                          INVESTMENT GRADE BOND
                                                                   FUND
                                                          ----------------------
                                                           NINE MONTHS  JAN. 2**
                                                              ENDED        TO
                                                          SEPTEMBER 30* DEC. 31,
                                                              1998        1997
                                                          ------------- --------
<S>                                                       <C>           <C>
Net asset value, beginning of period....................     $10.59      $10.00
                                                             ------      ------
Income from investment operations--
 Net investment income (loss)...........................       0.52        0.65
 Net realized and unrealized gain (loss) on
  investments...........................................      (0.50)       0.77
                                                             ------      ------
 Total from investment operations.......................       0.02        1.42
                                                             ------      ------
Less distributions--
 Dividends from net investment income...................      (0.33)      (0.63)
 Distributions in excess of net investment income.......       0.00       (0.08)
 Distributions from net realized capital gains..........       0.00       (0.12)
                                                             ------      ------
 Total distributions....................................      (0.33)      (0.83)
                                                             ------      ------
Net asset value, end of period..........................     $10.28      $10.59
                                                             ======      ======
Total return (%)***.....................................        0.0++      14.5
Net assets, end of period (000).........................     $2,778      $2,445
Ratio of operating expenses to average net assets
 (%)****................................................       0.55+       0.55+
Ratio of net investment income to average net assets
 (%)....................................................       6.68+       6.74+
Portfolio turnover rate (%).............................         48++       112
Without giving effect to voluntary expense limitations:
 The ratio of operating expenses to average net assets
  would have been (%)...................................       4.19+       7.59+
 Net investment income per share would have been........     $ 0.24      $(0.03)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
   + Computed on an annualized basis.     
    
  ++ Periods less than one year are not annualized.      
       

                                       8
<PAGE>
 
<TABLE>   
<CAPTION>
                                              MUNICIPAL BOND FUND
                          ---------------------------------------------------------------------
                            NINE                                                                      
                           MONTHS                                                      MAY 29**       
                            ENDED                 YEAR ENDED DEC. 31,                     TO          
                          SEPT. 30*    ----------------------------------------------  DEC. 31,       
                            1998        1997    1996    1995    1994    1993    1992     1991         
                          ---------    ------  ------  ------  ------  ------  ------  --------       
<S>                       <C>          <C>     <C>     <C>     <C>     <C>     <C>     <C>            
Net asset value,                                                                                      
 beginning of period....   $ 11.70     $11.29  $11.53  $10.41  $11.54  $10.95  $10.55   $10.00        
                           -------     ------  ------  ------  ------  ------  ------   ------        
Income from investment                                                                                
 operations--                                                                                         
 Net investment income                                                                                
  (loss)................      0.40       0.56    0.52    0.52    0.52    0.51    0.51     0.24        
 Net realized and                                                                                     
  unrealized gain (loss)                                                                              
  on investments........      0.27       0.51   (0.15)   1.16   (1.13)   0.74    0.46     0.56        
                           -------     ------  ------  ------  ------  ------  ------   ------        
 Total from investment                                                                                
  operations............      0.67       1.07    0.37    1.68   (0.61)   1.25    0.97     0.80        
                           -------     ------  ------  ------  ------  ------  ------   ------        
Less distributions--                                                                                  
 Dividends from net                                                                                   
  investment income.....     (0.40)     (0.56)  (0.52)  (0.52)  (0.52)  (0.51)  (0.51)   (0.23)       
 Distributions from net                                                                               
  realized capital                                                                                    
  gains.................     (0.01)     (0.10)  (0.09)  (0.04)   0.00   (0.15)  (0.06)   (0.02)       
                           -------     ------  ------  ------  ------  ------  ------   ------        
 Total distributions....     (0.41)     (0.66)  (0.61)  (0.56)  (0.52)  (0.66)  (0.57)   (0.25)       
                           -------     ------  ------  ------  ------  ------  ------   ------        
Net asset value, end of                                                                               
 period.................   $ 11.96     $11.70  $11.29  $11.53  $10.41  $11.54  $10.95   $10.55        
                           =======     ======  ======  ======  ======  ======  ======   ======        
Total return (%)***.....       5.9++      9.8     3.3    16.5    (5.4)   11.6     9.4      8.1        
Net assets, end of                                                                                    
 period (000)...........   $10,056     $8,752  $8,701  $7,961  $7,270  $5,160  $2,200   $  706        
Ratio of operating                                                                                    
 expenses to average net                                                                              
 assets (%)****.........      0.60+      0.60    1.00    1.00    1.00    1.00    1.00     1.00+       
Ratio of net investment                                                                               
 income to average net                                                                                
 assets (%).............      4.62+      4.90    4.61    4.72    4.79    4.50    4.81     5.03+       
Portfolio turnover rate                                                                               
 (%)....................        30++       50      38      41      28      36      32       26        
Without giving effect to                                                                              
 voluntary expense                                                                                    
 limitations:                                                                                         
 The ratio of operating                                                                               
  expenses to average                                                                                 
  net assets would have                                                                               
  been (%)..............      1.70+      1.80    2.31    2.02    2.37    3.22    7.65    21.58+       
 Net investment income                                                                                
  per share would have                                                                                
  been..................   $  0.31     $ 0.42  $ 0.37  $ 0.41  $ 0.37  $ 0.26  $(0.19)  $(0.74)        
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
   + Computed on an annualized basis.     
    
   ++ Periods less than one year are not annualized.       
       

                                       9
<PAGE>
 
<TABLE>   
<CAPTION>
                                             SHORT-TERM BOND FUND
                          ------------------------------------------------------------------
                            NINE                                                               
                           MONTHS                                                   AUG. 3**   
                            ENDED            YEAR ENDED DEC. 31,                       TO      
                          SEPT. 30*    ----------------------------------           DEC. 31    
                            1998        1997     1996     1995     1994     1993      1992     
                          ---------    -------  -------  -------  -------  -------  --------   
<S>                       <C>          <C>      <C>      <C>      <C>      <C>      <C>        
Net asset value,                                                                               
 beginning of period....   $  9.75     $  9.70  $  9.81  $  9.46  $  9.95  $  9.87   $10.00    
                           -------     -------  -------  -------  -------  -------   ------    
Income from investment                                                                         
 operations--                                                                                  
 Net investment income..      0.44        0.61     0.55     0.63     0.66     0.59     0.22    
 Net realized and                                                                              
  unrealized gain (loss)                                                                       
  on investments........      0.21        0.06    (0.11)    0.35    (0.49)    0.08    (0.13)   
                           -------     -------  -------  -------  -------  -------   ------    
 Total from investment                                                                         
  operations............      0.65        0.67     0.44     0.98     0.17     0.67     0.09    
                           -------     -------  -------  -------  -------  -------   ------    
Less distributions--                                                                           
 Dividends from net                                                                            
  investment income.....     (0.44)      (0.62)   (0.55)   (0.63)   (0.66)   (0.59)   (0.22)   
                           -------     -------  -------  -------  -------  -------   ------    
 Total distributions....     (0.44)      (0.62)   (0.55)   (0.63)   (0.66)   (0.59)   (0.22)   
                           -------     -------  -------  -------  -------  -------   ------    
Net asset value, end of                                                                        
 period.................   $  9.96     $  9.75  $  9.70  $  9.81  $  9.46  $  9.95   $ 9.87    
                           =======     =======  =======  =======  =======  =======   ======    
Total return (%)***.....       6.8++       7.1      4.7     10.6      1.8      7.0      0.9    
Net assets, end of                                                                             
 period (000)...........   $27,288     $18,792  $18,229  $26,039  $19,440  $15,226   $5,121    
Ratio of operating                                                                             
 expenses to average net                                                                       
 assets (%)****.........      0.50+       0.50     1.00     1.00     1.00     1.00     1.00+   
Ratio of net investment                                                                        
 income to average net                                                                         
 assets (%).............      5.94+       6.34     5.69     6.46     6.88     5.97     5.49+   
Portfolio turnover rate                                                                        
 (%)....................        47++        91      120      214       34       81       31    
Without giving effect to                                                                       
 voluntary expense                                                                             
 limitations:                                                                                  
 The ratio of operating                                                                        
  expenses to average                                                                          
  net assets would have                                                                        
  been (%)..............      0.83+       1.19     1.17     1.03     1.33     1.55     3.74+   
 Net investment income                                                                         
  per share would have                                                                         
  been..................   $  0.41     $  0.55  $  0.53  $  0.62  $  0.63  $  0.54   $ 0.11     
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne  other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
   + Computed on an annualized basis.     
    
   ++ Periods less than one year are not annualized.       
   
NOTE: Further information about each Fund's performance is contained in the
    Funds' annual report to shareholders, which may be obtained without
    charge.     
 
                                      10
<PAGE>
 
                                   THE TRUST
 
  Each Fund is a series of Loomis Sayles Funds (the "Trust"). The Trust is a
diversified open-end management investment company organized as a
Massachusetts business trust on February 20, 1991. The Trust is authorized to
issue an unlimited number of full and fractional shares of beneficial interest
in multiple series. Shares are freely transferable and entitle shareholders to
receive dividends as determined by the Trust's board of trustees and to cast a
vote for each share held at shareholder meetings. The Trust does not generally
hold shareholder meetings and will do so only when required by law.
Shareholders may call meetings to consider removal of the Trust's trustees.
 
                      INVESTMENT OBJECTIVES AND POLICIES
 
LOOMIS SAYLES BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
   
  The Fund seeks to achieve its objective by normally investing substantially
all of its assets in fixed income securities, although up to 20% of its total
assets may be invested in preferred stocks. At least 65% of the Fund's total
assets will normally be invested in bonds. The fixed income securities in
which the Fund may invest include corporate securities, securities issued or
guaranteed by the U.S. Government or its authorities or instrumentalities
("U.S. Government Securities"), commercial paper, zero coupon securities,
mortgage-backed securities, stripped mortgage-backed securities,
collateralized mortgage obligations ("CMOs"), asset-backed securities, when-
issued securities, real estate investment trusts ("REITs"), Rule 144A
securities, repurchase agreements and convertible securities. The Fund may
engage in options and futures transactions, repurchase transactions, foreign
currency hedging transactions and swap transactions.     
   
  The Fund may invest any portion of its assets in securities of Canadian
issuers, and up to 20% of its total assets in securities of other foreign
issuers. The Fund may also invest up to 35% of its total assets in securities
of below investment grade quality (commonly known as "junk bonds"). Securities
of below investment grade quality are securities rated below the top four
rating categories by each major rating agency that has rated the security,
including securities in the lowest rating categories, and unrated securities
that Loomis Sayles determines to be of comparable quality.     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
 
                                      11
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
   <S>                                                          <C>      <C>
   AAA/Aaa.....................................................     %        %
   AA/Aa.......................................................
   A/A.........................................................
   BBB/Baa.....................................................
   BB/Ba.......................................................
   B/B.........................................................
   CCC/Caa.....................................................
   C/Ca........................................................
   D...........................................................
</TABLE>    
 
LOOMIS SAYLES GLOBAL BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of high current income and capital appreciation.
   
  The Fund seeks to achieve its objective by investing primarily in investment
grade fixed income securities denominated in various currencies, including
U.S. dollars, or in multicurrency units. Under normal conditions, the Fund
will invest at least 65% of its total assets in fixed income securities of
issuers from at least three countries, which may include the United States,
and no more than 40% of its total assets in issuers headquartered in any one
country. However, up to 100% of the Fund's total assets may be denominated in
U.S. dollars. The Fund may also invest up to 20% of its total assets in
securities of below investment grade quality (commonly known as "junk bonds").
The fixed income securities in which the Fund may invest include corporate
securities, U.S. Government Securities, commercial paper, zero coupon
securities, mortgage-backed securities, CMOs, asset-backed securities, when-
issued securities, Rule 144A securities, repurchase agreements and convertible
securities. The Fund may engage in options and futures transactions,
repurchase transactions, foreign currency hedging transactions and swap
transactions.     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
   <S>                                                          <C>      <C>
   AAA/Aaa.....................................................     %        %
   AA/Aa.......................................................
   A/A.........................................................
   BBB/Baa.....................................................
   BB/Ba.......................................................
   B/B.........................................................
   CCC/Caa.....................................................
   C/Ca........................................................
   D...........................................................
</TABLE>    
 
                                      12
<PAGE>
 
       
LOOMIS SAYLES INTERMEDIATE MATURITY BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
   
  The Fund seeks to achieve its objective by normally investing at least 90%
of its total assets in fixed income securities of investment grade quality and
to maintain an average dollar weighted maturity of between three and ten
years. For purposes of the 90% test, a security will be treated as being of
investment grade quality if it is rated by at least one major rating agency in
one of its top four rating categories at the time of purchase or, if unrated,
is determined by Loomis Sayles to be of comparable quality. The Fund may also
invest up to 10% of its total assets in fixed income securities of below
investment grade quality (commonly known as "junk bonds"). The fixed income
securities in which the Fund may invest include corporate securities, U.S.
Government Securities, commercial paper, zero coupon securities, mortgage-
backed securities, CMOs, asset-backed securities, when-issued securities,
REITs, Rule 144A securities, repurchase agreements and convertible securities.
The Fund may engage in options and futures transactions, repurchase
transactions, foreign currency hedging transactions, swap transactions and
securities lending. The Fund may invest any portion of its assets in
securities of Canadian issuers and up to 20% of its total assets in securities
of other foreign issuers.     
   
  The percentages of the Fund's assets invested as of September 30, 1998 in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
   <S>                                                          <C>      <C>
   AAA/Aaa.....................................................     %        %
   AA/Aa.......................................................
   A/A.........................................................
   BBB/Baa.....................................................
   BB/Ba.......................................................
   B/B.........................................................
   CCC/Caa.....................................................
   C/Ca........................................................
   D...........................................................
</TABLE>    
 
LOOMIS SAYLES INVESTMENT GRADE BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation.
 
                                      13
<PAGE>
 
   
  The Fund seeks to achieve its objective by normally investing at least 65%
of its total assets in fixed income securities of investment grade quality. Up
to 20% of the Fund's total assets may be invested in preferred stocks. The
Fund may also invest up to 10% of its total assets in fixed income securities
of below investment grade quality (commonly known as "junk bonds"). The fixed
income securities in which the Fund may invest include corporate securities,
U.S. Government Securities, commercial paper, zero coupon securities,
mortgage-backed securities, CMOs, asset-backed securities, when-issued
securities, REITs, Rule 144A securities, repurchase agreements and convertible
securities. The Fund may engage in options and futures transactions,
repurchase transactions, foreign currency hedging transactions, swap
transactions and securities lending. The Fund may invest any portion of its
assets in securities of Canadian issuers and up to 20% of its total assets in
the securities of other foreign issuers.     
   
  The percentages of the Fund's assets invested as of September 30, 1998, in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
 
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
   <S>                                                          <C>      <C>
   AAA/Aaa.....................................................     %        %
   AA/Aa.......................................................
   A/A.........................................................
   BBB/Baa.....................................................
   BB/Ba.......................................................
   B/B.........................................................
   CCC/Caa.....................................................
   C/Ca........................................................
   D...........................................................
</TABLE>    
 
LOOMIS SAYLES MUNICIPAL BOND FUND
 
  The Fund's investment objective is as high a level of current income exempt
from federal income tax as is consistent with the preservation of capital.
   
  The Fund seeks to achieve its objective by normally investing substantially
all of its assets in securities the income from which is, in the opinion of
issuer's counsel at the time of issuance, exempt from federal income tax ("tax
exempt securities"). It is a fundamental policy of the Fund that, during
periods of normal market conditions, at least 80% of its net assets will be
invested in tax exempt securities. Normally, substantially all of its market
value will be invested in fixed income securities of investment grade quality
(i.e., securities rated at the time of purchase by at least one of the major
rating agencies in its top four categories) or in unrated securities
determined by Loomis Sayles to be     
 
                                      14
<PAGE>
 
   
of comparable quality, and at least 65% of the Fund's total assets will be
invested in bonds. The Fund may engage in options and futures transactions.
       
  The Fund may invest in "private activity bonds," which pay interest that,
although exempt from ordinary federal income taxes, may be subject to federal
or state alternative minimum taxes. The Fund's investments in private activity
bonds normally will not exceed 20% of its net assets.     
 
LOOMIS SAYLES SHORT-TERM BOND FUND
 
  The Fund's investment objective is high total investment return through a
combination of current income and capital appreciation with relatively low
fluctuation in net asset value.
   
  The Fund seeks to achieve its objective by normally investing substantially
all of its assets in fixed income securities, although up to 20% of its total
assets may be invested in non-convertible preferred stock. At least 65% of the
Fund's total assets will normally be invested in bonds with a remaining
maturity of 5 years or less. The Fund may invest up to 20% of its total assets
in securities of foreign issuers. The Fund may also invest up to 20% of its
total assets in securities of below investment grade quality (commonly known
as "junk bonds"). The fixed income securities in which the Fund may invest
include corporate securities, U.S. Government Securities, commercial paper,
zero coupon securities, mortgage-backed securities, CMOs, asset-backed
securities, when-issued securities, REITs, Rule 144A securities, repurchase
agreements and convertible securities. The Fund may engage in options and
futures transactions, repurchase transactions, foreign currency hedging
transactions and swap transactions.     
 
  In an effort to minimize fluctuations in market value, the Fund is expected
to maintain an average dollar-weighted maturity of between one and three
years.
   
  The percentages of the Fund's assets invested as of September 30, 1998 in
securities assigned to the various rating categories by Standard & Poor's and
Moody's Investors Service, Inc. ("Moody's") at the time of purchase or, if
unrated, determined by Loomis Sayles to be of comparable quality, were as
follows:     
<TABLE>   
<CAPTION>
                                                                STANDARD
                                                                & POOR'S MOODY'S
                                                                -------- -------
   <S>                                                          <C>      <C>
   AAA/Aaa.....................................................     %        %
   AA/Aa.......................................................
   A/A.........................................................
   BBB/Baa.....................................................
   BB/Ba.......................................................
   B/B.........................................................
   CCC/Caa.....................................................
   C/Ca........................................................
   D...........................................................
</TABLE>    
 
                                      15
<PAGE>
 
ALL FUNDS
 
  For temporary defensive purposes, each Fund may invest any portion of its
assets in fixed income securities, cash or any other securities deemed
appropriate by Loomis Sayles.
 
  Except for each Fund's investment objective, and any investment policies
that are identified as "fundamental," all of the investment policies of each
Fund may be changed without a vote of Fund shareholders.
 
                 MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS
                            AND RISK CONSIDERATIONS
 
DEBT AND OTHER FIXED INCOME SECURITIES
 
  Each of the Funds may invest in fixed income securities of any maturity,
although the Short-Term Bond Fund expects to maintain an average dollar
weighted maturity of less than three years, and the Intermediate Maturity Bond
Fund expects to maintain an average dollar weighted maturity of between three
and ten years. Fixed income securities pay a specified rate of interest or
dividends, or a rate that is adjusted periodically by reference to some
specified index or market rate. Fixed income securities include securities
issued by federal, state, local and foreign governments and related agencies,
and by a wide range of private issuers. Because interest rates vary, it is
impossible to predict the income of a Fund that invests in fixed income
securities for any particular period. The net asset value of such a Fund's
shares will vary as a result of changes in the value of the securities in the
Fund's portfolio.
 
  Fixed income securities are subject to market and credit risk. Market risk
relates to changes in a security's value as a result of changes in interest
rates generally. In general, the values of fixed income securities increase
when prevailing interest rates fall and decrease when interest rates rise.
Credit risk relates to the ability of the issuer to make payments of principal
and interest.
 
U.S. GOVERNMENT SECURITIES
 
  U.S. Government Securities have different kinds of government support. For
example, some U.S. Government Securities, such as U.S. Treasury bonds, are
supported by the full faith and credit of the United States, whereas certain
other U.S. Government Securities issued or guaranteed by federal agencies or
government-sponsored enterprises are not supported by the full faith and
credit of the United States.
 
  Although U.S. Government Securities generally do not involve the credit
risks associated with other types of fixed income securities, the market
values of U.S. Government Securities do go up and down as interest rates
change.
 
                                      16
<PAGE>
 
Thus, for example, the value of an investment in a Fund that holds U.S.
Government Securities may fall during times of rising interest rates. Yields
on U.S. Government Securities tend to be lower than those on corporate
securities of comparable maturities.
 
  Some U.S. Government Securities, such as Government National Mortgage
Association Certificates ("GNMA"), are known as "mortgage-backed" securities.
Interest and principal payments on the mortgages underlying mortgage-backed
U.S. Government Securities are passed through to the holders of the security.
If a Fund purchases mortgage-backed securities at a discount or a premium, the
Fund will recognize a gain or loss when the payments of principal, through
prepayment or otherwise, are passed through to the Fund and, if the payment
occurs in a period of falling interest rates, the Fund may not be able to
reinvest the payment at as favorable an interest rate. As a result of these
principal prepayment features, mortgage-backed securities are generally more
volatile investments than many other fixed income securities.
 
  In addition to investing directly in U.S. Government Securities, the Funds
may purchase certificates of accrual or similar instruments ("strips")
evidencing undivided ownership interests in interest payments or principal
payments, or both, in U.S. Government Securities. These investment instruments
may be highly volatile.
 
TAX EXEMPT SECURITIES
 
  Issuers of tax exempt securities may make interest and principal payments
from money raised through a variety of sources, including (1) the issuer's
general taxing power, (2) a specific type of tax, such as a property tax, or
(3) a particular facility or project, such as a highway. The ability of an
issuer of tax exempt bonds to make these payments could be affected by
litigation, legislation or other political events, or the bankruptcy of the
issuer. The interest on tax exempt securities issued after August 15, 1986 is
retroactively taxable from the date of issuance if the issuer does not comply
with certain requirements concerning the use of bond proceeds and the
application of earnings on bond proceeds.
 
LOWER RATED FIXED INCOME SECURITIES
   
  Each Fund (other than the Municipal Bond Fund) may invest a portion of its
total assets in securities rated below investment grade (commonly referred to
as "junk bonds"). The Bond Fund may invest up to 35%, the Global Bond and
Short-Term Bond Funds each may invest up to 20%, the Investment Grade Bond and
Intermediate Maturity Bond Funds each may invest up to 10% of its total     
 
                                      17
<PAGE>
 
assets in such securities. For purposes of the foregoing percentages, a
security will be treated as being of investment grade quality if at the time a
Fund acquires it at least one major rating agency has rated the security in
its top four rating categories (even if another such agency has issued a lower
rating), or if the security is unrated but Loomis Sayles determines it to be
of investment grade quality. Lower rated fixed income securities generally
provide higher yields, but are subject to greater credit and market risk, than
higher quality fixed income securities. Lower rated fixed income securities
are considered predominantly speculative with respect to the ability of the
issuer to meet principal and interest payments. Achievement of the investment
objective of a Fund investing in lower rated fixed income securities may be
more dependent on Loomis Sayles' own credit analysis than is the case with
higher quality bonds. The market for lower rated fixed income securities may
be more severely affected than some other financial markets by economic
recession or substantial interest rate increases, by changing public
perceptions of this market or by legislation that limits the ability of
certain categories of financial institutions to invest in these securities. In
addition, the secondary market may be less liquid for lower rated fixed income
securities. This lack of liquidity at certain times may affect the values of
these securities and may make the evaluation and sale of these securities more
difficult. Securities in the lowest rating categories may be in poor standing
or in default. Securities in the lowest investment grade category (BBB or Baa)
have some speculative characteristics.
 
  For more information about the ratings services' descriptions of the various
rating categories, see Appendix A.
 
COMMON STOCKS AND OTHER EQUITY SECURITIES
 
  Common stocks and similar equity securities, such as warrants and
convertibles, are volatile and more risky than some other forms of investment.
The value of an investment in a Fund that invests in equity securities may
sometimes decrease. Equity securities of companies with relatively small
market capitalization may be more volatile than the securities of larger, more
established companies and than the broad equity market indexes.
 
ZERO COUPON SECURITIES
 
  Each Fund may invest in "zero coupon" fixed income securities. These
securities accrue interest at a specified rate, but do not pay interest in
cash on a current basis. A Fund investing in zero coupon securities is
required to distribute the income on these securities to Fund shareholders as
the income accrues, even though the Fund is not receiving the income in cash
on a current basis. Thus the Fund may have to sell other investments to obtain
cash to make income distributions at times when Loomis Sayles would not
otherwise deem it advisable to do so. The market value of zero coupon
securities is often more volatile than that of non-zero coupon fixed income
securities of comparable quality and maturity.
 
                                      18
<PAGE>
 
MORTGAGE-BACKED SECURITIES
   
  Each Fund (except the Municipal Bond Fund) may invest in mortgage-backed
securities, such as GNMA or Fannie Mae certificates, which differ from
traditional debt securities. Among the major differences are that interest and
principal payments are made more frequently, usually monthly, and that
principal may be prepaid at any time because the underlying mortgage loans
generally may be prepaid at any time. As a result, if a Fund purchases these
assets at a premium, a faster-than-expected prepayment rate will reduce yield
to maturity, and a slower-than-expected prepayment rate will increase yield to
maturity. If a Fund purchases mortgage-backed securities at a discount,
faster-than-expected prepayments will increase, and slower-than-expected
prepayments will reduce, yield to maturity. Prepayments, and resulting amounts
available for reinvestment by the Fund, are likely to be greater during a
period of declining interest rates and, as a result, are likely to be
reinvested at lower interest rates. Accelerated prepayments on securities
purchased at a premium may result in a loss of principal if the premium has
not been fully amortized at the time of prepayment. Although these securities
will decrease in value as a result of increases in interest rates generally,
they are likely to appreciate less than other fixed-income securities when
interest rates decline because of the risk of prepayments.     
 
STRIPPED MORTGAGE-BACKED SECURITIES
 
  Each Fund may invest in interest-only and principal-only classes of
mortgage-backed securities ("IOs" and "POs"). The yield to maturity on an IO
or PO is extremely sensitive not only to changes in prevailing interest rates
but also to the rate of principal payments (including prepayments) on the
underlying assets. A rapid rate of principal prepayments may have a measurably
adverse effect on a Fund's yield to maturity to the extent it invests in IOs.
If the assets underlying the IOs experience greater than anticipated
prepayments of principal, the Fund may fail to recoup fully its initial
investment in these securities. Conversely, POs tend to increase in value if
prepayments are greater than anticipated and decline if prepayments are slower
than anticipated.
 
  The secondary market for stripped mortgage-backed securities may be more
volatile and less liquid than that for other mortgage-backed securities,
potentially limiting a Fund's ability to buy or sell those securities at any
particular time.
 
COLLATERALIZED MORTGAGE OBLIGATIONS
 
  Each Fund (except the Municipal Bond Fund) may invest in CMOs. A CMO is a
security backed by a portfolio of mortgages or mortgage-backed securities held
under an indenture. CMOs may be issued either by U.S. Government
instrumentalities or by non-governmental entities. The issuer's
 
                                      19
<PAGE>
 
obligation to make interest and principal payments is secured by the
underlying portfolio of mortgages or mortgage-backed securities. CMOs are
issued with a number of classes or series which have different maturities and
which may represent interests in some or all of the interest or principal on
the underlying collateral or a combination thereof. CMOs of different classes
are generally retired in sequence as the underlying mortgage loans in the
mortgage pool are repaid. In the event of sufficient early prepayments on such
mortgages, the class or series of CMOs first to mature generally will be
retired prior to its maturity. As with other mortgage-backed securities, the
early retirement of a particular class or series of CMOs held by a Fund could
involve the loss of any premium the Fund paid when it acquired the investment
and could result in the Fund's reinvesting the proceeds at a lower interest
rate than the retired CMO paid. Because of the early retirement feature, CMOs
may be more volatile than many other fixed-income investments.
 
ASSET-BACKED SECURITIES
   
  Each Fund (except the Municipal Bond Fund) may invest in asset-backed
securities. Through the use of trusts and special purpose corporations,
automobile and credit card receivables are securitized in pass-through
structures similar to mortgage pass-through structures or in a pass-through
structure similar to the CMO structure. Generally, the issuers of asset-backed
bonds, notes or pass-through certificates are special purpose entities and do
not have any significant assets other than the receivables securing such
obligations. In general, the collateral supporting asset-backed securities is
of shorter maturity than mortgage loans. Instruments backed by pools of
receivables are similar to mortgage-backed securities in that they are subject
to unscheduled prepayments of principal prior to maturity. When the
obligations are prepaid, the Fund will ordinarily reinvest the prepaid amounts
in securities the yields of which reflect interest rates prevailing at the
time. Therefore, a Fund's ability to maintain a portfolio that includes high-
yielding asset-backed securities will be adversely affected to the extent that
prepayments of principal must be reinvested in securities that have lower
yields than the prepaid obligations. Moreover, prepayments of securities
purchased at a premium could result in a realized loss.     
 
WHEN-ISSUED SECURITIES
 
  Each Fund may purchase securities on a "when-issued" basis. This means that
the Fund will enter into a commitment to buy the security before the security
has been issued. The Fund's payment obligation and the interest rate on the
security are determined when the Fund enters into the commitment. The security
is typically delivered to the Fund 15 to 120 days later. No interest accrues
on the security between the time the Fund enters into the commitment and the
time the security is delivered. If the value of the security being
 
                                      20
<PAGE>
 
purchased falls between the time a Fund commits to buy it and the payment
date, the Fund may sustain a loss. The risk of this loss is in addition to the
Fund's risk of loss on the securities actually in its portfolio at the time.
In addition, when the Fund buys a security on a when-issued basis, it is
subject to the risk that market rates of interest will increase before the
time the security is delivered, with the result that the yield on the security
delivered to the Fund may be lower than the yield available on other,
comparable securities at the time of delivery. If a Fund has outstanding
obligations to buy when-issued securities, it will maintain liquid assets in a
segregated account at its custodian bank in an amount sufficient to satisfy
these obligations.
   
CONVERTIBLE SECURITIES     
   
  Convertible securities include corporate bonds, notes or preferred stocks of
U.S. or foreign issuers that can be converted into (that is, exchanged for)
common stocks or other equity securities at a stated price or rate.
Convertible securities also include other securities, such as warrants, that
provide an opportunity for equity participation. Because convertible
securities can be converted into equity securities, their value will normally
vary in some proportion with those of the underlying equity securities.
Convertible securities usually provide a higher yield than the underlying
equity security, however, so that when the price of the underlying equity
security falls, the decline in the price of the convertible security may
sometimes be less substantial than that of the underlying equity security. Due
to the conversion feature, convertible securities generally yield less than
nonconvertible fixed income securities of similar credit quality and maturity.
The Fund's investment in convertible securities may at times include
securities that have a mandatory conversion feature, pursuant to which the
securities convert automatically into common stock at a specified date and
conversion ratio, or that are convertible at the option of the issuer. Because
conversion is not at the option of the holder, the Fund may be required to
convert the security into the underlying common stock even at times when the
value of the underlying common stock has declined substantially.     
   
REAL ESTATE INVESTMENT TRUSTS     
   
  The Funds may invest in REITs. REITs involve certain unique risks in
addition to those risks associated with investing in the real estate industry
in general (such as possible declines in the value of real estate, lack of
availability of mortgage funds or extended vacancies of property). Equity
REITs may be affected by changes in the value of the underlying property owned
by the REITs, while mortgage REITs may be affected by the quality of any
credit extended. REITs are dependent upon management skills, are not
diversified, are subject to heavy cash flow dependency, risks of default by
borrowers and self-liquidation.     
 
                                      21
<PAGE>
 
   
REITs are also subject to the possibilities of failing to qualify for tax-free
pass-through of income under the Code, and failing to maintain their
exemptions from registration under the Investment Company Act of 1940 (the
"1940 Act").     
   
  Investment in REITs involves risk similar to those associated with investing
in small capitalization companies. REITs may have limited financial resources,
may trade less frequently and in a limited volume and may be subject to more
abrupt or erratic price movements than larger securities.     
 
RULE 144A SECURITIES
 
  Each Fund may invest in Rule 144A securities, which are privately offered
securities that can be resold only to certain qualified institutional buyers.
Rule 144A securities are treated as illiquid, unless Loomis Sayles has
determined, under guidelines established by the Trust's trustees, that the
particular issue of Rule 144A securities is liquid.
 
FOREIGN SECURITIES
   
  Each Fund (except the Municipal Bond Fund) may invest in securities of
issuers organized or headquartered outside the United States ("foreign
securities"). The Short-Term Bond Fund will not purchase a foreign security
if, as a result, the Fund's holdings of foreign securities would exceed 20% of
the Fund's total assets. Each of the Bond, Intermediate Maturity Bond and
Investment Grade Bond Funds may each invest any portion of its assets in
securities of Canadian issuers, but will not purchase foreign securities other
than those of Canadian issuers if, as a result, such Fund's holdings of non-
U.S. and non-Canadian securities would exceed 20% of the Fund's total assets.
    
  Although investing in foreign securities may increase a Fund's
diversification and reduce portfolio volatility, foreign securities may
present risks not associated with investments in comparable securities of U.S.
issuers. There may be less information publicly available about a foreign
corporate or government issuer than about a U.S. issuer, and foreign corporate
issuers are not generally subject to accounting, auditing and financial
reporting standards and practices comparable to those in the United States.
The securities of some foreign issuers are less liquid and at times more
volatile than securities of comparable U.S. issuers. Foreign brokerage
commissions and securities custody costs are often higher than in the United
States. With respect to certain foreign countries, there is a possibility of
governmental expropriation of assets, confiscatory taxation, political or
financial instability and diplomatic developments that could affect the value
of investments in those countries. A Fund's receipt of interest on foreign
government securities may depend on the availability of tax or other revenues
to satisfy the issuer's obligations.
 
                                      22
<PAGE>
 
  A Fund's investments in foreign securities may include investments in
countries whose economies or securities markets are not yet highly developed.
Special considerations associated with these investments (in addition to the
considerations regarding foreign investments generally) may include, among
others, greater political uncertainties, an economy's dependence on revenues
from particular commodities or on international aid or development assistance,
currency transfer restrictions, highly limited numbers of potential buyers for
such securities and delays and disruptions in securities settlement
procedures.
 
  Since most foreign securities are denominated in foreign currencies or
traded primarily in securities markets in which settlements are made in
foreign currencies, the value of these investments and the net investment
income available for distribution to shareholders of a Fund investing in these
securities may be affected favorably or unfavorably by changes in currency
exchange rates, exchange control regulations or foreign withholding taxes.
Changes in the value relative to the U.S. dollar of a foreign currency in
which a Fund's holdings are denominated will result in a change in the U.S.
dollar value of the Fund's assets and the Fund's income available for
distribution.
 
  In addition, although part of a Fund's income may be received or realized in
foreign currencies, the Fund will be required to compute and distribute its
income in U.S. dollars. Therefore, if the value of a currency relative to the
U.S. dollar declines after the Fund's income has been earned in that currency,
translated into U.S. dollars and declared as a dividend, but before payment of
the dividend, the Fund could be required to liquidate portfolio securities to
pay the dividend. Similarly, if the value of a currency relative to the U.S.
dollar declines between the time the Fund accrues expenses in U.S. dollars and
the time such expenses are paid, the amount of such currency required to be
converted into U.S. dollars will be greater than the equivalent amount in such
currency of such expenses at the time they were incurred.
 
  In determining whether to invest assets of the Funds in securities of a
particular foreign issuer, Loomis Sayles will consider the likely effects of
foreign taxes on the net yield available to the Fund and its shareholders.
Compliance with foreign tax law may reduce a Fund's net income available for
distribution to shareholders.
 
FOREIGN CURRENCY HEDGING TRANSACTIONS
 
  The Funds may engage in foreign currency exchange transactions to protect
the value of specific portfolio positions or in anticipation of changes in
relative values of currencies in which current or future Fund portfolio
holdings are denominated or quoted. For example, to protect against a change
in the foreign currency exchange rate between the date on which a Fund
contracts to purchase or sell a security and the settlement date for the
purchase or sale, or to "lock
 
                                      23
<PAGE>
 
in" the equivalent of a dividend or interest payment in another currency, a
Fund might purchase or sell a foreign currency on a spot (that is, cash) basis
at the prevailing spot rate. If conditions warrant, the Funds may also enter
into private contracts to purchase or sell foreign currencies at a future date
("forward contracts"). The Funds might also purchase exchange-listed and over-
the-counter call and put options on foreign currencies. Over-the-counter
currency options are generally less liquid than exchange-listed options, and
will be treated as illiquid assets. The Funds may not be able to dispose of
over-the-counter options readily.
 
  Foreign currency transactions involve costs and may result in losses.
 
SWAP TRANSACTIONS
 
  The Funds may enter into interest rate or currency swaps. The Funds will
enter into these transactions primarily to preserve a return or spread on a
particular investment or portion of its portfolio, to protect against currency
fluctuations, as a duration management technique or to protect against any
increase in the price of securities a Fund anticipates purchasing at a later
date. Interest rate swaps involve the exchange by a Fund with another party of
their respective commitments to pay or receive interest (for example, an
exchange of floating rate payments for fixed rate payments with respect to a
notional amount of principal). A currency swap is an agreement to exchange
cash flows on a notional amount based on changes in the relative values of the
specified currencies. The Fund will maintain liquid assets in a segregated
custodial account to cover its current obligations under swap agreements.
Because swap agreements are not exchange-traded, but are private contracts
into which the Fund and a swap counterparty enter as principals, the Fund may
experience a loss or delay in recovering assets if the counterparty were to
default on its obligations.
 
OPTIONS AND FUTURES TRANSACTIONS
   
  The Funds may buy, sell or write options on securities, securities indexes,
currencies or futures contracts and may buy and sell futures contracts on
securities, securities indexes or currencies. The Funds may engage in these
transactions either for the purpose of enhancing investment return, or to
hedge against changes in the value of other assets that the Funds own or
intend to acquire. Options and futures fall into the broad category of
financial instruments known as "derivatives" and involve special risks. Use of
options or futures for other than hedging purposes may be considered a
speculative activity, involving greater risks than are involved in hedging.
    
  Options can generally be classified as either "call" or "put" options. There
are two parties to a typical options transaction: the "writer" and the
 
                                      24
<PAGE>
 
"buyer." A call option gives the buyer the right to buy a security or other
asset (such as an amount of currency or a futures contract) from, and a put
option gives the buyer the right to sell a security or other asset to, the
option writer at a specified price, on or before a specified date. The buyer
of an option pays a premium when purchasing the option, which reduces the
return on the underlying security or other asset if the option is exercised,
and results in a loss if the option expires unexercised. The writer of an
option receives a premium from writing an option, which may increase its
return if the option expires or is closed out at a profit. If a Fund as the
writer of an option is unable to close out an unexpired option, it must
continue to hold the underlying security or other asset until the option
expires, to "cover" its obligation under the option.
 
  A futures contract creates an obligation by the seller to deliver and the
buyer to take delivery of the type of instrument or cash at the time and in
the amount specified in the contract. Although many futures contracts call for
the delivery (or acceptance) of the specified instrument, futures are usually
closed out before the settlement date through the purchase (or sale) of a
comparable contract. If the price of the sale of the futures contract by a
Fund exceeds (or is less than) the price of the offsetting purchase, the Fund
will realize a gain (or loss).
 
  The value of options purchased by a Fund and futures contracts held by a
Fund may fluctuate based on a variety of market and economic factors. In some
cases, the fluctuations may offset (or be offset by) changes in the value of
securities held in a Fund's portfolio. All transactions in options and futures
involve the possible risk of loss to the Fund of all or a significant part of
the value of its investment. In some cases, the risk of loss may exceed the
amount of the Fund's investment. When a Fund writes a call option or sells a
futures contract without holding the underlying securities, currencies or
futures contracts, its potential loss is unlimited. The Fund will be required,
however, to set aside with its custodian bank liquid assets in amounts
sufficient at all times to satisfy its obligations under options and futures
contracts.
 
  The successful use of options and futures will usually depend on Loomis
Sayles' ability to forecast stock market, currency or other financial market
movements correctly. The Fund's ability to hedge against adverse changes in
the value of securities held in its portfolio through options and futures also
depends on the degree of correlation between changes in the value of futures
or options positions and changes in the values of the portfolio securities.
The successful use of futures and exchange traded options also depends on the
availability of a liquid secondary market to enable a Fund to close its
positions on a timely basis. There can be no assurance that such a market will
exist at any particular time. In the case of options that are not traded on an
exchange ("over-the-counter" options), a Fund is at risk that the other party
to the transaction will default on its obligations, or will not permit a Fund
to terminate the transaction before its
 
                                      25
<PAGE>
 
scheduled maturity. As a result of these characteristics, each Fund will treat
most over-the-counter options (and the assets it segregates to cover its
obligations thereunder) as illiquid.
 
  The options and futures markets of foreign countries are small compared to
those of the United States and consequently are characterized in most cases by
less liquidity than are the U.S. markets. In addition, foreign markets may be
subject to less detailed reporting requirements and regulatory controls than
U.S. markets. Furthermore, investments in options in foreign markets are
subject to many of the same risks as other foreign investments. See "Foreign
Securities" above.
 
REPURCHASE AGREEMENTS
 
  Each Fund may invest in repurchase agreements. In repurchase agreements, a
Fund buys securities from a seller, usually a bank or brokerage firm, with the
understanding that the seller will repurchase the securities at a higher price
at a later date. Such transactions afford an opportunity for a Fund to earn a
return on available cash at minimal market risk, although the Fund may be
subject to various delays and risks of loss if the seller is unable to meet
its obligations to repurchase.
 
SECURITIES LENDING
 
  The Intermediate Maturity Bond and Investment Grade Bond Funds may lend
their portfolio securities to broker-dealers or other parties under contracts
calling for the deposit by the borrower with the Fund's custodian of cash
collateral equal to at least the market value of the securities loaned, marked
to market on a daily basis. The Fund will continue to benefit from interest or
dividends on the securities loaned and will also receive interest through
investment of the cash collateral in short-term liquid investments. No loans
will be made if, as a result, the aggregate amount of such loans outstanding
at any time would exceed 33 1/3% of the Fund's total assets (taken at current
value). Any voting rights, or rights to consent, relating to securities loaned
pass to the borrower. However, if a material event affecting the investment
occurs, such loans will be called so that the securities may be voted by the
Fund. The Fund pays various fees in connection with such loans, including
shipping fees and reasonable custodial or placement fees.
 
  Securities loans must be fully collateralized at all times, but involve some
credit risk to the Fund if the borrower defaults on its obligation and the
Fund is delayed or prevented from recovering the collateral.
 
YEAR 2000
 
  Many computer software systems in use today cannot properly process date-
related information from and after January 1, 2000. Should any of the
 
                                      26
<PAGE>
 
computer systems employed by the Funds' major service providers fail to
process this type of information properly, that could have a negative impact
on the Funds' operations and the services that are provided to the Funds'
shareholders. Loomis Sayles and the Distributor have each advised the Funds
that they are reviewing all of their computer systems with the goal of
modifying or replacing such systems prior to January 1, 2000, to the extent
necessary to foreclose any such negative impact. In addition, Loomis Sayles
has been advised by the Funds' custodian that it is also in the process of
reviewing its systems with the same goal. As of the date of this prospectus,
the Funds and Loomis Sayles have no reason to believe that these goals will
not be achieved. Similarly, the values of certain of the portfolio securities
held by the Funds may be adversely affected by the inability of the
securities' issuers or of third parties to process this type of information
properly.
 
                         THE FUNDS' INVESTMENT ADVISER
 
  The Funds' investment adviser is Loomis Sayles, One Financial Center,
Boston, Massachusetts 02111. Founded in 1926, Loomis Sayles is one of the
country's oldest and largest investment firms. The general partner of Loomis
Sayles is a special purpose corporation that is an indirect wholly-owned
subsidiary of Nvest Companies, L.P. ("Nvest Companies"). Nvest Companies'
managing general partner, Nvest Corporation, is a direct wholly-owned
subsidiary of Metropolitan Life Insurance Company ("Met Life"), a mutual life
insurance company. Nvest Companies' advising general partner, Nvest, L.P., is
a publicly traded company listed on the New York Stock Exchange. Nvest
Corporation is the sole general partner of Nvest L.P.
 
  In addition to selecting and reviewing the Funds' investments, Loomis Sayles
provides executive and other personnel for the management of the Funds. The
Funds' board of trustees supervises Loomis Sayles' conduct of the affairs of
the Funds.
          
  As of October 31, 1998, Charles Schwab & Co. Inc. owned 48%, 40%, 55%, 27%,
and 21% of the Bond Fund, Global Bond Fund, Intermediate Maturity Bond Fund,
Investment Grade Bond Fund and Short-Term Bond Fund, respectively. As of
October 31, 1998, Fleet National Bank, Norwest Bank and San Diego Transit
Pension Plan owned 13%, 16%, and 8% of the Global Bond Fund, respectively. As
of October 31, 1998, Hawaii Sheet Metal Workers Health & Welfare Fund and
Pomona College owned 26% and 7% of the Intermediate Maturity Bond Fund,
respectively. As of October 31, 1998, Loomis Sayles & Company, L.P. owned 26%
of the Investment Grade Bond Fund, respectively. As of October 31, 1998, John
W. George, Jr. Trust and Anna A. Morris Trust owned 20% and 14% of the
Municipal Bond Fund, respectively. As of October 31, 1998, John W. George, Jr.
Trust, NFSC, and PAMCAH-UA Local 675 owned 6%, 14%, and 8% of the Short-Term
Bond Fund, respectively.
    
                                      27
<PAGE>
 
   
Shareholders holding more than 25% of a Fund's shares may be deemed to control
the relevant Fund.     
   
  Daniel J. Fuss, President of the Trust and Executive Vice President of
Loomis Sayles, has served as the portfolio manager of the Bond Fund since its
commencement of investment operations in 1991 and as the portfolio manager of
the Investment Grade Bond Fund since its commencement of investment operations
in 1997. Kathleen C. Gaffney, Vice President of the Trust and Loomis Sayles,
has served as associate portfolio manager of the Bond Fund since October 1997.
E. John deBeer, Vice President of the Trust and of Loomis Sayles, has served
as the portfolio manager of the Global Bond Fund since its commencement of
investment operations in 1991. Anthony J. Wilkins, Vice President of the Trust
and of Loomis Sayles, has served as the portfolio manager of the Intermediate
Maturity Bond Fund since its commencement of investment operations in 1997.
Martha F. Hodgman, Vice President of the Trust and of Loomis Sayles, has
served as the portfolio manager of the Municipal Bond Fund since May 1993.
John Hyll, Vice President of the Trust and of Loomis Sayles, has served as the
portfolio manager of the Short-Term Bond Fund since its commencement of
investment operations in 1992. Curt A. Mitchell, Vice President of Loomis
Sayles, has served as portfolio manager of the Short-Term Bond Fund since
October 1998. Each of the foregoing, except Mr. Mitchell, has been employed by
Loomis Sayles for at least five years. Before joining Loomis Sayles in 1995,
Mr. Mitchell was a portfolio manager at Firstar Research & Management Company.
    
                                 FUND EXPENSES
 
  Each Fund pays Loomis Sayles a monthly investment advisory fee at the
following annual percentage rates of the Fund's average daily net assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                     RATE
   ----                                                                     ----
   <S>                                                                      <C>
   Bond.................................................................... .60%
   Global Bond............................................................. .60%
   Intermediate Maturity Bond.............................................. .40%
   Investment Grade Bond................................................... .40%
   Municipal Bond.......................................................... .40%
   Short-Term Bond......................................................... .25%
</TABLE>    
 
  In addition to the investment advisory fee, each Fund pays all expenses not
expressly assumed by Loomis Sayles, including taxes, brokerage commissions,
fees and expenses of the registering or qualifying the Fund's shares under
federal and state securities laws, fees of the Fund's custodian, transfer
agent, independent accountants and legal counsel, expenses of shareholders'
and trustees' meetings, expenses of preparing, printing and mailing
prospectuses to shareholders and fees of trustees who are not directors,
officers or employees of Loomis Sayles or its affiliated companies.
 
                                      28
<PAGE>
 
  Loomis Sayles has voluntarily agreed, for an indefinite period, to reduce
its advisory fees and/or bear other Fund expenses to the extent necessary to
limit Fund total annual operating expenses of the Institutional Class shares
of each Fund to the following annual percentage rate of the Fund's average net
assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                     RATE
   ----                                                                     ----
   <S>                                                                      <C>
   Bond.................................................................... .75%
   Global Bond............................................................. .90%
   Intermediate Maturity Bond.............................................. .55%
   Investment Grade Bond................................................... .55%
   Municipal Bond.......................................................... .60%
   Short-Term Bond......................................................... .50%
</TABLE>    
 
  Loomis Sayles may change or terminate these voluntary arrangements at any
time, but the Funds' Prospectus would be supplemented to describe the change.
 
  Loomis Sayles may pay certain broker-dealers and financial intermediaries
whose customers own shares of the Funds a continuing fee in an amount of up to
 .25% annually of the value of Fund shares held for those customers' accounts.
These fees are paid by Loomis Sayles out of its own assets and are not
assessed against the Funds.
 
                            PORTFOLIO TRANSACTIONS
 
  Portfolio turnover considerations will not limit Loomis Sayles' investment
discretion in managing the Funds' assets. The Funds anticipate that their
portfolio turnover rates will vary significantly from time to time depending
on the volatility of economic and market conditions. High portfolio turnover
may involve higher costs and higher levels of taxable gains.
 
                            HOW TO PURCHASE SHARES
 
  An investor may make an initial purchase of shares of any Fund by submitting
a completed application form and payment to:
 
      Boston Financial Data Services
      P.O. Box 8314
      Boston, Massachusetts 02266-8314
      Attn: Loomis Sayles Funds
 
  The minimum initial investment for the Institutional Class of shares of the
Loomis Sayles Bond Fund is $25,000. The minimum initial investment for the
Institutional Class of each other Fund's shares is $1 million in that Fund. A
 
                                      29
<PAGE>
 
$2,500 minimum investment applies to the current and retired trustees of the
Trust, investment advisory clients of Loomis Sayles (and their directors,
officers and employees), and current and retired employees of Loomis Sayles
and the parents, spouses and children of the foregoing. The minimum investment
may be waived in whole or in part by Loomis Sayles in its sole discretion.
Subsequent investments must be at least $50.
 
  Shares of any Fund may be purchased by (i) cash, (ii) exchanging
Institutional Class shares of any Fund (or any other series of Loomis Sayles
Funds), provided the value of the shares exchanged meets the investment
minimum of the Fund into which the exchange is made, (iii) exchanging
securities on deposit with a custodian acceptable to Loomis Sayles or (iv) a
combination of such securities and cash. Loomis Sayles will not approve the
acceptance of securities in exchange for shares of any Fund unless (1) Loomis
Sayles, in its sole discretion, believes the securities are appropriate
investments for the Fund; (2) the investor represents and agrees that all
securities offered to the Fund can be resold by the Fund without restriction
under the Securities Act of 1933, as amended (the "Securities Act") or
otherwise; and (3) the securities are eligible to be acquired under the Fund's
investment policies and restrictions. No investor owning 5% or more of a
Fund's shares may purchase additional shares of that Fund by exchange of
securities.
 
  In all cases Loomis Sayles reserves the right to reject any securities that
are proposed for exchange. Securities accepted by Loomis Sayles in exchange
for Fund shares will be valued in the same manner as the Fund's assets as
described below as of the time of the Fund's next determination of net asset
value after such acceptance. All dividends and subscription or other rights
which are reflected in the market price of accepted securities at the time of
valuation become the property of the Fund and must be delivered to the Fund
upon receipt by the investor from the issuer. A gain or loss for federal
income tax purposes would be realized upon the exchange by an investor that is
subject to federal income taxation, depending upon the investor's basis in the
securities tendered. An investor who wishes to purchase shares by exchanging
securities should obtain instructions by calling 800-633-3330, option 5.
 
  All purchases made by check should be in U.S. dollars and made payable to
State Street Bank and Trust Company. Third party checks will not be accepted.
When purchases are made by check or periodic account investment, redemption
will not be allowed until the investment being redeemed has been in the
account for 15 calendar days.
 
  Upon acceptance of an investor's order, BFDS opens an account, applies the
payment to the purchase of full and fractional Fund shares and mails a
statement of the account confirming the transaction.
 
                                      30
<PAGE>
 
  After an account has been established, an investor may send subsequent
investments at any time directly to BFDS at the above address. The remittance
must be accompanied by either the account identification slip detached from a
statement of account or a note containing sufficient information to identify
the account, i.e., the Fund name and the investor's account number or name and
social security number.
 
  Subsequent investments can also be made by federal funds wire. Investors
should instruct their banks to wire federal funds to State Street Bank and
Trust Company, ABA #011000028. The text of the wire should read as follows:
"$    amount, STATE STREET BOS ATTN Mutual Funds. Credit Fund (Fund Name and
Institutional Class), DDA #9904-622-9, Account Name, Account Number." A bank
may charge a fee for transmitting funds by wire.
 
  Each Fund and the Distributor reserve the right to reject any purchase
order, including orders in connection with exchanges, for any reason which the
Fund or the Distributor in its sole discretion deems appropriate. Although the
Funds do not presently anticipate that they will do so, each Fund reserves the
right to suspend or change the terms of the offering of its shares.
 
  The price an investor pays will be the per share net asset value next
calculated after a proper investment order is received by the Trust's transfer
or other agent or subagent. Shares of each Fund are sold with no sales charge.
The net asset value of each Fund's shares is calculated once daily as of the
close of regular trading on the New York Stock Exchange on each day the
Exchange is open for trading, by dividing the Fund's net assets by the number
of shares outstanding. Portfolio securities are valued at their market value
as more fully described in the Statement of Additional Information.
 
  The Distributor may accept telephone orders from broker-dealers who have
been previously approved by the Distributor. It is the responsibility of such
broker-dealers to promptly forward purchase or redemption orders to the
Distributor. Although there is no sales charge imposed by the Fund or the
Distributor, broker-dealers may charge the investor a transaction-based fee or
other fee for their services at either the time of purchase or the time of
redemption. Such charges may vary among broker-dealers but in all cases will
be retained by the broker-dealer and not remitted to the Fund.
   
  Each Fund, except for the Municipal Bond Fund, also offers a Retail Class of
shares that has a $25,000, minimum investment for certain categories of
investors, is offered through intermediaries and bears higher expenses.
Because of its lower expenses, the Institutional Class of shares of each Fund
is expected to have a higher total return than the Retail Class of shares.
    
  The Loomis Sayles Bond Fund also offers an Admin Class of shares that is
offered exclusively through intermediaries, who will be the record owners of
the
 
                                      31
<PAGE>
 
shares. Because of its lower expenses, the Institutional Class of shares of
the Loomis Sayles Bond Fund is expected to have a higher total return than the
Admin Class of shares.
 
                             SHAREHOLDER SERVICES
 
  The Funds offer the following shareholder services, which are more fully
described in the Statement of Additional Information. Explanations and forms
are available from BFDS. Telephone redemption and exchange privileges will be
established automatically when an investor opens an account unless an investor
elects on the application to decline the privileges. Other privileges must be
specifically elected. A signature guarantee will be required to establish a
privilege after an account is opened.
   
  FREE EXCHANGE PRIVILEGE. The Institutional Class shares of any Fund may be
exchanged for Institutional Class shares of any other Fund (or any other fund
that is a series of Loomis Sayles Funds and that offers Institutional Class
shares) or for shares of certain money market funds advised by New England
Funds Management, L.P., an affiliate of Loomis Sayles, provided the value of
the shares exchanged meets the investment minimum of that Fund and, in the
case of the Loomis Sayles High Yield Fund and Loomis Sayles U.S. Government
Securities Fund, Loomis Sayles has approved the exchange of shares. Exchanges
may be made by written instructions or by telephone, unless an investor
elected on the application to decline telephone exchange privileges. The
exchange privilege should not be viewed as a means for taking advantage of
short-term swings in the market, and the Funds reserve the right to terminate
or limit the privilege of any shareholder who makes more than four exchanges
in any calendar year. The Funds may terminate or change the terms of the
exchange privilege at any time, upon 60 days' notice to shareholders. An
exchange is a taxable event for federal income tax purposes in which a gain or
loss would be realized by an investor that is subject to federal income
taxation.     
 
  RETIREMENT PLANS. The Funds' shares may be purchased by all types of tax-
deferred retirement plans. Loomis Sayles makes available retirement plan forms
for IRAs.
 
  SYSTEMATIC WITHDRAWAL PLAN. If the value of an account is at least $25,000,
an investor may have periodic cash withdrawals automatically paid to the
investor or any person designated by the investor.
 
  AUTOMATIC INVESTMENT PLAN. Voluntary monthly investments of at least $50 may
be made automatically by pre-authorized withdrawals from an investor's
checking account.
 
                                      32
<PAGE>
 
                             HOW TO REDEEM SHARES
 
  An investor can redeem shares by sending a written request to Boston
Financial Data Services, Inc., P.O. Box 8314, Boston, Massachusetts 02266.
Proceeds from a written request may be sent to the investor in the form of a
check. As described below, an investor may also redeem shares by calling BFDS
at 800-626-9390. Proceeds resulting from a telephone redemption request can be
wired to an investor's bank account or sent by check in the name of the
registered owners to their record address.
 
  The written request must include the name of the Fund, the account number,
the exact name(s) in which the shares are registered, and the number of shares
or the dollar amount to be redeemed. All owners of the shares must sign the
request in the exact names in which the shares are registered (this appears on
an investor's confirmation statement) and should indicate any special capacity
in which they are signing (such as trustee or custodian or on behalf of a
partnership, corporation or other entity). Shareholders requesting that
redemption proceeds be wired to their bank accounts must provide specific wire
instructions.
 
  If (1) an investor is redeeming shares worth more than $50,000, (2) an
investor is requesting that the proceeds check be made out to someone other
than the registered owners or be sent to an address other than the record
address, (3) the account registration has changed within the last 30 days or
(4) an investor is instructing us to wire the proceeds to a bank account not
designated on the application, the investor must have his or her signature
guaranteed by an eligible guarantor. This requirement may be waived by Loomis
Sayles in its sole discretion. Eligible guarantors include commercial banks,
trust companies, savings associations, credit unions and brokerage firms that
are members of domestic securities exchanges. Before submitting the redemption
request, an investor should verify with the guarantor institution that it is
an eligible guarantor. Signature guarantees by notaries public are not
acceptable.
 
  When an investor telephones a redemption request, the proceeds are wired to
the bank account previously chosen by the investor. A wire fee (currently $5)
will be deducted from the proceeds. A telephonic redemption request must be
received by BFDS prior to the close of regular trading on the New York Stock
Exchange. If an investor telephones a request to BFDS after the Exchange
closes or on a day when the Exchange is not open for business, BFDS cannot
accept the request and a new one will be necessary.
 
  If an investor decides to change the bank account to which proceeds are to
be wired, the investor must send in this change in writing with a signature
guarantee. Telephonic redemptions may only be made if the investor's bank is a
member of the Federal Reserve System or has a correspondent bank that is a
 
                                      33
<PAGE>
 
member of the System. Unless an investor indicates otherwise on the account
application, BFDS will be authorized to act upon redemption and exchange
instructions received by telephone from the investor or any person claiming to
act as the investor's representative who can provide BFDS with the investor's
account registration and address as it appears on the records of State Street
Bank. BFDS will employ these or other reasonable procedures to confirm that
instructions communicated by telephone are genuine; the Fund, State Street
Bank, BFDS, the Distributor and Loomis Sayles will not be liable for any
losses due to unauthorized or fraudulent instructions if these or other
reasonable procedures are followed. For information, consult BFDS. In times of
heavy market activity, an investor who encounters difficulty in placing a
redemption or exchange order by telephone may wish to place the order by mail
as described above.
   
  The redemption price will be the net asset value per share next determined
after the redemption request and any necessary special documentation are
received by BFDS in proper form.     
 
  Proceeds resulting from a written redemption request will normally be mailed
to an investor within seven days after receipt of the investor's request in
good order. Telephonic redemption proceeds will normally be wired to an
investor's bank on the first business day following receipt of a proper
redemption request. If an investor purchased shares by check and the check was
deposited less than 15 days prior to the redemption request, the Fund may
withhold redemption proceeds until the check has cleared.
 
  The Fund may suspend the right of redemption and may postpone payment for
more than seven days when the New York Stock Exchange is closed for other than
weekends or holidays, or if permitted by the rules of the SEC when trading on
the Exchange is restricted or during an emergency which makes it impracticable
for the Fund to dispose of its securities or to determine fairly the value of
its net assets, or during any other period permitted by the SEC for the
protection of investors.
 
                    CALCULATION OF PERFORMANCE INFORMATION
 
  The Funds' investment performance may from time to time be included in
advertisements about the Funds. "Yield" for each class of shares is calculated
by dividing the annualized net investment income per share during a recent 30-
day period by the maximum public offering price per share of the class on the
last day of that period.
 
  For purposes of calculating yield, net investment income is calculated in
accordance with SEC regulations and may differ from net investment income as
 
                                      34
<PAGE>
 
determined for financial reporting purposes. SEC regulations require that net
investment income be calculated on a "yield-to-maturity" basis, which has the
effect of amortizing any premiums or discounts in the current market value of
fixed income securities. The current dividend rate is based on net investment
income as determined for tax purposes, which may not reflect amortization in
the same manner.
       
  "Total return" for the one-, five- and ten-year periods (or for the life of
a class, if shorter) through the most recent calendar quarter represents the
average annual compounded rate of return on an investment of $1,000 in a Fund.
Total return may also be presented for other periods.
 
                DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES
   
  The Bond, Investment Grade Bond, and Intermediate Maturity Bond Funds
declare and pay dividends quarterly; the Global Bond Fund declares and pays
its net investment income to shareholders as dividends annually; the Municipal
Bond and Short-Term Bond Funds declare dividends daily and makes payments
monthly. Each Fund also distributes all of its net capital gains realized from
the sale of portfolio securities. Any capital gain distributions are normally
made annually, but may, to the extent permitted by law, be made more
frequently as deemed advisable by the trustees of the Trust. The Trust's
trustees may change the frequency with which the Funds declare or pay
dividends.     
   
  Dividends and capital gain distributions will automatically be reinvested in
additional shares of the same Fund unless an investor has elected to receive
cash.     
 
  Each Fund intends to qualify as a regulated investment company under the
Internal Revenue Code of 1986, as amended. As such, so long as a Fund
distributes substantially all its net investment income and net capital gains
to its shareholders, the Fund itself does not pay any federal income tax to
the extent such income and gains are so distributed.
   
  Except in the case of income dividends from tax exempt bond interest paid by
the Municipal Bond Fund (see below), an investor's income dividends and short-
term capital gain distributions are taxable as ordinary income whether
distributed in cash or additional shares. Distributions designated by a Fund
as deriving from net gains on securities held for more than one year will be
taxable as such (generally at a 20% rate for noncorporate shareholders)
whether distributed in cash or additional shares and regardless of how long an
investor has owned shares of the Fund.     
 
 
                                      35
<PAGE>
 
   
  A dividend or distribution made shortly after the purchase of shares of a
Fund by a shareholder, although in effect a return of capital to that
particular shareholder, would be taxable to him or her as described above. If
a shareholder held shares six months or less and during that period received a
distribution of net capital gains, any loss realized on the sale of such
shares during such six-month period would be a long-term capital loss to the
extent of such distribution.     
 
  Each Fund (except the Municipal Bond Fund in the case of designated exempt-
interest dividends, as described below) is required to withhold 31% of any
redemption proceeds (including the value of shares exchanged) and all income
dividends and capital gain distributions it pays (1) if an investor does not
provide a correct, certified taxpayer identification number, (2) if the Fund
is notified that an investor has underreported income in the past, or (3) if
an investor fails to certify to the Fund that he or she is not subject to such
withholding.
 
  Dividends derived from interest on U.S. Government Securities may be exempt
from state and local taxes.
 
  State Street Bank will send investors and the IRS an annual statement
detailing federal tax information, including information about dividends and
distributions paid during the preceding year. An investor should keep this
statement as a permanent record. A fee may be charged for any duplicate
information requested.
 
MUNICIPAL BOND FUND
 
  Certain designated dividends paid by the Municipal Bond Fund that are
derived from interest on tax exempt bonds ("exempt-interest dividends") may be
excluded from gross income on federal tax returns. However, if an investor
receives social security or railroad retirement benefits, the investor may be
taxed on a portion of those benefits as a result of receiving tax exempt
income. Also, tax exempt income may be taken into account for the federal
alternative minimum tax.
   
  An investor's income dividends and short-term capital gain distributions
(that is, net gains from securities held for not more than a year) are taxable
as ordinary income whether distributed in cash or additional shares.
Distributions designated by a Fund as deriving from net gains on securities
held for more than one year will be taxable as such whether distributed in
cash or additional shares and regardless of how long an investor has owned
shares of the Fund.     
 
  If at least 95% of the Fund's dividends are designated as exempt-interest
dividends, federal back-up withholding rules do not apply with respect to such
dividends.
 
                                      36
<PAGE>
 
  The federal exemption for exempt-interest dividends does not result in
exemption from state and local taxes. Distributions of exempt-interest
dividends may be exempt from local and state taxation to the extent they are
derived from the state or locality in which the investor resides. The Fund
will report annually on a state-by-state basis the source of income the Fund
received on tax exempt bonds that was paid out as dividends during the
preceding year.
 
NOTE:    The foregoing summarizes certain tax consequences of investing in the
         Funds. Before investing, an investor should consult his or her own tax
         adviser for more information concerning the federal, foreign, state and
         local tax consequences of investing in, redeeming or exchanging Fund
         shares.
                                               37
<PAGE>
 
                                                                     APPENDIX A
 
                    DESCRIPTION OF BOND RATINGS ASSIGNED BY
                             STANDARD & POOR'S AND
                        MOODY'S INVESTORS SERVICE, INC.
 
STANDARD & POOR'S
 
                                      AAA
 
  This is the highest rating assigned by Standard & Poor's to a debt
obligation and indicates an extremely strong capacity to pay interest and
repay principal.
 
                                      AA
 
  Bonds rated AA also qualify as high quality debt obligations. Capacity to
pay interest and repay principal is very strong, and in the majority of
instances they differ from AAA issues only in small degree.
 
                                       A
 
  Bonds rated A have a strong capacity to pay interest and repay principal,
although they are somewhat more susceptible to the adverse effects of changes
in circumstances and economic conditions than obligations in higher rated
categories.
 
                                      BBB
 
  Bonds rated BBB are regarded as having an adequate capacity to pay interest
and repay principal. Whereas they normally exhibit adequate protection
parameters, adverse economic conditions or changing circumstances are more
likely to lead to a weakened capacity to repay principal and pay interest for
bonds in this category than for bonds in higher rated categories.
 
                                BB, B, CCC, CC
 
  Bonds rated BB, B, CCC and CC are regarded, on balance, as predominantly
speculative with respect to capacity to pay interest and repay principal in
accordance with the terms of the obligation. BB indicates the lowest degree of
speculation and CC the highest degree of speculation. While such
 
                                      38
<PAGE>
 
bonds will likely have some quality and protective characteristics, these are
outweighed by large uncertainties or major risk exposures to adverse
conditions.
 
                                       C
 
  The rating C is reserved for income bonds on which no interest is being
paid.
 
                                       D
 
  Bonds rated D are in default, and payment of interest and/or repayment of
principal is in arrears.
 
                                       R
 
  This symbol is attached to the ratings of instruments with significant
noncredit risks such as risks to principal or volatility of expected returns.
 
  Plus (+) or Minus (-): The ratings from "AA" to "B" may be modified by the
addition of a plus or minus sign to show relative standing within the major
rating categories.
 
MOODY'S INVESTORS SERVICE, INC.
 
                                      AAA
 
  Bonds that are rated Aaa are judged to be of the best quality. They carry
the smallest degree of investment risk and are generally referred to as "gilt
edged." Interest payments are protected by a large, or by an exceptionally
stable, margin, and principal is secure. While the various protective elements
are likely to change, such changes as can be visualized are most unlikely to
impair the fundamentally strong position of such issues.
 
                                      AA
 
  Bonds that are rated Aa are judged to be high quality by all standards.
Together with the Aaa group they comprise what are generally known as high
grade bonds. They are rated lower than the best bonds because margins of
protection may not be as large as in Aaa securities or fluctuation of
protective elements may be of greater amplitude or there may be other elements
present that make the long-term risks appear somewhat larger than in Aaa
securities.
 
                                      39
<PAGE>
 
                                       A
 
  Bonds that are rated A possess many favorable investment attributes and are
to be considered as upper medium grade obligations. Factors giving security to
principal and interest are considered adequate, but elements may be present
that suggest a susceptibility to impairment sometime in the future.
 
                                      BAA
 
  Bonds that are rated Baa are considered as medium grade obligations; i.e.,
they are neither highly protected nor poorly secured. Interest payments and
principal security appear adequate for the present, but certain protective
elements may be lacking or may be characteristically unreliable over any great
length of time. Such bonds lack outstanding investment characteristics and, in
fact, have speculative characteristics as well.
 
                                      BA
 
  Bonds which are rated Ba are judged to have speculative elements; their
future cannot be considered as well assured. Often, the protection of interest
and principal payments may be very moderate, and thereby not well safeguarded
during both good and bad times over the future. Uncertainty of position
characterizes bonds in this class.
 
                                       B
 
  Bonds which are rated B generally lack characteristics of the desirable
investment. Assurance of interest and principal payments or of maintenance of
other terms of the contract over any long period of time may be small.
 
                                      CAA
 
  Bonds which are rated Caa are of poor standing. Such issues may be in
default or there may be present elements of danger with respect to principal
or interest.
 
                                      CA
 
  Bonds which are rated Ca represent obligations which are speculative in a
high degree. Such issues are often in default or have other marked
shortcomings.
 
                                      40
<PAGE>
 
                                       C
 
  Bonds which are rated C are the lowest rated class of bonds, and issues so
rated can be regarded as having extremely poor prospects of ever attaining any
real investment standing.
 
  Should no rating be assigned by Moody's, the reason may be one of the
following:
 
 1. An application for rating was not received or accepted.
 
 2. The issue or issuer belongs to a group of securities that are not rated
    as a matter of policy.
 
 3. There is a lack of essential data pertaining to the issue or issuer.
 
 4. The issue was privately placed in which case the rating is not published
    in Moody's publications.
 
  Suspension or withdrawal may occur if new and material circumstances arise,
the effects of which preclude satisfactory analysis; if there is no longer
available reasonable up-to-date data to permit a judgment to be formed; if a
bond is called for redemption; or for other reasons.
 
Note:  Those bonds in the Aa, A, Baa, Ba and B groups which Moody's believes
       possess the strongest investment attributes are designated by the symbols
       Aa1, A1, Baa1, Ba1 and B1.
        
                                      41
<PAGE>
 
INVESTMENT ADVISER Loomis, Sayles &
Company, L.P. One Financial Center Boston,
Massachusetts 02111
 
DISTRIBUTOR Loomis Sayles Distributors,
L.P. One Financial Center Boston,
Massachusetts 02111
 
TRANSFER AND DIVIDEND PAYING AGENT AND
CUSTODIAN OF ASSETS State Street Bank and
Trust Company Boston, Massachusetts 02102
 
SHAREHOLDER SERVICING AGENT FOR STATE
STREET BANK AND TRUST COMPANY Boston
Financial Data Services, Inc. P.O. Box 8314
Boston, Massachusetts 02266
 
LEGAL COUNSEL Ropes & Gray One
International Place Boston, Massachusetts
02110
   
INDEPENDENT ACCOUNTANTS
PricewaterhouseCoopers LLP One Post Office
Square Boston, Massachusetts 02109     
<PAGE>

[LOGO OF LOOMIS SAYLES APPEARS HERE] 
 
 One Financial Center . Boston, Massachusetts 02111 . (800) 633-3330
 
THE LOOMIS SAYLES FUNDS--EQUITY FUNDS
 
 INSTITUTIONAL CLASS SHARES OF:

    LOOMIS SAYLES CORE VALUE FUND
        
    LOOMIS SAYLES INTERNATIONAL EQUITY FUND
    LOOMIS SAYLES MID-CAP GROWTH FUND
    LOOMIS SAYLES MID-CAP VALUE FUND
    LOOMIS SAYLES SMALL CAP GROWTH FUND
    LOOMIS SAYLES SMALL CAP VALUE FUND
    LOOMIS SAYLES STRATEGIC VALUE FUND
    LOOMIS SAYLES WORLDWIDE FUND
<PAGE>
 
   
PROSPECTUS                                                 JANUARY 1, 1999     
 
THE LOOMIS SAYLES FUNDS--EQUITY FUNDS
   
  Loomis Sayles Core Value Fund, Loomis Sayles International Equity Fund, Loo-
mis Sayles Mid-Cap Growth Fund, Loomis Sayles Mid-Cap Value Fund, Loomis
Sayles Small Cap Growth Fund, Loomis Sayles Small Cap Value Fund, Loomis
Sayles Strategic Value Fund, and Loomis Sayles Worldwide Fund (the "Funds" and
each a "Fund"), each a series of Loomis Sayles Funds, are separately managed,
no-load mutual funds and each Fund has its own investment objective and poli-
cies. Loomis, Sayles & Company, L.P. ("Loomis Sayles") is the investment ad-
viser of each Fund.     
   
  The Funds offer two classes of shares: an Institutional Class that is de-
scribed in this Prospectus and a Retail Class, which generally has a lower
minimum investment and bears higher expenses, that is described in a separate
prospectus. The Loomis Sayles Small Cap Value Fund also offers a third class
of shares: an Admin Class, bearing higher expenses than the Institutional or
Retail Class, that is described in a separate prospectus. This Prospectus con-
cisely describes the information that an investor should know before investing
in the Institutional Class shares of any Fund. Please read it carefully and
keep it for future reference. A Statement of Additional Information (SAI)
dated January 1, 1999, as revised from time to time, is available free of
charge; write to Loomis Sayles Distributors, L.P. (the "Distributor"), One Fi-
nancial Center, Boston, Massachusetts 02111 or telephone 800-633-3330. The
SAI, which contains more detailed information about the Funds, has been filed
with the Securities and Exchange Commission (the "SEC") and is available along
with other related materials on the SEC's Internet Website
(http://www.sec.gov). The SAI is incorporated herein by reference (legally
forms a part of the prospectus). To obtain more information about the Retail
Class or Admin Class of shares, please call the Distributor toll-free at 800-
633-3330, contact your financial intermediary, or visit our Internet Website
at (http://www.loomissayles.com).     
 
  For information about:                    For all other information about
   .  Establishing an account               the Funds:
   .  Account procedures and status         CALL 800-633-3330
   .  Exchanges
   .  Shareholder services
  CALL 800-626-9390
 
THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES AND
EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS
A CRIMINAL OFFENSE.
 
 
                                       1
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>   
<CAPTION>
                                                                           PAGE
                                                                           ----
<S>                                                                        <C>
SUMMARY OF EXPENSES.......................................................   3
FINANCIAL HIGHLIGHTS......................................................   5
THE TRUST.................................................................  13
INVESTMENT OBJECTIVES AND POLICIES........................................  13
MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS AND RISK CONSIDERATIONS.....  16
THE FUNDS' INVESTMENT ADVISER.............................................  23
FUND EXPENSES.............................................................  25
PORTFOLIO TRANSACTIONS....................................................  26
HOW TO PURCHASE SHARES....................................................  26
SHAREHOLDER SERVICES......................................................  28
HOW TO REDEEM SHARES......................................................  29
CALCULATION OF PERFORMANCE INFORMATION....................................  31
DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES...........................  31
</TABLE>    
 
                                       2
<PAGE>
 
                              SUMMARY OF EXPENSES
           (FOR AN INSTITUTIONAL CLASS SHARE OF EACH INDICATED FUND)
   
  The following information is provided as an aid in understanding the various
expenses that an investor in a Fund will bear indirectly. The information below
is based on expenses for the Funds' most recent fiscal year, and should not be
considered a representation of past or future expenses, as actual expenses may
be greater or less than those shown. Also, the 5% annual return assumed in the
Example should not be considered a representation of investment performance, as
actual performance will vary.     
 
<TABLE>   
<CAPTION>
                                      CORE   INTERNATIONAL MID-CAP    MID-CAP
                                      VALUE     EQUITY     GROWTH      VALUE
                                      FUND       FUND       FUND       FUND
                                      -----  ------------- -------    -------
<S>                                   <C>    <C>           <C>        <C>
Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on
  Purchases (as % of offering
  price)............................  none       none       none       none
 Maximum Sales Load Imposed on
  Reinvested Dividends (as % of
  offering price)...................  none       none       none       none
 Maximum Deferred Sales Load (as %
  of original purchase price or
  redemption proceeds)..............  none       none       none       none
 Redemption Fees/1.............../..  none       none       none       none
 Exchange Fees......................  none       none       none       none
Annual Fund Operating Expenses (as a
 percentage of average net assets):
 Management Fees....................   .50%       .75%       .75%       .75%
 12b-1 Fees.........................  none       none       none       none
 Other Operating Expenses (after
  expense reimbursements where
  indicated)........................   .29%       .25%/2/    .25%/2/    .25%/2/
 Total Fund Operating Expenses
  (after expense reimbursements
  where indicated)..................   .79%      1.00%/2/   1.00%/2/   1.00%/2/
Example:
An investor would pay the following
 expenses on a $1,000 investment
 assuming a 5% annual return (with
 or without a redemption at the end
 of each time period):
 One Year...........................  $  8       $ 10       $ 10       $ 10
 Three Years........................  $ 25       $ 32       $ 32       $ 32
 Five Years.........................  $ 44       $ 55       $ 55       $ 55
 Ten Years..........................  $ 98       $122       $122       $122
</TABLE>    
 
                                       3
<PAGE>
 
<TABLE>   
<CAPTION>
                                       SMALL       SMALL   STRATEGIC
                                     CAP GROWTH  CAP VALUE   VALUE     WORLDWIDE
                                        FUND       FUND      FUND        FUND
                                     ----------  --------- ---------   ---------
<S>                                  <C>         <C>       <C>         <C>
Shareholder Transaction Expenses:
 Maximum Sales Load Imposed on
  Purchases
  (as % of offering price).........     none       none      none        none
 Maximum Sales Load Imposed on
  Reinvested Dividends (as % of
  offering price)..................     none       none      none        none
 Maximum Deferred Sales Load (as %
  of original purchase price or
  redemption proceeds).............     none       none      none        none
 Redemption Fees/1............../..     none       none      none        none
 Exchange Fees.....................     none       none      none        none
Annual Fund Operating Expenses (as
 a percentage of average net
 assets):
 Management Fees...................      .75%       .75%      .50%        .75%
 12b-1 Fees........................     none       none      none        none
 Other Operating Expenses (after
  expense reimbursements where
  indicated).......................      .25%/2/    .17%      .50%/2/     .25%/2/
 Total Fund Operating Expenses
  (after expense reimbursements
  where indicated).................     1.00%/2/    .92%     1.00%/2/    1.00%/2/
Example:
An investor would pay the following
 expenses on a $1,000 investment
 assuming a 5% annual return (with
 or without a redemption at the end
 of each time period):
 One Year..........................     $ 10       $  9      $ 10        $ 10
 Three Years.......................     $ 32       $ 29      $ 32        $ 32
 Five Years........................     $ 55       $ 51      $ 55        $ 55
 Ten Years.........................     $122       $113      $122        $122
</TABLE>    
- -----------
/1/A $5 charge applies to any wire transfer of redemption proceeds from any
   Fund.
   
/2/Loomis Sayles has voluntarily agreed, for an indefinite period, to limit
  the Funds' Total Operating Expenses to the percentages of net assets shown
  in the table. Without this agreement, Other Operating Expenses and Total
  Operating Expenses would have been 0.43% and, 1.18% respectively, for the
  International Equity Fund, 6.38% and 7.13%, respectively, for the Mid-Cap
  Growth Fund, 3.58% and 4.33% respectively, for the Mid-Cap Value Fund, 1.40%
  and 2.15%, respectively, for the Small Cap Growth Fund, 10.31% and 10.81%,
  respectively, for the Strategic Value Fund and 2.53% and 3.28%,
  respectively, for the Worldwide Fund. Other Operating Expenses and Total
  Operating Expenses for the Core Value Fund and the Small Cap Value Fund were
  unaffected by this Agreement.     
 
 
                                       4
<PAGE>
 
                             FINANCIAL HIGHLIGHTS
     (FOR AN INSTITUTIONAL CLASS SHARE OF EACH INDICATED FUND OUTSTANDING
                       THROUGHOUT THE INDICATED PERIODS)
   
  The financial highlights tables that follow have been audited by
PricewaterhouseCoopers LLP, independent accountants. The following information
should be read in conjunction with the financial highlights, financial
statements and the notes thereto contained in the Funds' 1998 Annual Report,
which is incorporated by reference in this Prospectus and the Statement of
Additional Information.     
<TABLE>   
<CAPTION>
                                                      CORE VALUE FUND
                          -----------------------------------------------------------------------------
                           NINE MONTHS                                                         MAY 13**
                              ENDED                    YEAR ENDED DEC. 31,                        TO
                          SEPTEMBER 30,* ----------------------------------------------------  DEC. 31,
                               1998       1997     1996     1995     1994     1993     1992      1991
                          -------------- -------  -------  -------  -------  -------  -------  --------
<S>                       <C>            <C>      <C>      <C>      <C>      <C>      <C>      <C>
Net asset value,
 beginning of period....     $ 17.64     $ 15.60  $ 14.57  $ 11.80  $ 12.49  $ 11.53  $ 10.54   $10.00
                             -------     -------  -------  -------  -------  -------  -------   ------
Income from investment
 operations--
 Net investment income
  (loss)................        0.18        0.18     0.22     0.23     0.15     0.13     0.13     0.12
 Net realized and
  unrealized gain (loss)
  on investments........       (0.97)       4.32     2.83     3.93    (0.26)    1.24     1.36     0.59
                             -------     -------  -------  -------  -------  -------  -------   ------
 Total from investment
  operations............       (0.79)       4.50     3.05     4.16    (0.11)    1.37     1.49     0.71
                             -------     -------  -------  -------  -------  -------  -------   ------
 Less distributions--
 Dividends from net
  investment income.....        0.00       (0.19)   (0.22)   (0.23)   (0.15)   (0.12)   (0.13)   (0.12)
 Distributions from net
  realized capital
  gains.................        0.00       (2.27)   (1.80)   (1.16)   (0.43)   (0.29)   (0.37)   (0.05)
                             -------     -------  -------  -------  -------  -------  -------   ------
 Total distributions....        0.00       (2.46)   (2.02)   (1.39)   (0.58)   (0.41)   (0.50)   (0.17)
                             -------     -------  -------  -------  -------  -------  -------   ------
Net asset value, end of
 period.................     $ 16.85     $ 17.64  $ 15.60  $ 14.57  $ 11.80  $ 12.49  $ 11.53   $10.54
                             =======     =======  =======  =======  =======  =======  =======   ======
Total return (%)***.....        (4.5)++     29.2     21.2     35.2     (0.9)    11.9     14.1      7.2
Net assets, end of
 period (000)...........     $66,928     $63,303  $43,715  $36,465  $25,946  $20,657  $12,279   $7,689
Ratio of operating
 expenses to average net
 assets (%)****.........        0.79+       0.84     1.13     1.20     1.33     1.50     1.50     1.50+
Ratio of net investment
 income to average net
 assets (%).............        1.36+       1.12     1.44     1.61     1.28     1.23     1.42     2.09+
Portfolio turnover rate
 (%)....................          49++        64       58       60       48       53       67       27
Without giving effect to
 voluntary expense
 limitations:
 The ratios of operating
  expenses to average
  net assets would have
  been (%)..............        0.79+       0.84     1.13     1.20     1.33     1.56     2.19     2.59+
 Net investment income
  per share would have
  been..................     $  0.18     $  0.18  $  0.22  $  0.23  $  0.15  $  0.12  $  0.07   $ 0.06
</TABLE>    
- -----------
   
   *The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   
   + Computed on an annualized basis.     
    
  ++ Periods less than one year are not annualized.     
       

                                       5
<PAGE>
 
<TABLE>   
<CAPTION>
                                                 INTERNATIONAL EQUITY FUND
                          -----------------------------------------------------------------------------
                           NINE MONTHS                                                         MAY 10**
                              ENDED                    YEAR ENDED DEC. 31,                        TO
                          SEPTEMBER 30*, ----------------------------------------------------  DEC. 31,
                               1998       1997     1996     1995     1994     1993     1992      1991
                          -------------- -------  -------  -------  -------  -------  -------  --------
<S>                       <C>            <C>      <C>      <C>      <C>      <C>      <C>      <C>
Net asset value,
 beginning of period....     $ 11.30     $ 13.16  $ 11.65  $ 11.61  $ 12.90  $  9.64  $ 10.27   $10.00
                             -------     -------  -------  -------  -------  -------  -------   ------
Income from investment
 operations--
Net investment income
 (loss).................        0.14        0.15+    0.12     0.14     0.15     0.11     0.10     0.08
Net realized and
 unrealized gain (loss)
 on investments.........       (0.70)      (0.27)    2.01     0.87    (0.38)    3.61    (0.62)    0.29
                             -------     -------  -------  -------  -------  -------  -------   ------
 Total from investment
  operations............       (0.56)      (0.12)    2.13     1.01    (0.23)    3.72    (0.52)    0.37
                             -------     -------  -------  -------  -------  -------  -------   ------
Less distributions--
 Dividends from net
  investment income.....        0.00       (0.19)   (0.09)   (0.14)   (0.14)   (0.10)   (0.10)   (0.08)
 Distributions from net
  realized capital
  gains.................        0.00       (1.55)   (0.53)   (0.83)   (0.92)   (0.36)   (0.01)    0.00
 Distributions from
  capital...............        0.00        0.00     0.00     0.00     0.00     0.00     0.00    (0.02)
                             -------     -------  -------  -------  -------  -------  -------   ------
 Total distributions....        0.00       (1.74)   (0.62)   (0.97)   (1.06)   (0.46)   (0.11)   (0.10)
                             -------     -------  -------  -------  -------  -------  -------   ------
 Net asset value, end of
  period................     $ 10.74     $ 11.30  $ 13.16  $ 11.65  $ 11.61  $ 12.90  $  9.64   $10.27
                             =======     =======  =======  =======  =======  =======  =======   ======
Total return (%)***.....        (5.0)+++    (1.0)    18.3      8.7     (1.8)    38.5     (5.1)     3.7
Net assets, end of
 period (000)...........     $68,464     $82,188  $90,662  $79,488  $73,189  $56,560  $14,937   $6,916
Ratio of operating
 expenses to average net
 assets (%)****.........        1.00++      1.00     1.42     1.45     1.46     1.50     1.50     1.50++
Ratio of net investment
 income to average net
 assets (%).............        1.49++      1.12     0.96     1.16     1.30     1.20     1.64     1.55++
Portfolio turnover
 rate (%)...............          96+++      119      151      133      116      128      101      109
Without giving effect to
 voluntary expense
 limitations:
 The ratios of operating
  expenses to average
  net assets would have
  been (%)..............        1.18++      1.16     1.42     1.45     1.46     1.72     2.77     3.66++
 Net investment income
  per share would have
  been..................     $  0.12     $  0.13+ $  0.12  $  0.14  $  0.15  $  0.09  $  0.02   $(0.03)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.
  ++ Computed on an annualized basis.
    
 +++ Periods less than one year are not annualized.     
       
                                       6
<PAGE>
 
<TABLE>   
<CAPTION>
                                                           MID-CAP GROWTH FUND
                                                         -----------------------
                                                          NONE MONTHS   JAN 2**
                                                             ENDED         TO
                                                         SEPTEMBER 30*, DEC. 31,
                                                              1998        1997
                                                         -------------- --------
<S>                                                      <C>            <C>
Net asset value, beginning of period...................      $11.49      $10.00
                                                             ------      ------
Income from investment operations--
Net investment income (loss)...........................       (0.03)      (0.03)
Net realized and unrealized gain (loss) on
 investments...........................................       (0.95)       2.26
                                                             ------      ------
 Total from investment operations......................       (0.98)       2.23
                                                             ------      ------
Less distributions--
 Distributions in excess of net investment income......        0.00       (0.12)
 Distributions from net realized capital gains.........        0.00       (0.62)
                                                             ------      ------
 Total distributions...................................        0.00       (0.74)
                                                             ------      ------
 Net asset value, end of period........................      $10.51      $11.49
                                                             ======      ======
Total return (%)***....................................        (8.5)++     22.7
Net assets, end of period (000)........................      $2,073      $1,848
Ratio of operating expenses to average net assets
 (%)****...............................................        1.00+       1.00+
Ratio of net investment income to average net assets
 (%)...................................................       (0.35)+    (0.38)+
Portfolio turnover rate (%)............................          82++       174
Without giving effect to voluntary expense limitations:
 The ratios of operating expenses to average net assets
  would have been (%)..................................        7.13+       9.35+
 Net investment income per share would have been.......      $(0.50)     $(0.60)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
    
  ++ Periods less than one year are not annualized.     

       
                                       7
<PAGE>
 
<TABLE>   
<CAPTION>
                                                          MID-CAP VALUE FUND
                                                      --------------------------
                                                       NINE MONTHS
                                                          ENDED      JAN. 2** TO
                                                      SEPTEMBER 30*,  DEC. 31,
                                                           1998         1997
                                                      -------------- -----------
<S>                                                   <C>            <C>
Net asset value, beginning of period................      $11.53       $10.00
                                                          ------       ------
Income from investment operations--
Net investment income (loss)........................        0.02         0.07
Net realized and unrealized gain (loss) on
 investments........................................       (1.46)        2.54
                                                          ------       ------
 Total from investment operations...................       (1.44)        2.61
                                                          ------       ------
Less distributions--
 Dividends from net investment income...............        0.00        (0.14)
 Distributions from net realized capital gains......        0.00        (0.94)
                                                          ------       ------
 Total distributions................................        0.00        (1.08)
                                                          ------       ------
 Net asset value, end of period.....................      $10.09       $11.53
                                                          ======       ======
Total return (%)***.................................       (12.5)++      26.3
Net assets, end of period (000).....................      $3,291       $3,736
Ratio of operating expenses to average net assets
 (%)****............................................        1.00+        1.00+
Ratio of net investment income to average net assets
 (%)................................................        0.22+        0.74+
Portfolio turnover rate (%).........................         225++        130
Without giving effect to voluntary expense
 limitations:
 The ratios of operating expenses to average net
  assets would have been (%)........................        4.33+        6.65+
 Net investment income per share would have been....      $(0.29)      $(0.49)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
    
  ++ Periods less than one year are not annualized.     
       

                                       8
<PAGE>
 
<TABLE>   
<CAPTION>
                                                       SMALL CAP GROWTH FUND
                                                      -----------------------
                                                       NINE MONTHS   JAN. 2**
                                                          ENDED         TO
                                                      SEPTEMBER 30*, DEC. 31,
                                                           1998        1997
                                                      -------------- --------
<S>                                                   <C>            <C>
Net asset value, beginning of period................     $ 11.32      $10.00
                                                         -------      ------
Income from investment operations--
Net investment income (loss)........................       (0.02)      (0.07)***
Net realized and unrealized gain (loss) on
 investments........................................       (1.47)       1.99
                                                         -------      ------
 Total from investment operations...................       (1.49)       1.92
                                                         -------      ------
Less distributions--
 Distributions in excess of net investment income...        0.00       (0.01)
 Distributions in excess of net realized capital
  gains.............................................        0.00       (0.59)
                                                         -------      ------
 Total distributions................................        0.00       (0.60)
                                                         -------      ------
 Net asset value, end of period.....................     $  9.83      $11.32
                                                         =======      ======
Total return (%)****................................       (13.2)+++    19.4
Net assets, end of period (000).....................     $17,174      $3,893
Ratio of operating expenses to average net assets
 (%)+...............................................        1.00++      1.00++
Ratio of net investment income to average net assets
 (%)................................................       (0.53)++    (0.65)++
Portfolio turnover rate (%).........................         116+++      211
Without giving effect to voluntary expense
 limitations:
 The ratios of operating expenses to average net
  assets would have been (%)........................        2.15++      5.81++
 Net investment income per share would have been....     $ (0.07)     $(0.56)***
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   + The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.
  ++ Computed on an annualized basis.
    
 +++ Periods less than one year are not annualized.     
       

                                       9
<PAGE>
 
<TABLE>   
<CAPTION>
                                                    SMALL CAP VALUE FUND
                          -------------------------------------------------------------------------------
                           NINE MONTHS                                                           MAY 13**
                              ENDED                     YEAR ENDED DEC. 31,                         TO
                          SEPTEMBER 30*, ------------------------------------------------------  DEC. 31,
                               1998        1997      1996     1995     1994     1993     1992      1991
                          -------------- --------  --------  -------  -------  -------  -------  --------
<S>                       <C>            <C>       <C>       <C>      <C>      <C>      <C>      <C>
Net asset value,
 beginning of period....     $  18.62    $  17.39  $  15.33  $ 12.86  $ 14.13  $ 12.88  $ 12.49  $ 10.00
                             --------    --------  --------  -------  -------  -------  -------  -------
Income from investment
 operations--
 Net investment income
  (loss)................         0.12        0.17      0.11     0.04    (0.04)    0.00    (0.06)   (0.01)
 Net realized and
  unrealized gain (loss)
  on investments........        (3.14)       4.26      4.47     4.06    (1.12)    3.15     1.67     3.03
                             --------    --------  --------  -------  -------  -------  -------  -------
 Total from investment
  operations............        (3.02)       4.43      4.58     4.10    (1.16)    3.15     1.61     3.02
                             --------    --------  --------  -------  -------  -------  -------  -------
Less distributions--
 Dividends from net
  investment income.....         0.00       (0.15)    (0.11)   (0.04)    0.00     0.00     0.00     0.00
 Distributions from net
  realized capital
  gains.................         0.00       (3.05)    (2.41)   (1.59)   (0.11)   (1.90)   (1.22)   (0.53)
                             --------    --------  --------  -------  -------  -------  -------  -------
 Total distributions....         0.00       (3.20)    (2.52)   (1.63)   (0.11)   (1.90)   (1.22)   (0.53)
                             --------    --------  --------  -------  -------  -------  -------  -------
Net asset value, end of
 period.................     $  15.60    $  18.62  $  17.39  $ 15.33  $ 12.86  $ 14.13  $ 12.88  $ 12.49
                             ========    ========  ========  =======  =======  =======  =======  =======
Total return (%)***.....        (16.2)++     26.0      30.4     32.1     (8.2)    24.7     13.1     30.5
Net assets, end of
 period (000)...........     $296,116    $245,177  $163,625  $90,455  $73,126  $67,553  $39,244  $14,581
Ratio of operating
 expenses to average net
 assets (%)****.........         0.92+       0.94      1.19     1.25     1.27     1.35     1.50     1.50+
Ratio of net investment
 income to average net
 assets (%).............         1.04+       0.97      0.80     0.29    (0.30)   (0.38)   (0.79)   (0.19)+
Portfolio turnover rate
 (%)....................           78++        94        73      155       87      106      109       56
Without giving effect to
 voluntary expense
 limitations:
 The ratios of operating
  expenses to average
  net assets would have
  been (%)..............         0.92+       0.94      1.19     1.25     1.27     1.35     1.66     2.43+
 Net investment income
  per share would have
  been..................     $   0.12    $   0.17  $   0.11  $  0.04  $ (0.04) $  0.00  $ (0.07) $ (0.06)
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
    
  ++ Periods less than one year are not annualized.     
       

                                       10
<PAGE>
 
<TABLE>   
<CAPTION>
                                                       STRATEGIC VALUE FUND
                                                     -------------------------
                                                      NINE MONTHS     JAN. 2**
                                                         ENDED           TO
                                                     SEPTEMBER 30*,   DEC. 31,
                                                          1998          1997
                                                     --------------   --------
<S>                                                  <C>              <C>           
Net asset value, beginning of period...............      $11.76       $ 10.00       
                                                         ------       -------       
Income from investment operations--                                                 
 Net investment income (loss)......................       (0.02)        (0.01)***   
 Net realized and unrealized gain (loss) on                                         
  investments......................................       (1.27)         1.98       
                                                         ------       -------       
 Total from investment operations..................       (1.29)         1.97       
                                                         ------       -------       
Less distributions--                                                                
 Distributions in excess of net investment income..        0.00         (0.21)      
                                                         ------       -------       
 Total distributions...............................        0.00         (0.21)      
                                                         ------       -------       
Net asset value, end of period.....................      $10.47       $ 11.76       
                                                         ======       =======       
Total return (%)****...............................       (11.0)+++      19.7       
Net assets, end of period (000)....................      $  932          $965       
Ratio of operating expenses to average net assets                                   
 (%)+..............................................        1.00++        1.00++     
Ratio of net investment income to average net                                       
 assets (%)........................................       (0.22)++      (0.05)++    
Portfolio turnover rate (%)........................          31+++         34       
Without giving effect to voluntary expense                                          
 limitations:                                                                       
 The ratios of operating expenses to average net                                    
  assets would have                                                                 
  been (%).........................................       10.81++       16.55++     
 Net investment income per share would have been...      $(0.97)      $ (1.76)***    
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Per share net investment income has been determined on the basis of the
     weighted average number of shares outstanding during the period.     
   
**** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   + The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.
  ++ Computed on an annualized basis.
    
 +++ Periods less than one year are not annualized.     
       

                                      11
<PAGE>
 
<TABLE>   
<CAPTION>
                                                        WORLDWIDE FUND
                                               --------------------------------
                                                NINE MONTHS     YEAR   MAY 1**
                                                   ENDED       ENDED      TO
                                               SEPTEMBER 30*, DEC. 31, DEC. 31,
                                                    1998        1997     1996
                                               -------------- -------- --------
<S>                                            <C>            <C>      <C>
Net asset value, beginning of period.........       $9.86      $10.63  $ 10.00
                                                   ------      ------  -------
Income from investment operations--
 Net investment income (loss)................        0.33        0.47     0.30
 Net realized and unrealized gain (loss) on
  investments................................       (1.40)      (0.10)    0.63
                                                   ------      ------  -------
 Total from investment operations............       (1.07)       0.37     0.93
                                                   ------      ------  -------
Less distributions--
 Dividends from net investment income........        0.00       (0.47)   (0.30)
 Distributions from net realized capital
  gains......................................        0.00       (0.67)    0.00
                                                   ------      ------  -------
 Total distributions.........................        0.00       (1.14)   (0.30)
                                                   ------      ------  -------
Net asset value, end of period...............      $ 8.79      $ 9.86  $ 10.63
                                                   ======      ======  =======
Total return (%)***..........................       (10.9)++      3.5      9.2
Net assets, end of period (000)..............      $4,907      $5,597  $ 5,189
Ratio of operating expenses to average net
 assets (%)****..............................        1.00+       1.00     1.00+
Ratio of net investment income to average net
 assets (%)..................................        4.37+       3.89     4.62+
Portfolio turnover rate (%)..................          93++       134       76
Without giving effect to voluntary expense
 limitations:
 The ratios of operating expenses to average
  net assets would have been (%).............        3.28+       2.62     3.72+
 Net investment income per share would have
  been.......................................      $ 0.16      $ 0.27  $  0.13
</TABLE>    
- -----------
   
   * The Fund's fiscal year-end changed to September 30 from December 31.     
   
  ** Commencement of investment operations.     
   
 *** Total returns would have been lower had the adviser not reduced its
     advisory fee and/or borne other operating expenses.     
   
**** The adviser has agreed to reimburse a portion of the Fund's expenses
     during the period. Without this reimbursement, the Fund's ratio of
     operating expenses would have been higher.     
   + Computed on an annualized basis.
    
  ++ Periods less than one year are not annualized.     
       
NOTE: Further information about each Fund's performance is contained in the
      Funds' annual report to shareholders, which may be obtained without
      charge.
 
                                      12
<PAGE>
 
                                   THE TRUST
 
  Each Fund is a series of Loomis Sayles Funds (the "Trust"). The Trust is a
diversified open-end management investment company organized as a
Massachusetts business trust on February 20, 1991. The Trust is authorized to
issue an unlimited number of full and fractional shares of beneficial interest
in multiple series. Shares are freely transferable and entitle shareholders to
receive dividends as determined by the Trust's board of trustees and to cast a
vote for each share held at shareholder meetings. The Trust does not generally
hold shareholder meetings and will do so only when required by law.
Shareholders may call meetings to consider removal of the Trust's trustees.
 
                      INVESTMENT OBJECTIVES AND POLICIES
 
LOOMIS SAYLES CORE VALUE FUND
 
  The Fund's investment objective is long-term growth of capital and income.
   
  The Fund seeks to achieve its objective by investing substantially all of
its assets in common stocks or their equivalent that Loomis Sayles considers
to be undervalued in relation to the issuer's earnings, dividends, assets and
growth prospects. The Fund may invest up to 20% of its total assets in
securities of foreign issuers. The Fund may also engage in foreign currency
hedging transactions, real estate investment trusts ("REITs") and Rule 144A
securities.     
       
LOOMIS SAYLES INTERNATIONAL EQUITY FUND
 
  The Fund's investment objective is high total investment return through a
combination of capital appreciation and current income.
   
  The Fund seeks to achieve its objective by investing primarily in equity
securities of companies organized or headquartered outside the United States.
Under normal conditions the Fund will invest at least 65% of its total assets
in equity securities of issuers from at least three countries outside the
United States. For temporary defensive purposes, the Fund may invest as much
as 100% of its total assets in issuers from one or two countries, which may
include the United States. The Fund may also engage in foreign currency
hedging transactions, options transactions, REITs and Rule 144A securities.
    
LOOMIS SAYLES MID-CAP GROWTH FUND
 
  The Fund's investment objective is long-term capital growth from investments
in common stocks or their equivalent.
 
 
                                      13
<PAGE>
 
   
  The Fund seeks to achieve its objective by investing, under normal market
conditions, at least 65% of its total assets in equity securities of companies
with a market capitalization that falls within the capitalization range of
companies included in the Standard & Poor's Mid-Cap 400 Index. Current income
is not a consideration in selecting the Fund's investments. The Fund may
invest any portion of its assets in securities of Canadian issuers and up to
20% of its total assets in the securities of issuers headquartered outside the
United States or Canada. The Fund may also engage in foreign currency hedging
transactions, options and futures transactions, securities lending, and Rule
144A securities.     
 
LOOMIS SAYLES MID-CAP VALUE FUND
 
  The Fund's objective is long-term capital growth from investments in common
stocks or their equivalent.
   
  The Fund seeks to achieve its objective by investing, under normal market
conditions, at least 65% of its total assets in equity securities of companies
with a market capitalization that falls within the capitalization range of
companies included in the Standard & Poor's Mid-Cap 400 Index. Loomis Sayles
seeks to build a core portfolio of equity securities that it believes to be
undervalued by the market in relation to the issuers' earnings, dividends,
assets and growth prospects and that has a smaller emphasis on special
situations and turnarounds (companies that have experienced significant
business problems but that Loomis Sayles believes have favorable prospects for
recovery). Current income is not a consideration in selecting the Fund's
investments. The Fund may invest any portion of its assets in securities of
Canadian issuers and up to 20% of its total assets in the securities of
issuers headquartered outside the United States or Canada. The Fund may also
engage in foreign currency hedging transactions, options and futures
transactions, securities lending, REITs and Rule 144A securities.     
 
LOOMIS SAYLES SMALL CAP GROWTH FUND
 
  The Fund's investment objective is long-term capital growth from investments
in common stocks or their equivalent.
   
  The Fund seeks to achieve its objective by investing primarily in equity
securities of small, rapidly growing companies that Loomis Sayles believes
have the potential for accelerating earnings growth and rising profit margins.
The Fund will normally invest at least 65% of its total assets in equity
securities of companies with market capitalizations that fall within the
capitalization range of the Russell 2000 Index and may invest up to 35% of its
total assets in larger companies. Loomis Sayles seeks companies that have
distinctive products, technologies, or services; dynamic earnings growth;
prospects for a high level of profitability; and outstanding management.
Current income is not a consideration in selecting the Fund's investments. The
Fund may invest any     
 
                                      14
<PAGE>
 
   
portion of its assets in securities of Canadian issuers and up to 20% of its
total assets in the securities of issuers headquartered outside the United
States or Canada. The Fund may also engage in foreign currency hedging
transactions, options and futures transactions, securities lending, and Rule
144A securities.     
 
LOOMIS SAYLES SMALL CAP VALUE FUND
 
  The Fund's investment objective is long-term capital growth from investments
in common stocks or their equivalent.
   
  The Fund seeks to achieve its objective by investing primarily in equity
securities of small capitalization companies with good earnings growth
potential that Loomis Sayles believes are undervalued by the market. The Fund
will normally invest at least 65% of its total assets in equity securities of
companies with market capitalizations that fall within the capitalization
range of the Russell 2000 Index and may invest up to 35% of its total assets
in larger companies. Loomis Sayles seeks to build a core small capitalization
portfolio of stocks of solid companies with reasonable growth prospects and
that are attractively priced in relation to the companies' earnings with a
smaller emphasis on special situations and turnarounds (companies that have
experienced significant business problems but which Loomis Sayles believes
have favorable prospects for recovery), as well as unrecognized stocks.
Current income is not a consideration in selecting the Fund's investments. The
Fund may invest up to 20% of its total assets in securities of foreign
issuers. The Fund may also engage in foreign currency hedging transactions,
REITs and Rule 144A securities.     
 
 
LOOMIS SAYLES STRATEGIC VALUE FUND
 
  The Fund's investment objective is long-term capital growth from investments
in common stocks or their equivalent.
   
  The Fund seeks to achieve its objective by investing substantially all of
its assets in equity securities that Loomis Sayles considers to be undervalued
by the markets. Stocks are selected based on a combination of quantitative
factors including historical, relative price-earnings ratios; price-earnings
ratios relative to growth rates; relative fundamentals and price movement; and
qualitative factors including the quality of management, position in the
industry, debt and balance sheet restructuring and product cycles. The Fund's
strategy is to have a relatively concentrated portfolio normally consisting of
approximately 35-40 securities that Loomis Sayles considers best positioned to
perform in the current and future environments. The Fund may invest any
portion of its assets in the securities of Canadian issuers and up to 20% of
its total assets in securities of issuers headquartered outside the United
States or Canada. The Fund may also engage in foreign currency hedging
transactions, options and futures transactions, securities lending, REITs and
Rule 144A securities.     
 
                                      15
<PAGE>
 
LOOMIS SAYLES WORLDWIDE FUND
 
  The Fund's investment objective is high total investment return through a
combination of capital appreciation and current income.
   
  The Fund seeks to achieve its objective by investing in U.S. and foreign
equity and debt securities. The allocation of the Fund's assets among the four
sectors of domestic equities, international equities, domestic bonds and
international bonds will be made by Loomis Sayles' Global Asset Allocation
group. The Fund will normally invest its assets in securities of issuers from
at least three countries, one of which may be the United States. The Fund may
also invest in collateralized mortgage obligations, zero coupon securities,
when-issued securities, REITs and Rule 144A securities. The Fund may engage in
foreign currency hedging transactions and options and forward contract
transactions.     
 
ALL FUNDS
   
  For temporary defensive purposes, each Fund may invest any portion of its
assets in fixed income securities, cash and any other securities deemed
appropriate by Loomis Sayles. Except for each Fund's investment objective, and
any investment policies that are identified as "fundamental," all of the
investment policies of each Fund may be changed without a vote of Fund
shareholders.     
 
     MORE INFORMATION ABOUT THE FUNDS' INVESTMENTS AND RISK CONSIDERATIONS
 
COMMON STOCKS AND OTHER EQUITY SECURITIES
 
  Common stocks and similar equity securities, such as warrants and
convertibles, are volatile and more risky than some other forms of investment.
The value of an investment in a Fund that invests in equity securities may
sometimes decrease. Equity securities of companies with relatively small
market capitalization may be more volatile than the securities of larger, more
established companies and than the broad equity market indexes.
 
DEBT AND OTHER FIXED INCOME SECURITIES
 
  The Worldwide Fund may invest in fixed income securities of any maturity.
Fixed income securities pay a specified rate of interest or dividends, or a
rate that is adjusted periodically by reference to some specified index or
market rate. Fixed income securities include securities issued by federal,
state, local and foreign governments and related agencies, and by a wide range
of private issuers. Because interest rates vary, it is impossible to predict
the yield of a Fund
 
                                      16
<PAGE>
 
that invests in fixed income securities for any particular period. The net
asset value of such a Fund's shares will vary as a result of changes in the
value of the securities in the Fund's portfolio.
 
  Fixed income securities are subject to market and credit risk. Market risk
relates to changes in a security's value as a result of changes in interest
rates generally. In general, the values of fixed income securities increase
when prevailing interest rates fall and decrease when interest rates rise.
Credit risk relates to the ability of the issuer to make payments of principal
and interest.
 
ZERO COUPON SECURITIES
 
  The Worldwide Fund may invest in "zero coupon" fixed income securities.
These securities accrue interest at a specified rate, but do not pay interest
in cash on a current basis. A Fund investing in zero coupon securities is
required to distribute the income on these securities to Fund shareholders as
the income accrues, even though the Fund is not receiving the income in cash
on a current basis. Thus the Fund may have to sell other investments to obtain
cash to make income distributions. The market value of zero coupon securities
is often more volatile than that of non-zero coupon fixed income securities of
comparable quality and maturity.
 
COLLATERALIZED MORTGAGE OBLIGATIONS
 
  The Worldwide Fund may invest in collateralized mortgage obligations
("CMOs"). A CMO is a security backed by a portfolio of mortgages or mortgage-
backed securities held under an indenture. CMOs may be issued either by U.S.
Government instrumentalities or by non-governmental entities. The issuer's
obligation to make interest and principal payments is secured by the
underlying portfolio of mortgages or mortgage-backed securities. CMOs are
issued with a number of classes or series which have different maturities and
which may represent interests in some or all of the interest or principal
payments on the underlying collateral or a combination thereof. CMOs of
different classes are generally retired in sequence as the underlying mortgage
loans in the mortgage pool are repaid. In the event of sufficient early
prepayments on such mortgages, the class or series of CMOs first to mature
generally will be retired prior to its maturity. As with other mortgage-backed
securities, the early retirement of a particular class or series of CMOs held
by a Fund could involve the loss of any premium the Fund paid when it acquired
the investment and could result in the Fund's reinvesting the proceeds at a
lower interest rate than the retired CMO paid. Because of the early retirement
feature, CMOs may be more volatile than many other fixed-income investments.
 
WHEN-ISSUED SECURITIES
 
  Each Fund may purchase securities on a "when-issued" basis. This means that
the Fund will enter into a commitment to buy the security before the
 
                                      17
<PAGE>
 
security has been issued. The Fund's payment obligation and the interest rate
on the security are determined when the Fund enters into the commitment. The
security is typically delivered to the Fund 15 to 120 days later. No interest
accrues on the security between the time the Fund enters into the commitment
and the time the security is delivered. If the value of the security being
purchased falls between the time a Fund commits to buy it and the payment
date, the Fund may sustain a loss. The risk of this loss is in addition to the
Fund's risk of loss on the securities actually in its portfolio at the time.
In addition, when the Fund buys a security on a when-issued basis, it is
subject to the risk that market rates of interest will increase before the
time the security is delivered, with the result that the yield on the security
delivered to the Fund may be lower than the yield available on other,
comparable securities at the time of delivery. If a Fund has outstanding
obligations to buy when-issued securities, it will maintain liquid assets in a
segregated account at its custodian bank in an amount sufficient to satisfy
these obligations.
   
REAL ESTATE INVESTMENT TRUSTS     
   
  The Funds may invest in REITs. REITs involve certain unique risks in
addition to those risks associated with investing in the real estate industry
in general (such as possible declines in the value of real estate, lack of
availability of mortgage funds or extended vacancies of property). Equity
REITs may be affected by changes in the value of the underlying property owned
by the REITs, while mortgage REITs may be affected by the quality of any
credit extended. REITs are dependent upon management skills, are not
diversified, are subject to heavy cash flow dependency, risks of default by
borrowers and self-liquidation. REITs are also subject to the possibilities of
failing to qualify for tax-free pass-through of income under the Code, and
failing to maintain their exemptions from registration under the Investment
Company Act of 1940 (the "1940 Act").     
   
  Investment in REITs involves risk similar to those associated with investing
in small capitalization companies. REITs may have limited financial resources,
may trade less frequently and in a limited volume and may be subject to more
abrupt or erratic price movements than larger securities.     
 
RULE 144A SECURITIES
 
  Each Fund may invest in Rule 144A securities, which are privately offered
securities that can be resold only to certain qualified institutional buyers.
Rule 144A securities are treated as illiquid, unless Loomis Sayles has
determined, under guidelines established by the Trust's trustees, that the
particular issue of Rule 144A securities is liquid.
 
                                      18
<PAGE>
 
FOREIGN SECURITIES
   
  Each Fund may invest in securities of issuers organized or headquartered
outside the United States ("foreign securities"). Each of the Core Value and
Small Cap Value Funds will not purchase a foreign security if, as a result,
the Fund's holdings of foreign securities would exceed 20% of the Fund's total
assets. Each of the Mid-Cap Growth, Mid-Cap Value, Small Cap Growth and
Strategic Value Funds may each invest any portion of its assets in securities
of Canadian issuers, but will not purchase foreign securities other than those
of Canadian issuers if, as a result, such Fund's holding of non-U.S. and non-
Canadian securities would exceed 20% of the Fund's total assets.     
 
  Although investing in foreign securities may increase a Fund's
diversification and reduce portfolio volatility, foreign securities may
present risks not associated with investments in comparable securities of U.S.
issuers. There may be less information publicly available about a foreign
corporate or governmental issuer than about a U.S. issuer, and foreign
corporate issuers are not generally subject to accounting, auditing and
financial reporting standards and practices comparable to those in the United
States. The securities of some foreign issuers are less liquid and at times
more volatile than securities of comparable U.S. issuers. Foreign brokerage
commissions and securities custody costs are often higher than in the United
States. With respect to certain foreign countries, there is a possibility of
governmental expropriation of assets, confiscatory taxation, political or
financial instability and diplomatic developments that could affect the value
of investments in those countries. A Fund's receipt of interest on foreign
government securities may depend on the availability of tax or other revenues
to satisfy the issuer's obligations.
 
  A Fund's investments in foreign securities may include investments in
countries whose economies or securities markets are not yet highly developed.
Special considerations associated with these investments (in addition to the
considerations regarding foreign investments generally) may include, among
others, greater political uncertainties, an economy's dependence on revenues
from particular commodities or on international aid or development assistance,
currency transfer restrictions, highly limited numbers of potential buyers for
such securities and delays and disruptions in securities settlement
procedures.
 
  Since most foreign securities are denominated in foreign currencies or
traded primarily in securities markets in which settlements are made in
foreign currencies, the value of these investments and the net investment
income available for distribution to shareholders of a Fund investing in these
securities may be affected favorably or unfavorably by changes in currency
exchange rates, exchange control regulations or foreign withholding taxes.
Changes in the value relative to the U.S. dollar of a foreign currency in
which a Fund's holdings are denominated will result in a change in the U.S.
dollar value of the Fund's assets and the Fund's income available for
distribution.
 
                                      19
<PAGE>
 
  In addition, although part of a Fund's income may be received or realized in
foreign currencies, the Fund will be required to compute and distribute its
income in U.S. dollars. Therefore, if the value of a currency relative to the
U.S. dollar declines after the Fund's income has been earned in that currency,
translated into U.S. dollars and declared as a dividend, but before payment of
the dividend, the Fund could be required to liquidate portfolio securities to
pay the dividend. Similarly, if the value of a currency relative to the U.S.
dollar declines between the time the Fund accrues expenses in U.S. dollars and
the time such expenses are paid, the amount of such currency required to be
converted into U.S. dollars will be greater than the equivalent amount in such
currency of such expenses at the time they were incurred.
 
  In determining whether to invest assets of a Fund in securities of a
particular foreign issuer, Loomis Sayles will consider the likely effects of
foreign taxes on the net yield available to the Fund and its shareholders.
Compliance with foreign tax law may reduce a Fund's net income available for
distribution to shareholders.
 
FOREIGN CURRENCY HEDGING TRANSACTIONS
 
  Each Fund that invests in foreign securities may engage in foreign currency
exchange transactions, in connection with the purchase and sale of foreign
securities, to protect the value of specific portfolio positions or in
anticipation of changes in relative values of currencies in which current or
future Fund portfolio holdings are denominated or quoted. For example, to
protect against a change in the foreign currency exchange rate between the
date on which a Fund contracts to purchase or sell a security and the
settlement date for the purchase or sale, or to "lock in" the equivalent of a
dividend or interest payment in another currency, a Fund might purchase or
sell a foreign currency on a spot (that is, cash) basis at the prevailing spot
rate. If conditions warrant, the Funds may also enter into private contracts
to purchase or sell foreign currencies at a future date ("forward contracts").
The Funds might also purchase exchange-listed and over-the-counter call and
put options on foreign currencies. Over-the-counter currency options are
generally less liquid than exchange-listed options, and will be treated as
illiquid assets. The Funds may not be able to dispose of over-the-counter
options readily.
 
  Foreign currency transactions involve costs and may result in losses.
 
OPTIONS AND FUTURES TRANSACTIONS
 
  The International Equity, Mid-Cap Growth, Mid-Cap Value, Small Cap Growth,
Strategic Value and Worldwide Funds may buy, sell or write options on
securities, securities indexes, currencies or futures contracts. The Mid-Cap
Growth, Mid-Cap Value, Small Cap Growth and Strategic Value Funds may buy and
sell futures contracts on securities, securities indexes or currencies. Each
of
 
                                      20
<PAGE>
 
these Funds may engage in these transactions either for the purpose of
enhancing investment return, or to hedge against changes in the value of other
assets that the Fund owns or intends to acquire. Options and futures fall into
the broad category of financial instruments known as "derivatives" and involve
special risks. Use of options or futures for other than hedging purposes may
be considered a speculative activity, involving greater risks than are
involved in hedging.
 
  Options can generally be classified as either "call" or "put" options. There
are two parties to a typical options transaction: the "writer" and the
"buyer." A call option gives the buyer the right to buy a security or other
asset (such as an amount of currency or a futures contract) from, and a put
option gives the buyer the right to sell a security or other asset to, the
option writer at a specified price, on or before a specified date. The buyer
of an option pays a premium when purchasing the option, which reduces the
return on the underlying security or other asset if the option is exercised,
and results in a loss if the option expires unexercised. The writer of an
option receives a premium from writing an option, which may increase its
return if the option expires or is closed out at a profit. If a Fund as the
writer of an option is unable to close out an unexpired option, it must
continue to hold the underlying security or other asset until the option
expires, to "cover" its obligation under the option.
 
  A futures contract creates an obligation by the seller to deliver and the
buyer to take delivery of the type of instrument or cash at the time and in
the amount specified in the contract. Although many futures contracts call for
the delivery (or acceptance) of the specified instrument, futures are usually
closed out before the settlement date through the purchase (or sale) of a
comparable contract. If the price of the sale of the futures contract by a
Fund exceeds (or is less than) the price of the offsetting purchase, the Fund
will realize a gain (or loss). The value of options purchased or written by a
Fund and futures contracts held by a Fund may fluctuate based on a variety of
market and economic factors. In some cases, the fluctuations may offset (or be
offset by) changes in the value of securities held in a Fund's portfolio. All
transactions in options and futures involve the possible risk of loss to a
Fund of all or a significant part of the value of its investment. In some
cases, the risk of loss may exceed the amount of the Fund's investment. When a
Fund writes a call option or sells a futures contract without holding the
underlying securities, currencies or futures contracts, its potential loss is
unlimited. A Fund will be required, however, to set aside with its custodian
bank liquid assets in amounts sufficient at all times to satisfy its
obligations under options and futures contracts.
 
  The successful use of options and futures will usually depend on Loomis
Sayles' ability to forecast stock market, currency or other financial market
movements correctly. A Fund's ability to hedge against adverse changes in the
 
                                      21
<PAGE>
 
value of securities held in its portfolio through options and futures also
depends on the degree of correlation between the changes in the value of
futures or options positions and changes in the values of the portfolio
securities. The successful use of futures and exchange traded options also
depends on the availability of a liquid secondary market to enable a Fund to
close its positions on a timely basis. There can be no assurance that such a
market will exist at any particular time. In the case of options that are not
traded on an exchange ("over-the-counter" options), a Fund is at risk that the
other party to the transaction will default on its obligations, or will not
permit the Fund to terminate the transaction before its scheduled maturity. As
a result of these characteristics, each Fund will treat most over-the-counter
options (and the assets it segregates to cover its obligations thereunder) as
illiquid.
 
  The options and futures markets of foreign countries are small compared to
those of the United States and consequently are characterized in most cases by
less liquidity than are the U.S. markets. In addition, foreign markets may be
subject to less detailed reporting requirements and regulatory controls than
U.S. markets. Furthermore, investments in options in foreign markets are
subject to many of the same risks as other foreign investments. See "Foreign
Securities" above.
   
REPURCHASE AGREEMENTS     
   
  Each Fund may invest in repurchase agreements. In repurchase agreements, a
Fund buys securities from a seller, usually a bank or brokerage firm, with the
understanding that the seller will repurchase the securities at a higher price
at a later date. Such transactions afford an opportunity for a Fund to earn a
return on available cash at minimal market risk, although the Fund may be
subject to various delays and risks of loss if the seller is unable to meet
its obligations to repurchase.     
 
SECURITIES LENDING
 
  The Mid-Cap Growth, Mid-Cap Value, Small Cap Growth and Strategic Value
Funds may each lend its portfolio securities to broker-dealers or other
parties under contracts calling for the deposit by the borrower with the
Fund's custodian of cash collateral equal to at least the market value of the
securities loaned, marked to market on a daily basis. The Fund will continue
to benefit from interest or dividends on the securities loaned and will also
receive interest through investment of the cash collateral in short-term
liquid investments. No loans will be made if, as a result, the aggregate
amount of such loans outstanding at any time would exceed 33 1/3% of the
Fund's total assets (taken at current value). Any voting rights, or rights to
consent, relating to securities loaned pass to the borrower. However, if a
material event affecting the investment occurs, such loans will be called so
that the securities may be voted by the Fund. The Fund pays various fees in
connection with such loans, including shipping fees and reasonable custodial
or placement fees.
 
                                      22
<PAGE>
 
  Securities loans must be fully collateralized at all times, but involve some
credit risk to the Fund if the borrower defaults on its obligation and the
Fund is delayed or prevented from recovering the collateral.
 
YEAR 2000
 
  Many computer software systems in use today cannot properly process date-
related information from and after January 1, 2000. Should any of the computer
systems employed by the Funds' major service providers fail to process this
type of information properly, that could have a negative impact on the Funds'
operations and the services that are provided to the Funds' shareholders.
Loomis Sayles and the Distributor have each advised the Funds that they are
reviewing all of their computer systems with the goal of modifying or
replacing such systems prior to January 1, 2000, to the extent necessary to
foreclose any such negative impact. In addition, Loomis Sayles has been
advised by the Funds' custodian that it is also in the process of review its
systems with the same goal. As of the date of this prospectus, the Funds and
Loomis Sayles have no reason to believe that these goals will not be achieved.
Similarly, the values of certain of the portfolio securities held by the Funds
may be adversely affected by the inability of the securities' issuers or of
third parties to process this type of information properly.
 
                         THE FUND'S INVESTMENT ADVISER
 
  The Funds' investment adviser is Loomis Sayles, One Financial Center,
Boston, Massachusetts 02111. Founded in 1926, Loomis Sayles is one of the
country's oldest and largest investment firms. The general partner of Loomis
Sayles is a special purpose corporation that is an indirect wholly-owned
subsidiary of Nvest Companies, L.P. ("Nvest Companies"). Nvest Companies'
managing general partner, Nvest Corporation, is a direct wholly-owned
subsidiary of Metropolitan Life Insurance Company ("Met Life"), a mutual life
insurance company. Nvest Companies' advising general partner, Nvest, L.P., is
a publicly traded company listed on the New York Stock Exchange. Nvest
Corporation is the sole general partner of Nvest L.P.
 
  In addition to selecting and reviewing the Funds' investments, Loomis Sayles
provides executive and other personnel for the management of the Funds. The
Trust's board of trustees supervises Loomis Sayles' conduct of the affairs of
the Funds.
       
   
  As of October 31, 1998, Charles Schwab & Co. Inc. owned 22%, 22%, 79%, 40%,
31%, 16%, 63%, and 93% of the Core Value Fund, International Equity Fund, Mid-
Cap Growth Fund, Mid-Cap Value Fund, Small Cap Growth Fund, Small Cap Value
Fund, Strategic Value Fund, and Worldwide Fund,     
 
                                      23
<PAGE>
 
   
respectively. As of October 31, 1998, Asbestos Workers Local #84 Pension Fund,
John W. George, Jr. Trust and Green Tree Financial Corp. owned 6%, 6%, and 7%
of the Core Value Fund, respectively. As of October 31, 1998, Comerica Bank
and The Security Mutual Life Insurance Company of Lincoln Nebraska owned 12%
and 7% of the International Equity Fund, respectively. As of October 31, 1998,
American National Bank owned 9% of the Mid-Cap Growth Fund. As of October 31,
1998, Carey & Co. and John W. George, Jr. Trust each owned 8% of the Mid-Cap
Value Fund. As of October 31, 1998, Carey & Co., The community Foundation
Serving Coastal South Carolina, Covie & Co., Donaldson Lufkin Jenrette
Securities Corporation, Inc., Fifth Third Bank, and Trussal and Co. owned 6%,
12%, 6%, 8%, 6%, and 6% of the Small Cap Growth Fund. As of October 31, 1998,
Smith Barney, Inc. owned 10% of the Small Cap Value Fund. As of October 31,
1998, Lazard Freres & Co. and Pomona College owned 20% and 9% of the Strategic
Value Fund, respectively. Shareholders holding more than 25% of a Fund's
shares may be deemed to control the relevant Fund.     
   
  Jeffrey W. Wardlow, Vice President of the Trust and of Loomis Sayles, has
served as a portfolio manager of the Core Value Fund since its commencement of
investment operations in 1991. Issac H. Green, Director of Loomis Sayles and
Vice President of the Trust and of Loomis Sayles and James L. Carroll, Vice
President of Loomis Sayles and the Trust, have served as portfolio managers of
the Core Value Fund since October of 1997. Jerome A. Castellini, Vice
President of the Trust and of Loomis Sayles, has served as the portfolio
manager of the Mid-Cap Growth Fund since its commencement of investment
operations in 1997. Scott S. Pape, Vice President of the Trust and of Loomis
Sayles, has served as a portfolio manager of the Mid-Cap Growth Fund since its
commencement of investment operations in 1997. Dean A. Gulis, Vice President
of the Trust and of Loomis Sayles has served as a portfolio manager of the
Mid-Cap Value Fund since October of 1997, Dawn Alston Paige and Peter Ramsden,
each a Vice President of Loomis Sayles, have served as portfolio managers of
the Mid-Cap Value Fund since October 1998. Christopher R. Ely, Vice President
of the Trust and of Loomis Sayles, has served as the portfolio manager and
Philip C. Fine and David L. Smith, Vice Presidents of the Trust and of Loomis
Sayles, have served as assistant portfolio managers of the Small Cap Growth
Fund since its commencement of investment operations in 1997. Jeffrey C.
Petherick, Vice President of the Trust and of Loomis Sayles, has served as a
portfolio manager of the Small Cap Value Fund since 1993, and Mary C.
Champagne, Vice President of the Trust and of Loomis Sayles, has served as a
portfolio manager of the Small Cap Value Fund since 1995. Philip J. Schettewi,
Vice President of the Trust and Loomis Sayles, has served as the portfolio
manager of the Strategic Value Fund since its commencement of investment
operations in 1997. Daniel J. Fuss, President of the Trust and Executive Vice
President of Loomis Sayles, has served as the portfolio manager of the
domestic bonds sector of the Worldwide     
 
                                      24
<PAGE>
 
   
Fund since that Fund's commencement of investment operations in 1996. E. John
deBeer, Vice President of the Trust and of Loomis Sayles, has served as
portfolio manager of the international bonds sector of the Worldwide Fund
since that Fund's commencement of investment operations in 1996. Quentin P.
Faulkner, Vice President of the Trust and of Loomis Sayles, has served as the
portfolio manager of the domestic equities sector of the Worldwide Fund since
that Fund's commencement of investment operations in 1996. Paul H. Drexler,
Vice President of the Trust and of Loomis Sayles, has served as the portfolio
manager of the international equities sector of the Worldwide Fund since that
Fund's commencement of investment operations in 1996 and of the International
Equity Fund since 1996. Each of the foregoing, except Messrs. Carroll, Ely,
Fine, Gulis and Smith, have been employed by Loomis Sayles for at least five
years. Before joining Loomis Sayles in 1996, Mr. Carroll was a Managing
Director and Senior Energy Analyst at PaineWebber, Inc. Prior to joining
Loomis Sayles in 1996, Mr. Ely was Senior Vice President and Portfolio
Manager, and Messrs. Fine and Smith were Vice Presidents and Portfolio
Managers, of Keystone Investment Management Company, Inc. Prior to joining
Loomis Sayles in 1997, Mr. Gulis was a Principal and Director of Research at
Roney & Company.     
 
                                 FUND EXPENSES
 
  Each Fund pays Loomis Sayles a monthly investment advisory fee at the
following annual percentage rate of the Fund's average daily net assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                    RATE
   ----                                                                    ----
   <S>                                                                     <C>
   Core Value............................................................. .50%
   International Equity................................................... .75%
   Mid-Cap Growth......................................................... .75%
   Mid-Cap Value.......................................................... .75%
   Small Cap Value........................................................ .75%
   Small Cap Growth....................................................... .75%
   Strategic Value........................................................ .50%
   Worldwide.............................................................. .75%
</TABLE>    
 
  In addition to the investment advisory fee, each Fund pays all expenses not
expressly assumed by Loomis Sayles, including taxes, brokerage commissions,
fees and expenses of registering or qualifying the Fund's shares under federal
and state securities laws, fees of the Fund's custodian, transfer agent,
independent accountants and legal counsel, expenses of shareholders' and
trustees' meetings, 12b-1 fees, expenses of preparing, printing and mailing
prospectuses to existing shareholders and fees of trustees who are not
directors, officers or employees of Loomis Sayles and its affiliated
companies.
 
  Loomis Sayles has voluntarily agreed, for an indefinite period, to reduce
its advisory fees and/or bear other Fund expenses to the extent necessary to
limit
 
                                      25
<PAGE>
 
total operating expenses of the Institutional Class shares of each Fund to the
following annual percentage rate of the Fund's average net assets:
 
<TABLE>   
<CAPTION>
   FUND                                                                 RATE
   ----                                                                ------
   <S>                                                                 <C>
   Core Value.........................................................    .85%
   International Equity...............................................   1.00%
   Mid-Cap Growth.....................................................   1.00%
   Mid-Cap Value......................................................   1.00%
   Small Cap Value....................................................   1.00%
   Small Cap Growth...................................................   1.00%
   Strategic Value....................................................   1.00%
   Worldwide..........................................................   1.00%
</TABLE>    
 
  Loomis Sayles may change or terminate these voluntary arrangements at any
time, but the Funds' Prospectus would be supplemented to describe the change.
 
  Loomis Sayles may pay certain broker-dealers and financial intermediaries
whose customers are existing shareholders of the Funds a continuing fee in an
amount of up to .25% annually of the value of Fund shares held for those
customers' accounts. These fees are paid by Loomis Sayles out of its own
assets and are not assessed against the customers' accounts with the Funds.
 
                            PORTFOLIO TRANSACTIONS
 
  Portfolio turnover considerations will not limit Loomis Sayles' investment
discretion in managing the Funds' assets. The Funds anticipate that their
portfolio turnover rates will vary significantly from time to time depending
on the volatility of economic and market conditions. High portfolio turnover
may involve higher transaction costs and higher levels of taxable gains.
 
                            HOW TO PURCHASE SHARES
 
  An investor may make an initial purchase of shares of any Fund by submitting
a completed application form and payment to:
 
      Boston Financial Data Services
      P.O. Box 8314
      Boston, Massachusetts 02266-8314
      Attn: Loomis Sayles Funds
 
  The minimum initial investment for the Institutional Class of each Fund's
shares is $1 million in that Fund. A $2,500 minimum investment applies to the
current and retired trustees of the Trust, investment advisory clients of
Loomis
 
                                      26
<PAGE>
 
Sayles (and their directors, officers and employees), and current and retired
employees of Loomis Sayles and the parents, spouses and children of the
foregoing. The minimum investment may be waived in whole or in part by Loomis
Sayles in its sole discretion. Subsequent investments must be at least $50.
 
  Shares of any Fund may be purchased by (i) cash, (ii) exchanging
Institutional Class Shares of any Fund (or any other series of Loomis Sayles
Funds) provided the value of the shares exchanged meets the investment minimum
of the Fund into which the exchange is made, (iii) exchanging securities on
deposit with a custodian acceptable to Loomis Sayles or (iv) a combination of
such securities and cash. Purchase of shares of the Fund in exchange for
securities is subject in each case to the determination by Loomis Sayles that
the securities to be exchanged are acceptable for purchase by the Fund. In all
cases Loomis Sayles reserves the right to reject any securities that are
proposed for exchange. Securities accepted by Loomis Sayles in exchange for
Fund shares will be valued in the same manner as the Fund's assets as
described below as of the time of the Fund's next determination of net asset
value after such acceptance. All dividends and subscription or other rights
which are reflected in the market price of accepted securities at the time of
valuation become the property of the Fund and must be delivered to the Fund
upon receipt by the investor from the issuer. A gain or loss for federal
income tax purposes would be realized upon the exchange by an investor that is
subject to federal income taxation, depending upon the investor's basis in the
securities tendered. An investor who wishes to purchase shares by exchanging
securities should obtain instructions by calling 800-633-3330 option 5 and
asking for the Loomis Sayles Shareholder Services Group.
 
  Loomis Sayles will not approve the acceptance of securities in exchange for
shares of any Fund unless (1) Loomis Sayles, in its sole discretion, believes
the securities are appropriate investments for the Fund; (2) the investor
represents and agrees that all securities offered to the Fund can be resold by
the Fund without restriction under the Securities Act of 1933, as amended (the
"Securities Act") or otherwise; and (3) the securities are eligible to be
acquired under the Fund's investment policies and restrictions. No investor
owning 5% or more of Fund's shares may purchase additional shares of that Fund
by exchange of securities.
 
  All purchases made by check should be in U.S. dollars and made payable to
State Street Bank. Third party checks will not be accepted. When purchases are
made by check or periodic account investment, redemption will not be allowed
until the investment being redeemed has been in the account for 15 calendar
days.
 
                                      27
<PAGE>
 
  Upon acceptance of an investor's order, BFDS opens an account, applies the
payment to the purchase of full and fractional Fund shares and mails a
statement of the account confirming the transaction.
 
  After an account has been established, an investor may send subsequent
investments at any time directly to BFDS at the above address. The remittance
must be accompanied by either the account identification slip detached from a
statement of account or a note containing sufficient information to identify
the account, i.e., the Fund name and the investor's account number or name and
social security number.
 
  Subsequent investments can also be made by federal funds wire. Investors
should instruct their banks to wire federal funds to State Street Bank and
Trust Company, ABA #011000028. The text of the wire should read as follows:
"$    amount, STATE STREET BOS ATTN Mutual Funds. Credit Fund (Fund Name and
Institutional Class), DDA #9904-622-9, Account Name, Account Number." A bank
may charge a fee for transmitting funds by wire.
 
  Each Fund and the Distributor reserve the right to reject any purchase
order, including orders in connection with exchanges, for any reason which the
Fund or the Distributor in its sole discretion deems appropriate. Although the
Funds do not presently anticipate that they will do so, each Fund reserves the
right to suspend or change the terms of the offering of its shares.
 
  The price an investor pays will be the per share net asset value next
calculated after a proper investment order is received by the Trust's transfer
or other agent or subagent. Shares of each Fund are sold with no sales charge.
The net asset value of each Fund's shares is calculated once daily as of the
close of regular trading on the New York Stock Exchange on each day the
Exchange is open for trading, by dividing the Fund's net assets by the number
of shares outstanding. Portfolio securities are valued at their market value
as more fully described in the Statement of Additional Information.
 
  The Distributor may accept telephone orders from broker-dealers who have
been previously approved by the Distributor. It is the responsibility of such
broker-dealers to promptly forward purchase or redemption orders to the
Distributor. Although there is no sales charge imposed by the Fund or the
Distributor, broker-dealers may charge the investor a transaction-based fee or
other fee for their services at either the time of purchase or the time of
redemption. Such charges may vary among broker-dealers but in all cases will
be retained by the broker-dealer and not remitted to the Fund.
 
  Each Fund also offers a Retail Class of shares that has a $25,000 minimum
investment for certain categories of investors, is offered through
intermediaries and bears higher expenses. Because of its lower expenses, the
Institutional Class
 
                                      28
<PAGE>
 
of shares of each Fund is expected to have a higher total return than the
Retail Class of shares.
 
  The Loomis Sayles Small Cap Value Fund also offers an Admin Class of shares
that is offered exclusively through intermediaries, who will be the record
owners of the shares. Because of its lower expenses, the Institutional Class
of shares of the Loomis Sayles Small Cap Value Fund is expected to have a
higher total return than the Admin Class of shares.
 
                             SHAREHOLDER SERVICES
 
  The Funds offer the following shareholder services, which are more fully
described in the Statement of Additional Information. Explanations and forms
are available from BFDS. Telephone redemption and exchange privileges will be
established automatically when an investor opens an account unless an investor
elects on the application to decline the privileges. Other privileges must be
specifically elected. A signature guarantee will be required to establish a
privilege after an account is opened.
   
  FREE EXCHANGE PRIVILEGE. The Institutional Class shares of any Fund may be
exchanged for shares of the Institutional Class of any other Fund (or any
other fund that is a series of Loomis Sayles Funds and that offers
Institutional Class shares) or for shares of certain money market funds
advised by New England Funds Management, L.P., an affiliate of Loomis Sayles,
provided the value of the shares exchanged meets the investment minimum of
that Fund and, in the case of Loomis Sayles High Yield Fund and Loomis Sayles
U.S. Government Securities Fund, Loomis Sayles has approved the exchange of
shares. Exchanges may be made by written instructions or by telephone, unless
an investor elected on the application to decline telephone exchange
privileges. The exchange privilege should not be viewed as a means for taking
advantage of short-term swings in the market, and the Funds reserve the right
to terminate or limit the privilege of any shareholder who makes more than
four exchanges in any calendar year. The Funds may terminate or change the
terms of the exchange privilege at any time, upon 60 days' notice to
shareholders. An exchange is a taxable event for federal income tax purposes
in which a gain or loss would be realized by an investor that is subject to
federal income taxation.     
 
  RETIREMENT PLANS. The Funds' shares may be purchased by all types of tax-
deferred retirement plans. Loomis Sayles makes available retirement plan forms
for IRAs.
 
  SYSTEMATIC WITHDRAWAL PLAN. If the value of an account is at least $25,000,
an investor may have periodic cash withdrawals automatically paid to the
investor or any person designated by the investor.
 
                                      29
<PAGE>
 
  AUTOMATIC INVESTMENT PLAN. Voluntary monthly investments of at least $50 may
be made automatically by pre-authorized withdrawals from an investor's
checking account.
 
                             HOW TO REDEEM SHARES
 
  An investor can redeem shares by sending a written request to Boston
Financial Data Services, Inc., P.O. Box 8314, Boston, Massachusetts 02266. As
described below, an investor may also redeem shares by calling BFDS at 800-
626-9390. Proceeds resulting from a written or telephone redemption request
can be wired to an investor's bank account or sent by check in the name of the
registered owners to their record address.
 
  The written request must include the name of the Fund, the account number,
the exact name(s) in which the shares are registered, and the number of shares
or the dollar amount to be redeemed. All owners of the shares must sign the
request in the exact names in which the shares are registered (this appears on
an investor's confirmation statement) and should indicate any special capacity
in which they are signing (such as trustee or custodian or on behalf of a
partnership, corporation or other entity). Investors requesting that
redemption proceeds be wired to their bank accounts must provide specific wire
instructions.
 
  If (1) an investor is redeeming shares worth more than $50,000, (2) an
investor is requesting that the proceeds check be made out to someone other
than the registered owners or be sent to an address other than the record
address, (3) the account registration has changed within the last 30 days or
(4) an investor is instructing us to wire the proceeds to a bank account not
designated on the application, the investor must have his or her signature
guaranteed by an eligible guarantor. This requirement may be waived by Loomis
Sayles in its sole discretion. Eligible guarantors include commercial banks,
trust companies, savings associations, credit unions and brokerage firms that
are members of domestic securities exchanges. Before submitting the redemption
request, an investor should verify with the guarantor institution that it is
an eligible guarantor. Signature guarantees by notaries public are not
acceptable.
 
  When an investor telephones a redemption request, the proceeds are wired to
the bank account previously chosen by the investor. A wire fee (currently $5)
will be deducted from the proceeds. A telephonic redemption request must be
received by BFDS prior to the close of regular trading on the New York Stock
Exchange. If an investor telephones a request to BFDS after the Exchange
closes or on a day when the Exchange is not open for business, BFDS cannot
accept the request and a new one will be necessary.
 
                                      30
<PAGE>
 
  If an investor decides to change the bank account to which proceeds are to
be wired, an investor must send in this change in writing with a signature
guarantee. Telephonic redemptions may only be made if an investor's bank is a
member of the Federal Reserve System or has a correspondent bank that is a
member of the System. Unless an investor indicates otherwise on the account
application, BFDS will be authorized to act upon redemption and exchange
instructions received by telephone from the investor or any person claiming to
act as the investor's representative who can provide BFDS with the investor's
account registration and address as it appears on the records of State Street
Bank. BFDS will employ these or other reasonable procedures to confirm that
instructions communicated by telephone are genuine; the Fund, State Street
Bank, BFDS, the Distributor and Loomis Sayles will not be liable for any
losses due to unauthorized or fraudulent instructions if these or other
reasonable procedures are followed. For information, consult BFDS. In times of
heavy market activity, an investor who encounters difficulty in placing a
redemption or exchange order by telephone may wish to place the order by mail
as described above.
 
  The redemption price will be the net asset value per share next determined
after the redemption request and any necessary special documentation are
received by BFDS in proper form.
 
  Proceeds resulting from a written redemption request will normally be mailed
to an investor within seven days after receipt of the investor's request in
good order. Telephonic redemption proceeds will normally be wired to an
investor's bank on the first business day following receipt of a proper
redemption request. If an investor purchased shares by check and the check was
deposited less than fifteen days prior to the redemption request, the Fund may
withhold redemption proceeds until the check has cleared.
 
  The Fund may suspend the right of redemption and may postpone payment for
more than seven days when the New York Stock Exchange is closed for other than
weekends or holidays, or if permitted by the rules of the SEC when trading on
the Exchange is restricted or during an emergency which makes it impracticable
for the Fund to dispose of its securities or to determine fairly the value of
its net assets, or during any other period permitted by the SEC for the
protection of investors.
 
                    CALCULATION OF PERFORMANCE INFORMATION
 
  "Total return" for the one-, five- and ten-year periods (or for the life of
a class, if shorter) through the most recent calendar quarter represents the
average annual compounded rate of return on an investment of $1,000 in a Fund.
Total return may also be presented for other periods.
 
                                      31
<PAGE>
 
                DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAXES
 
  The Funds declare and pay their net investment income to shareholders as
dividends annually. Each Fund also distributes all of its net capital gains
realized from the sale of portfolio securities. Any capital gain distributions
are normally made annually, but may, to the extent permitted by law, be made
more frequently as deemed advisable by the trustees of the Trust. The Trust's
trustees may change the frequency with which the Funds declare or pay
dividends.
   
  Dividends and capital gain distributions will automatically be reinvested in
additional shares of the same Fund unless an investor has elected to receive
cash. Each Fund intends to qualify as a regulated investment company under the
Internal Revenue Code of 1986, as amended. As such, so long as a Fund
distributes substantially all its net investment income and net capital gains
to its shareholders, the Fund itself does not pay any federal income tax to
the extent such income and gains are so distributed.     
   
  An investor's income dividends and short-term capital gain distributions
(that is, net gains from securities held for not more than a year) are taxable
as ordinary income whether distributed in cash or additional shares.
Distributions designated by all Funds as deriving from net gains on securities
held for more than one year will be taxable as such (generally at a 20% rate
for noncorporate shareholders) whether distributed in cash or additional
shares and regardless of how long an investor has owned shares of the Fund.
       
  A dividend or distribution made shortly after the purchase of shares of a
Fund by a shareholder, although in effect a return of capital to that
particular shareholder, would be taxable to him or her as described above. If
a shareholder held shares six months or less and during that period received a
distribution of net capital gains, any loss realized on the sale of such
shares during such six-month period would be a long-term capital loss to the
extent of such distribution.     
 
  Each Fund is required to withhold 31% of any redemption proceeds (including
the value of shares exchanged) and all income dividends and capital gain
distributions it pays to an investor (1) if an investor does not provide a
correct, certified taxpayer identification number, (2) if the Fund is notified
that an investor has underreported income in the past, or (3) if an investor
fails to certify to the Fund that the investor is not subject to such
withholding.
   
  Certain designated dividends from the Funds are expected to be eligible for
the dividends-received deduction for corporate shareholders that meet a
holding period requirement.     
 
  State Street Bank will send each investor and the IRS an annual statement
detailing federal tax information, including information about dividends and
distributions paid to the investor during the preceding year. Be sure to keep
this
 
                                      32
<PAGE>
 
statement as a permanent record. A fee may be charged for any duplicate
information that an investor requests.
 
NOTE: The foregoing summarizes certain tax consequences of investing in the
         Funds. Before investing, an investor should consult his or her own
         tax adviser for more information concerning the federal, foreign,
         state and local tax consequences of investing in, redeeming or
         exchanging Fund shares.
 
                                      33
<PAGE>
 
INVESTMENT ADVISER 
Loomis, Sayles & Company, L.P. 
One Financial Center 
Boston, Massachusetts 02111
 
DISTRIBUTOR 
Loomis Sayles Distributors, L.P. 
One Financial Center 
Boston, Massachusetts 02111
 
TRANSFER AND DIVIDEND PAYING AGENT 
AND CUSTODIAN OF ASSETS 
State Street Bank and Trust Company 
Boston, Massachusetts 02102
 
SHAREHOLDER SERVICING AGENT FOR 
STATE STREET BANK AND TRUST COMPANY 
Boston Financial Data Services, Inc. 
P.O. Box 8314 
Boston, Massachusetts 02266
 
LEGAL COUNSEL 
Ropes & Gray 
One International Place 
Boston, Massachusetts 02110

INDEPENDENT ACCOUNTANTS
    
PricewaterhouseCoopers LLP     
One Post Office Square 
Boston, Massachusetts 02109
<PAGE>
 
[LOGO OF LOOMIS SAYLES FUNDS APPEARS HERE] 
 
                            STATEMENT OF ADDITIONAL
                                  INFORMATION
                                                              
                                                           JANUARY 1, 1999     
   
  THIS STATEMENT OF ADDITIONAL INFORMATION IS NOT A PROSPECTUS. THIS STATEMENT
OF ADDITIONAL INFORMATION RELATES TO THE PROSPECTUS OR PROSPECTUSES OF EACH
SERIES ("FUND") OF LOOMIS SAYLES FUNDS DATED JANUARY 1, 1999, AS REVISED FROM
TIME TO TIME. EACH REFERENCE TO THE PROSPECTUS IN THIS STATEMENT OF ADDITIONAL
INFORMATION SHALL INCLUDE ALL OF THE FUNDS' CURRENT PROSPECTUSES, UNLESS
OTHERWISE NOTED. THIS STATEMENT OF ADDITIONAL INFORMATION SHOULD BE READ IN
CONJUNCTION WITH THE APPLICABLE PROSPECTUS. A COPY OF EACH PROSPECTUS MAY BE
OBTAINED FROM LOOMIS SAYLES FUNDS, ONE FINANCIAL CENTER, BOSTON, MASSACHUSETTS
02111.     
<PAGE>
 
                               TABLE OF CONTENTS
 
<TABLE>   
<CAPTION>
                                                                            PAGE
                                                                            ----
<S>                                                                         <C>
INVESTMENT OBJECTIVES, POLICIES AND RESTRICTIONS...........................   3
MANAGEMENT OF THE TRUST....................................................  10
INVESTMENT ADVISORY AND OTHER SERVICES.....................................  23
PORTFOLIO TRANSACTIONS AND BROKERAGE.......................................  26
DESCRIPTION OF THE TRUST...................................................  28
  How to Buy Shares........................................................  30
  Net Asset Value..........................................................  30
SHAREHOLDER SERVICES.......................................................  31
  Open Accounts............................................................  31
  Systematic Withdrawal Plan...............................................  31
  Exchange Privilege.......................................................  32
  IRAs.....................................................................  32
  Redemptions..............................................................  32
INCOME DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAX STATUS ...............  33
FINANCIAL STATEMENTS.......................................................  36
CALCULATION OF YIELD AND TOTAL RETURN......................................  36
PERFORMANCE COMPARISONS....................................................  37
PERFORMANCE DATA...........................................................  40
APPENDIX A--PUBLICATIONS THAT MAY CONTAIN FUND INFORMATION.................  44
APPENDIX B--ADVERTISING AND PROMOTIONAL LITERATURE.........................  46
</TABLE>    
 
                                       2
<PAGE>
 
               INVESTMENT OBJECTIVES, POLICIES AND RESTRICTIONS
 
  The investment objective and policies of each series ("Fund") of Loomis
Sayles Funds (the "Trust"), are summarized in the Prospectus under "Investment
Objectives and Policies" and "More Information About the Funds' Investments
and Risk Factors." The investment policies of each Fund set forth in the
Prospectus and in this Statement of Additional Information may be changed by
the Funds' adviser, subject to review and approval by the Trust's board of
trustees, without shareholder approval except that the investment objective of
each Fund as set forth in the Prospectus and any Fund policy explicitly
identified as "fundamental" may not be changed without the approval of the
holders of a majority of the outstanding shares of the relevant Fund (which in
the Prospectus and this Statement of Additional Information means the lesser
of (i) 67% of the shares of that Fund represented at a meeting at which 50% of
the outstanding shares are represented or (ii) more than 50% of the
outstanding shares). Except in the case of the 15% limitation on illiquid
securities, the percentage limitations set forth below and in the Prospectuses
will apply at the time a security is purchased and will not be considered
violated unless an excess or deficiency occurs or exists immediately after and
as a result of such purchase.
 
  In addition to its investment objective and policies set forth in the
Prospectus, the following investment restrictions are policies of each Fund
(and those marked with an asterisk are fundamental policies of each Fund):
 
Each Fund will not:
 
    (1) Invest in companies for the purpose of exercising control or
  management.
 
    *(2) Act as underwriter, except to the extent that, in connection with
  the disposition of portfolio securities, it may be deemed to be an
  underwriter under certain federal securities laws.
 
    *(3) Invest in oil, gas or other mineral leases, rights or royalty
  contracts or in real estate, commodities or commodity contracts. (This
  restriction does not prevent any Fund from engaging in transactions in
  futures contracts relating to securities indexes, interest rates or
  financial instruments or options, or from investing in issuers that invest
  or deal in the foregoing types of assets or from purchasing securities that
  are secured by real estate.)
 
    *(4) Make loans, except that each of the Mid-Cap Growth, Mid-Cap Value,
  Small Cap Growth, Strategic Value, Investment Grade Bond and Intermediate
  Maturity Bond Funds may lend its portfolio securities to the extent
  permitted under the Investment Company Act of 1940 (the "1940 Act"). (For
  purposes of this investment restriction, neither (i) entering into
  repurchase agreements nor (ii) purchasing bonds, debentures, commercial
  paper, corporate notes and similar evidences of indebtedness, which are a
  part of an issue to the public, is considered the making of a loan.)
     
    (5) With respect to 75% of its total assets, purchase any security (other
  than a U.S. Government Security) if, as a result, more than 5% of the
  Fund's total assets (taken at current value) would then be invested in
  securities of a single issuer. (For purposes of this restriction, the
  Municipal Bond Fund treats each state and each separate political
  subdivision, agency, authority or instrumentality of such state, each
  multistate agency or authority, and each guarantor, if any, of obligations
  of any such issuer, as a separate issuer, provided that the assets and
  revenues of the issuer are separate from those of the government(s) that
  created the subdivision, agency, authority or instrumentality.)     
     
    (6) With respect to 75% of its total assets, acquire more than 10% of the
  outstanding voting securities of an issuer.     
 
    (7) Pledge, mortgage, hypothecate or otherwise encumber any of its
  assets, except that each Fund may pledge assets having a value not
  exceeding 10% of its total assets to secure borrowings permitted by
  restriction (9) below. (For the purpose of this restriction, collateral
  arrangements with respect to options, futures contracts and options on
  futures contracts and with respect to initial and variation margin are not
  deemed to be a pledge or other encumbrance of assets.)
 
    *(8) Purchase any security (other than U.S. Government Securities) if, as
  a result, more than 25% of the Fund's total assets (taken at current value)
  would be invested in any one industry (in the utilities
 
                                       3
<PAGE>
 
  category, gas, electric, water and telephone companies will be considered
  as being in separate industries.) Tax-exempt securities issued by
  governments or political subdivisions of governments and purchased by the
  Municipal Bond Fund are not subject to this restriction, since such issuers
  are not members of any industry.
 
    *(9) Borrow money in excess of 10% of its total assets (taken at cost) or
  5% of its total assets (taken at current value), whichever is lower, nor
  borrow any money except as a temporary measure for extraordinary or
  emergency purposes.
 
    (10) Purchase securities on margin (except such short term credits as are
  necessary for clearance of transactions); or make short sales (except
  where, by virtue of ownership of other securities, it has the right to
  obtain, without payment of additional consideration, securities equivalent
  in kind and amount to those sold).
 
    (11) Participate on a joint or joint and several basis in any trading
  account in securities. (The "bunching" of orders for the purchase or sale
  of portfolio securities with Loomis Sayles or accounts under its management
  to reduce brokerage commissions, to average prices among them or to
  facilitate such transactions is not considered a trading account in
  securities for purposes of this restriction.)
 
    (12) Purchase any illiquid security, including any security that is not
  readily marketable, if, as a result, more than 15% of the Fund's net assets
  (based on current value) would then be invested in such securities.
 
    (13) Write or purchase puts, calls or combinations of both except that
  each Fund may (1) acquire warrants or rights to subscribe to securities of
  companies issuing such warrants or rights, or of parents or subsidiaries of
  such companies, (2) purchase and sell put and call options on securities
  and (3) write, purchase and sell put and call options on currencies and may
  enter into currency forward contracts.

    *(14) Issue senior securities. (For the purpose of this restriction none
  of the following is deemed to be a senior security: any pledge or other
  encumbrance of assets permitted by restriction (7) above; any borrowing
  permitted by restriction (9) above; any collateral arrangements with
  respect to options, futures contracts and options on futures contracts and
  with respect to initial and variation margin; and the purchase or sale of
  options, forward contracts, futures contracts or options on futures
  contracts.)
 
  Although the Funds have no current intention of investing in repurchase
agreements, they intend, based on the views of the staff of the Securities and
Exchange Commission (the "SEC"), to restrict their investments in repurchase
agreements maturing in more than seven days, together with other investments
in illiquid securities, to the percentage permitted by restriction (12) above.
 
U.S. GOVERNMENT SECURITIES
 
  U.S. Government Securities include direct obligations of the U.S. Treasury,
as well as securities issued or guaranteed by U.S. Government agencies,
authorities and instrumentalities, including, among others, the Government
National Mortgage Association, the Federal Home Loan Mortgage Corporation, the
Federal National Mortgage Association, the Federal Housing Administration, the
Resolution Funding Corporation, the Federal Farm Credit Banks, the Federal
Home Loan Bank, the Tennessee Valley Authority, the Student Loan Marketing
Association and the Small Business Administration. More detailed information
about some of these categories of U.S. Government Securities follows.
 
  U.S. Treasury Bills--Direct obligations of the United States Treasury which
are issued in maturities of one year or less. No interest is paid on Treasury
bills; instead, they are issued at a discount and repaid at full face value
when they mature. They are backed by the full faith and credit of the United
States Government.
 
  U.S. Treasury Notes and Bonds--Direct obligations of the United States
Treasury issued in maturities that vary between one and forty years, with
interest normally payable every six months. They are backed by the full faith
and credit of the United States Government.
 
  "Ginnie Maes"--Debt securities issued by a mortgage banker or other
mortgagee which represent an interest in a pool of mortgages insured by the
Federal Housing Administration or the Farmer's Home
 
                                       4
<PAGE>
 
Administration or guaranteed by the Veterans Administration. The Government
National Mortgage Association ("GNMA") guarantees the timely payment of
principal and interest when such payments are due, whether or not these
amounts are collected by the issuer of these certificates on the underlying
mortgages. An assistant attorney general of the United States has rendered an
opinion that the guarantee by GNMA is a general obligation of the United
States backed by its full faith and credit. Mortgages included in single
family or multi-family residential mortgage pools backing an issue of Ginnie
Maes have a maximum maturity of up to 30 years. Scheduled payments of
principal and interest are made to the registered holders of Ginnie Maes (such
as the Fund) each month. Unscheduled prepayments may be made by homeowners, or
as a result of a default. Prepayments are passed through to the registered
holder of Ginnie Maes along with regular monthly payments of principal and
interest.
   
  "Fannie Maes"--Fannie Mae is a government-sponsored corporation owned
entirely by private stockholders that purchases residential mortgages from a
list of approved seller/servicers. Fannie Maes are pass-through securities
issued by Fannie Mae that are guaranteed as to timely payment of principal and
interest by Fannie Mae but are not backed by the full faith and credit of the
United States Government.     
 
  "Freddie Macs"--The Federal Home Loan Mortgage Corporation ("FHLMC") is a
corporate instrumentality of the United States Government. Freddie Macs are
participation certificates issued by FHLMC that represent an interest in
residential mortgages from FHLMC's National Portfolio. FHLMC guarantees the
timely payment of interest and ultimate collection of principal, but Freddie
Macs are not backed by the full faith and credit of the United States
Government.
 
  As described in the Prospectus, U.S. Government Securities generally do not
involve the same credit risks associated with investments in other types of
fixed-income securities, although, as a result, the yields available from U.S.
Government Securities are generally lower than the yields available from
corporate fixed-income securities. Like other fixed-income securities,
however, the values of U.S. Government Securities change as interest rates
fluctuate. Fluctuations in the value of portfolio securities will not affect
interest income on existing portfolio securities but will be reflected in the
Fund's net asset value.
 
WHEN-ISSUED SECURITIES
 
  As described in the Prospectus, each Fund may enter into agreements with
banks or broker-dealers for the purchase or sale of securities at an agreed-
upon price on a specified future date. Such agreements might be entered into,
for example, when a Fund that invests in fixed income securities anticipates a
decline in interest rates and is able to obtain a more advantageous yield by
committing currently to purchase securities to be issued later. When a Fund
purchases securities in this manner (i.e. on a when-issued or delayed-delivery
basis), it is required to create a segregated account with the Trust's
custodian and to maintain in that account liquid assets in an amount equal to
or greater than, on a daily basis, the amount of the Fund's when-issued or
delayed-delivery commitments. Each Fund will make commitments to purchase on a
when-issued or delayed-delivery basis only securities meeting that Fund's
investment criteria. The Fund may take delivery of these securities or, if it
is deemed advisable as a matter of investment strategy, the Fund may sell
these securities before the settlement date. When the time comes to pay for
when-issued or delayed-delivery securities, the Fund will meet its obligations
from then available cash flow or the sale of securities, or from the sale of
the when-issued or delayed-delivery securities themselves (which may have a
value greater or less than the Fund's payment obligation).
 
CONVERTIBLE SECURITIES
 
  Convertible securities include corporate bonds, notes or preferred stocks of
U.S. or foreign issuers that can be converted into (that is, exchanged for)
common stocks or other equity securities. Convertible securities also include
other securities, such as warrants, that provide an opportunity for equity
participation. Because convertible securities can be converted into equity
securities, their values will normally vary in some proportion
 
                                       5
<PAGE>
 
with those of the underlying equity securities. Convertible securities usually
provide a higher yield than the underlying equity, however, so that the price
decline of a convertible security may sometimes be less substantial than that
of the underlying equity security.
 
ZERO COUPON BONDS
 
  Zero coupon bonds are debt obligations that do not entitle the holder to any
periodic payments of interest either for the entire life of the obligation or
for an initial period after the issuance of the obligations. Such bonds are
issued and traded at a discount from their face amounts. The amount of the
discount varies depending on such factors as the time remaining until maturity
of the bonds, prevailing interest rates, the liquidity of the security and the
perceived credit quality of the issuer. The market prices of zero coupon bonds
generally are more volatile than the market prices of securities that pay
interest periodically and are likely to respond to changes in interest rates
to a greater degree than do non-zero coupon bonds having similar maturities
and credit quality. In order to satisfy a requirement for qualification as a
"regulated investment company" under the Internal Revenue Code (the "Code"),
each Fund must distribute each year at least 90% of its net investment income,
including the original issue discount accrued on zero coupon bonds. Because a
Fund investing in zero coupon bonds will not on a current basis receive cash
payments from the issuer in respect of accrued original issue discount, the
Fund may have to distribute cash obtained from other sources in order to
satisfy the 90% distribution requirement under the Code. Such cash might be
obtained from selling other portfolio holdings of the Fund. In some
circumstances, such sales might be necessary in order to satisfy cash
distribution requirements even though investment considerations might
otherwise make it undesirable for the Fund to sell such securities at such
time.
 
REPURCHASE AGREEMENTS
 
  Each Fund may enter into repurchase agreements, by which the Fund purchases
a security and obtains a simultaneous commitment from the seller (a bank or,
to the extent permitted by the 1940 Act, a recognized securities dealer) to
repurchase the security at an agreed upon price and date (usually seven days
or less from the date of original purchase). The resale price is in excess of
the purchase price and reflects an agreed upon market rate unrelated to the
coupon rate on the purchased security. Such transactions afford the Funds the
opportunity to earn a return on temporarily available cash at minimal market
risk. While the underlying security may be a bill, certificate of
indebtedness, note or bond issued by an agency, authority or instrumentality
of the United States Government, the obligation of the seller is not
guaranteed by the U.S. Government and there is a risk that the seller may fail
to repurchase the underlying security. In such event, the Fund would attempt
to exercise rights with respect to the underlying security, including possible
disposition in the market. However, the Fund may be subject to various delays
and risks of loss, including (a) possible declines in the value of the
underlying security during the period while the Fund seeks to enforce its
rights thereto, (b) possible reduced levels of income and lack of income
during this period and (c) inability to enforce rights and the expenses
involved in attempted enforcement.
 
REAL ESTATE INVESTMENT TRUSTS
   
  Each Fund may invest in REITs. REITs involve certain unique risks in
addition to those risks associated with investing in the real estate industry
in general (such as possible declines in the value of real estate, lack of
availability of mortgage funds or extended vacancies of property). Equity
REITs may be affected by changes in the value of the underlying property owned
by the REITs, while mortgage REITs may be affected by the quality of any
credit extended. REITs are dependent upon management skills, are not
diversified, are subject to heavy cash flow dependency, risks of default by
borrowers and self-liquidation. REITs are also subject to the possibilities of
failing to qualify for tax-free pass-through of income under the Code, and
failing to maintain their exemptions from registration under the Investment
Company Act of 1940 (the "1940 Act").     
   
  Investment in REITs involves risk similar to those associated with investing
in small capitalization companies. REITs may have limited financial resources,
may trade less frequently and in a limited volume and may be subject to more
abrupt or erratic price movements than larger securities.     
 
                                       6
<PAGE>
 
RULE 144A SECURITIES
 
  Each of the Funds may purchase Rule 144A securities. These are privately
offered securities that can be resold only to certain qualified institutional
buyers. Rule 144A securities are treated as illiquid, unless Loomis Sayles has
determined, under guidelines established by the Trust's trustees, that the
particular issue of Rule 144A securities is liquid. Under the guidelines,
Loomis Sayles considers such factors as: (1) the frequency of trades and
quotes for a security; (2) the number of dealers willing to purchase or sell
the security and the number of other potential purchasers; (3) dealer
undertakings to make a market in the security; and (4) the nature of the
security and the nature of the marketplace trades therefor.
 
TAX EXEMPT BONDS
 
  Tax exempt bonds include debt obligations issued to obtain funds for various
public purposes, including the construction of a wide range of public
facilities such as bridges, highways, hospitals, housing, mass transportation,
schools, streets, and water and sewer works. Other public purposes for which
tax exempt bonds may be issued include the refunding of outstanding
obligations, obtaining funds for general operating expenses, and obtaining
funds to lend to other public institutions and facilities. In addition, prior
to the Tax Reform Act of 1986, certain debt obligations known as industrial
development bonds could be issued by or on behalf of public authorities to
obtain funds to provide privately operated housing facilities, sports
facilities, convention or trade show facilities, airport, mass transit, port
or parking facilities, air or water pollution control facilities and certain
local facilities for water supply, gas, electricity, or sewage or solid waste
disposal. Such obligations are included within the term tax exempt bonds if
the interest paid thereon is, in the opinion of bond counsel, exempt from
federal income tax. Interest on certain industrial development bonds used to
fund the construction, equipment, repair or improvement of privately operated
industrial or commercial facilities may also be exempt from federal income
tax. The Tax Reform Act of 1986 eliminated some types of tax exempt industrial
revenue bonds but retained others under the general category of "private
activity bonds." The interest on so-called "private activity bonds" is exempt
from ordinary federal income taxation but is treated as a tax preference item
in computing a shareholder's alternative minimum tax liability. The Municipal
Bond Fund may invest up to 20% of its net assets in private activity bonds.
 
  The Municipal Bond Fund may not be a desirable investment for "substantial
users" of facilities financed by industrial development bonds or for "related
persons" of substantial users. See "Income Dividends, Capital Gain
Distributions and Tax Status."
 
  The two principal classifications of tax exempt bonds are general obligation
bonds and limited obligation (or revenue) bonds. General obligation bonds are
obligations involving the credit of an issuer possessing taxing power and are
payable from the issuer's general unrestricted revenues and not from any
particular fund or source. The characteristics and method of enforcement of
general obligation bonds vary according to the law applicable to the
particular issuer, and payment may be dependent upon an appropriation by the
issuer's legislative body. Limited obligation bonds are payable only from the
revenues derived from a particular facility or class of facilities, or in some
cases from the proceeds of a special excise or other specific revenue source
such as the user of the facility. Tax exempt industrial development bonds and
private activity bonds are in most cases revenue bonds and generally are not
payable from the unrestricted revenues of the issuer. The credit and quality
of such bonds are usually directly related to the credit standing of the
corporate user of the facilities. Principal and interest on such bonds is the
responsibility of the corporate user (and any guarantor).
 
  Prices and yields on tax exempt bonds are dependent on a variety of factors,
including general money market conditions, the financial condition of the
issuer, general conditions of the tax exempt bond market, the size of a
particular offering, the maturity of the obligation and the rating of the
issue. A number of these factors, including the ratings of particular issues,
are subject to change from time to time. Information about the financial
condition of an issuer of tax exempt bonds may not be as extensive as that
made available by corporations whose securities are publicly traded.
 
  As noted in the Prospectus, obligations of issuers of tax exempt bonds are
subject to the provisions of bankruptcy, insolvency and other laws, such as
the Federal Bankruptcy Reform Act of 1978, affecting the rights
 
                                       7
<PAGE>
 
and remedies of creditors. Congress or state legislatures may seek to extend
the time for payment of principal or interest, or both, or to impose other
constraints upon enforcement of such obligations. There is also the
possibility that, as a result of litigation or other conditions, the power or
ability of issuers to meet their obligations for the payment of interest and
principal on their tax exempt bonds may be materially affected, or their
obligations may be found to be invalid or unenforceable. Such litigation or
conditions may from time to time have the effect of introducing uncertainties
in the market for tax exempt bonds or certain segments thereof, or materially
affecting the credit risk with respect to particular bonds. Adverse economic,
business, legal or political developments might affect all or a substantial
portion of the Fund's tax exempt bonds in the same manner.
 
  From time to time the Municipal Bond Fund may have less than 80% of its net
assets invested in tax exempt bonds (1) for defensive purposes when deemed
prudent in the judgment of Loomis Sayles to protect shareholders' capital or
(2) on a temporary basis for liquidity purposes or pending the investment of
proceeds from sales of Fund shares. The ability of the Fund to invest in
securities other than tax exempt bonds is limited by a requirement of the Code
that at least 50% of the Fund's total assets be invested in tax exempt
securities at the end of each calendar quarter. See "Income Dividends, Capital
Gain Distributions and Tax Status."
 
  The Municipal Bond Fund may purchase and sell portfolio investments to take
advantage of changes or anticipated changes in yield relationships, markets or
economic conditions. The Fund may also sell tax exempt bonds due to changes in
the adviser's evaluation of the issuer or cash needs resulting from redemption
requests for Fund shares. The secondary market for tax exempt bonds typically
has been less liquid than that for taxable debt securities, and this may
affect the Fund's ability to sell particular tax exempt bonds, especially in
periods when other investors are attempting to sell the same securities.
 
FOREIGN CURRENCY TRANSACTIONS
   
  Each of the Funds (except the Municipal Bond Fund) may invest in securities
of foreign issuers and may enter into forward foreign currency exchange
contracts, or buy or sell options on foreign currencies, in order to protect
against uncertainty in the level of future foreign exchange rates. Since
investment in securities of foreign issuers will usually involve currencies of
foreign countries, and since a Fund may temporarily hold funds in bank
deposits in foreign currencies during the course of investment programs, the
value of the assets of a Fund as measured in United States dollars may be
affected by changes in currency exchange rates and exchange control
regulations, and a Fund may incur costs in connection with conversion between
various currencies.     
 
  A Fund may enter into forward contracts under two circumstances. First, when
a Fund enters into a contract for the purchase or sale of a security
denominated or traded in a market in which settlement is made in a foreign
currency, it may desire to "lock in" the U.S. dollar price of the security. By
entering into a forward contract for the purchase or sale, for a fixed amount
of dollars, of the amount of foreign currency involved in the underlying
transactions, the Fund will be able to protect itself against a possible loss
resulting from an adverse change in the relationship between the U.S. dollar
and the subject foreign currency during the period between the date on which
the investment is purchased or sold and the date on which payment is made or
received.
 
  Second, when Loomis Sayles believes that the currency of a particular
country may suffer a substantial decline against another currency, it may
enter into a forward contract to sell, for a fixed amount of another currency,
the amount of the first currency approximating the value of some or all of the
Fund's portfolio investments denominated in the first currency. The precise
matching of the forward contract amounts and the value of the securities
involved will not generally be possible since the future value of such
securities in a currency will change as a consequence of market movements in
the value of those investments between the date the forward contract is
entered into and the date it matures.
 
  The Funds generally will not enter into forward contracts with a term of
greater than one year.
 
  Options on foreign currencies are similar to forward contracts, except that
one party to the option (the holder) is not contractually bound to buy or sell
the specified currency. Instead, the holder has discretion whether to
"exercise" the option and thereby require the other party to buy or sell the
currency on the terms specified in
 
                                       8
<PAGE>
 
the option. Options transactions involve transaction costs and, like forward
contract transactions, involve the risk that the other party may default on
its obligations (if the options are not traded on an established exchange) and
the risk that expected movements in the relative value of currencies may not
occur, resulting in an imperfect hedge or a loss to the Fund.
 
  Each Fund, in conjunction with its transactions in forward contracts,
options and futures (including the International Equity, Worldwide and Global
Bond Funds' transactions in options on securities described below), will
maintain in a segregated account with its custodian liquid assets with a
value, marked to market on a daily basis, sufficient to satisfy the Fund's
outstanding obligations under such contracts, options and futures.
 
OPTIONS
 
  As described in the Prospectus, each of the Funds, may for hedging purposes
or to enhance investment return, purchase and sell call and put options.
 
  An option entitles the holder to receive (in the case of a call option) or
to sell (in the case of a put option) a particular security at a specified
exercise price. An "American style" option allows exercise of the option at
any time during the term of the option. A "European style" option allows an
option to be exercised only at the end of its term. Options may be traded on
or off an established securities exchange.
 
  If the holder of an option wishes to terminate its position, it may seek to
effect a closing sale transaction by selling an option identical to the option
previously purchased. The effect of the purchase is that the previous option
position will be canceled. A Fund will realize a profit from closing out an
option if the price received for selling the offsetting position is more than
the premium paid to purchase the option; the Fund will realize a loss from
closing out an option transaction if the price received for selling the
offsetting option is less than the premium paid to purchase the option.
 
  The use of options involves risks. One risk arises because of the imperfect
correlation between movements in the price of options and movements in the
price of the securities that are the subject of the hedge. The Fund's hedging
strategies will not be fully effective if such imperfect correlation occurs.
 
  Price movement correlation may be distorted by illiquidity in the options
markets and the participation of speculators in such markets. If an
insufficient number of contracts are traded, commercial users may not deal in
options because they do not want to assume the risk that they may not be able
to close out their positions within a reasonable amount of time. In such
instances, options market prices may be driven by different forces than those
driving the market in the underlying securities, and price spreads between
these markets may widen. The participation of speculators in the market
enhances its liquidity. Nonetheless, the trading activities of speculators in
the options markets may create temporary price distortions unrelated to the
market in the underlying securities.
 
  An exchange-traded option may be closed out only on an exchange which
generally provides a liquid secondary market for an option of the same series.
If a liquid secondary market for an exchange-traded option does not exist, it
might not be possible to effect a closing transaction with respect to a
particular option, with the result that the Fund would have to exercise the
option in order to accomplish the desired hedge. Reasons for the absence of a
liquid secondary market on an exchange include the following: (i) there may be
insufficient trading interest in certain options; (ii) restrictions may be
imposed by an exchange on opening transactions or closing transactions or
both; (iii) trading halts, suspensions or other restrictions may be imposed
with respect to particular classes or series of options or underlying
securities; (iv) unusual or unforeseen circumstances may interrupt normal
operations on an exchange; (v) the facilities of an exchange or the Options
Clearing Corporation or other clearing organization may not at all times be
adequate to handle current trading volume; or (vi) one or more exchanges
could, for economic or other reasons, decide or be compelled at some future
date to discontinue the trading of options (or a particular class or series of
options), in which event the secondary market on that exchange (or in that
class or series of options) would cease to exist, although outstanding options
on that exchange that had been issued by the Options Clearing Corporation as a
result of trades on that exchange would continue to be exercisable in
accordance with their terms.
 
                                       9
<PAGE>
 
  The successful use of options depends in part on the ability of Loomis
Sayles to forecast correctly the direction and extent of interest rate, stock
price or currency value movements within a given time frame. To the extent
interest rates, stock prices or currency values move in a direction opposite
to that anticipated, the Fund may realize a loss on the hedging transaction
that is not fully or partially offset by an increase in the value of portfolio
securities. In addition, whether or not interest rates or the relevant stock
price or relevant currency values move during the period that the Fund holds
options positions, the Fund will pay the cost of taking those positions (i.e.,
brokerage costs). As a result of these factors, the Fund's total return for
such period may be less than if it had not engaged in the hedging transaction.
 
  An over-the-counter option (an option not traded on an established exchange)
may be closed out only with the other party to the original option
transaction. While the Fund will seek to enter into over-the-counter options
only with dealers who agree to or are expected to be capable of entering into
closing transactions with the Fund, there can be no assurance that the Fund
will be able to liquidate an over-the-counter option at a favorable price at
any time prior to its expiration. Accordingly, the Fund might have to exercise
an over-the-counter option it holds in order to achieve the intended hedge.
Over-the- counter options are not subject to the protections afforded
purchasers of listed options by the Options Clearing Corporation or other
clearing organization.
 
  The staff of the SEC has taken the position that over-the-counter options
should be treated as illiquid securities for purposes of each Fund's
investment restriction prohibiting it from investing more than 15% of its net
assets in illiquid securities. The Funds intend to comply with this position.
 
  Income earned by a Fund from its hedging activities will be treated as
capital gain and, if not offset by net recognized capital losses incurred by
the Fund, will be distributed to shareholders in taxable distributions.
Although gain from options transactions may hedge against a decline in the
value of a Fund's portfolio securities, that gain, to the extent not offset by
losses, will be distributed in light of certain tax considerations and will
constitute a distribution of that portion of the value preserved against
decline.
 
SMALL COMPANIES
 
  Investments in companies with relatively small capitalization may involve
greater risk than is usually associated with more established companies. These
companies often have limited product lines, markets or financial resources and
they may be dependent upon a relatively small management group. Their
securities may have limited marketability and may be subject to more abrupt or
erratic movements in price than securities of companies with larger
capitalization or market averages in general. The net asset values of funds
that invest in companies with smaller capitalization therefore may fluctuate
more widely than market averages.
 
                            MANAGEMENT OF THE TRUST
 
  The trustees and officers of the Trust and their principal occupations
during the past five years are as follows:
   
  EARL W. FOELL--Trustee. 380 Marlborough Street, #3, Boston, Massachusetts.
Retired; formerly Editor in-Chief, World Monitor Magazine and Editor-in-Chief,
The Christian Science Monitor.     
 
  RICHARD S. HOLWAY--Trustee. 1314 Seaspray Lane, Sanibel, Florida. Retired;
formerly, Vice President, Loomis Sayles. Director, Sandwich Cooperative Bank.
       
  MICHAEL T. MURRAY--Trustee. 404 N. Western Ave., Lake Forest, Illinois.
Retired; formerly, Vice President, Loomis Sayles.
 
  *DANIEL J. FUSS--President and Trustee. Executive Vice President and
Director, Loomis Sayles.
 
  SHEILA M. BARRY--Secretary and Compliance Officer. Assistant General Counsel
and Vice President, Loomis Sayles. Formerly, Senior Counsel and Vice
President, New England Funds, L.P.
 
                                      10
<PAGE>
 
  ROBERT J. BLANDING--Executive Vice President. 465 First Street West, Sonoma,
California. President, Chairman, Director and Chief Executive Officer, Loomis
Sayles.
 
  JAMES C. CARROLL--Vice President. 1533 N. Woodward, Bloomfield Hills,
Michigan. Vice President, Loomis Sayles. Formerly, Managing Director and
Senior Energy Analyst at Paine Webber, Inc.
 
  JEROME A. CASTELLINI--Vice President. Three 1st National Plaza, Chicago,
Illinois. Vice President and Director, Loomis Sayles.
   
  MARY C. CHAMPAGNE--Vice President. 1533 N. Woodward, Bloomfield Hills,
Michigan. Vice President, Loomis Sayles.     
- --------
* Trustee deemed an "interested person" of the Trust, as defined by the 1940
Act.
 
  E. JOHN DEBEER--Vice President. Vice President, Loomis Sayles.
 
  PAUL H. DREXLER--Vice President. Vice President, Loomis Sayles; formerly
Deputy Manager, Brown Brothers Harriman & Co.
 
  WILLIAM H. EIGEN, JR.--Vice President. Vice President, Loomis Sayles;
formerly Vice President, INVESCO Funds Group and Vice President, The Travelers
Corp.
 
  CHRISTOPHER R. ELY--Vice President. Vice President, Loomis Sayles; formerly
Senior Vice President and portfolio manager, Keystone Investment Management
Company, Inc.
 
  QUENTIN P. FAULKNER--Vice President. Vice President, Loomis Sayles.
 
  PHILIP C. FINE--Vice President. Vice President, Loomis Sayles; formerly Vice
President and portfolio manager, Keystone Investment Management Company, Inc.
 
  KATHLEEN C. GAFFNEY--Vice President, Vice President, Loomis Sayles.
   
  ISAAC GREEN--Vice President. 1533 N. Woodward, Bloomfield Hills, Michigan.
Vice President and Director, Loomis Sayles. [Formerly, Senior Vice President
and Director of Investments at NCM Capital Management Group.]     
 
  DEAN A. GULIS--Vice President. 1533 N. Woodward, Bloomfield Hills, Michigan.
Vice President, Loomis Sayles. Formerly, Principal and Director of Research at
Roney & Company.
 
  MARTHA F. HODGMAN--Vice President. Vice President, Loomis Sayles.
 
  MARK W. HOLLAND--Treasurer. Vice President--Finance and Administration and
Director, Loomis Sayles.
 
  JOHN HYLL--Vice President. 155 North Lake Avenue, Pasadena, California. Vice
President, Loomis Sayles.
 
  JEFFREY L. MEADE--Vice President. Executive Vice President, Chief Operating
Officer and Director, Loomis Sayles.
   
  PHILIP R. MURRAY--Assistant Treasurer, Vice President, Loomis Sayles.     
 
  KENT P. NEWMARK--Vice President. 555 California Street, San Francisco,
California. Vice President, Managing Partner and Director, Loomis Sayles.
 
  SCOTT S. PAPE--Vice President. Vice President, Loomis Sayles.
 
                                      11
<PAGE>
 
  JEFFREY C. PETHERICK--Vice President. 1533 N. Woodward, Bloomfield Hills,
Michigan. Vice President, Loomis Sayles.
 
  LAUREN B. PITALIS--Vice President. Vice President, Loomis Sayles; formerly
Vice President and Assistant Secretary of Harris Associates Investment Trust.
 
  PHILIP J. SCHETTEWI--Vice President. Vice President and Director, Loomis
Sayles.
 
  DAVID L. SMITH--Vice President. Vice President, Loomis Sayles; formerly Vice
President and portfolio manager, Keystone Investment Management Company, Inc.
 
  SANDRA P. TICHENOR--Vice President. 465 First Street West, Sonoma,
California. General Counsel, Vice President, Secretary and Clerk, Loomis
Sayles. Formerly, Partner, Heller, Ehrman, White & McAuliffe.
 
  JEFFREY W. WARDLOW--Vice President. 1533 N. Woodward, Bloomfield Hills,
Michigan. Vice President, Loomis Sayles.
 
  GREGG D. WATKINS--Vice President. Vice President, Loomis Sayles.
 
  ANTHONY J. WILKINS--Vice President. Vice President and Director, Loomis
Sayles.
 
  JOHN F. YEAGER III--Vice President. Vice President, Loomis Sayles; formerly
Vice President--Marketing, INVESCO Funds Group and Assistant Comptroller,
INVESCO Capital Management.
 
  Previous positions during the past five years with Loomis Sayles are
omitted, if not materially different.
 
  Except as indicated above, the address of each trustee and officer of the
Trust affiliated with Loomis Sayles is One Financial Center, Boston,
Massachusetts. The Trust pays no compensation to its officers or to the
trustees listed above who are directors, officers or employees of Loomis
Sayles. Each trustee who is not a director, officer or employee of Loomis
Sayles is compensated at the rate of $1,250 per fund per annum.
 
                                      12
<PAGE>
 
                              COMPENSATION TABLE
                  
               FOR THE NINE MONTHS ENDED SEPTEMBER 30, 1998     
 
<TABLE>   
<CAPTION>
                                                                              (5)
                                                                             TOTAL
                                               (3)              (4)       COMPENSATION
                              (2)          PENSION OR        ESTIMATED   FROM TRUST AND
          (1)              AGGREGATE   RETIREMENT BENEFITS    ANNUAL     FUND COMPLEX*
    NAME OF PERSON,       COMPENSATION ACCRUED AS PART OF  BENEFITS UPON    PAID TO
        POSITION           FROM TRUST     FUND EXPENSES     RETIREMENT      TRUSTEE
    ---------------       ------------ ------------------- ------------- --------------
<S>                       <C>          <C>                 <C>           <C>
Earl W. Foell, Trustee..   $                   N/A              N/A        $
Richard S. Holway,
 Trustee................   $                   N/A              N/A        $
Terry R. Lautenbach**,
 Trustee................   $                   N/A              N/A        $
Michael T. Murray,
 Trustee................   $                   N/A              N/A        $
</TABLE>    
- --------
*  No Trustee receives any compensation from any mutual funds affiliated with
   Loomis Sayles, other than the Trust.
   
** Mr. Lautenbach retired from the Board of Trustees on October 26, 1998.     
       
    
  As of September 30, 1998, the officers and trustees of the Trust owned
beneficially shares of each Fund as follows: 427,495.680 shares of the Bond
Fund, 18,173.581 shares of the Core Value Fund, 26,813.759 shares of the
Global Bond Fund, 16,668.673 shares of the Growth Fund, 272,926.72 shares of
the High Yield Fund, 18,468.166 shares of the International Equity Fund,
11,473.108 shares of the Investment Grade Bond Fund, 1,239.933 of the Mid-Cap
Value Fund, 69,218.193 shares of the Municipal Bond Fund, 65,428.296 shares of
the Short-Term Bond Fund, 2,742.817 shares of the Small Cap Growth Fund,
37,257.122 shares of the Small Cap Value Fund, 1,480.432 of the Strategic
Value Fund, 13,501.622 shares of the U.S. Government Securities Fund, and
15,647.889 shares of the Worldwide Fund. These amounts include shares held by
the Loomis Sayles Employees' Profit Sharing Plan (the "Profit Sharing Plan")
for the accounts of officers and trustees of the Trust, but exclude all other
holdings of the Profit Sharing Plan and the Loomis-Sayles Funded Pension Plan
(the "Pension Plan"). As of September 30, 1998, the Pension Plan owned the
following percentages of the outstanding Institutional Class shares of the
indicated Funds: 0.06% of the Bond Fund, 9.24% of the Core Value Fund, 21.12%
of the Global Bond Fund, 6.33% of the Growth Fund, 34.06% of the Intermediate
Maturity Bond Fund, 15.69% of the International Equity Fund, 0.11% of the Short
Term Bond Fund, 13.18% of the Small Cap Growth Fund, 0.71% of the Small Cap
Value Fund, 28.98% of the U.S. Government Securities Fund, and 80.98% of the
Worldwide Fund. As of September 30, 1998, the Profit Sharing Plan owned the
following percentages of the outstanding Institutional Class shares of the
indicated Funds: 0.08% of the Bond Fund, 12.14% of the Core Value Fund, 7.02% of
the Global Bond Fund, 32.58% of the Growth Fund, 18.19% of the High Yield Fund,
14.92% of the Intermediate Maturity Bond Fund, 6.42% of the International Equity
Fund, 12.39% of the Investment Grade Bond Fund, 78.73% of the Mid-Cap Growth
Fund, 39.83% of the Mid-Cap Value Fund, 11.43% of the Short-Term Bond Fund,
13.47% of the Small Cap Growth Fund, 3.95% of the Small Cap Value Fund, 62.65%
of the Strategic Value Fund, 20.27% of the U.S. Government Securities Fund, and
12.41% of the Worldwide Fund. The trustee of the Pension Plan is Fleet
Investment Management. The Pension Plan's Advisory Committee, which is composed
of the same individuals listed below as trustees of the Profit Sharing Plan, has
the sole voting and investment power with respect to the Pension Plan's shares.
The trustees of the Profit Sharing Plan are E. John deBeer, Quentin P. Faulkner,
Sandra P. Tichenor, Larry K. Shaw, Kathleen C. Gaffney, Mark W. Holland, and
Patrick P. Hurley, all of whom are officers and employees of Loomis Sayles and
(except for Messrs. Hurley and Shaw) trustees or officers of the Trust. Plan
participants are entitled to exercise investment and voting power over shares
owned of record by the Profit Sharing Plan. Shares not voted by participants are
voted in the same proportion as the shares voted by the voting participants. The
address for the Profit Sharing Plan and the Pension Plan is One Financial
Center, Boston, Massachusetts. At the date of this Statement of Additional
Information, no officer or trustee, and as of October 31, 1998, except as noted
below, no person, owns more than 5% of the outstanding shares of any Fund.     
 
                                      13
<PAGE>
 
                           INSTITUTIONAL CLASS SHARES
<TABLE>   
<CAPTION>
                                                                   PERCENTAGE OF
SHAREHOLDER                       ADDRESS                           SHARES HELD
- -----------                       -------                          -------------
 
BOND FUND
<S>                               <C>                              <C>
Charles Schwab & Co. Inc.         101 Montgomery St.                   40.72%
                                  San Francisco, CA 94104

Charles Schwab & Co. Inc.         101 Montgomery St.                    8.73%
                                  San Francisco, CA 94104
 
CORE VALUE FUND
 
Charles Schwab & Co. Inc.         101 Montgomery St.                   22.64%
                                  San Francisco, CA 94104

John W. George, Trustee           590 Renaud                            5.88%
John W. George Trust              Grosse Pointe, MI 48236
U/A/D 12/6/90

Asbestos Workers Local            C/O Loomis Sayles & Co. Inc.          6.41%
#84 Pension Fund                  1593 North Woodward, Ste 300
                                  Bloomfield Hills, MI 48304

First Trust NA Trustee            P.O. Box 64010                        7.29%
Green Tree Financial Corp         St. Paul, MN 55164
401K Plan
 
GLOBAL BOND FUND
 
San Diego Transit Pension Plan    P.O. Box 2511                         9.54%
                                  San Diego, CA 92112

Northwest Bank MN NA              P.O. Box 1450 NW 8477                18.64%
C/F Desert States UFCW Union      Minneapolis, MN 55480
Employees Pension AC#1327982D

Fleet National Bank TTEE          P.O. Box 92800                       15.92%
Kaman Corp Master Trust Fixed     Rochester, NY 14692
Income Fund U/A/D 10-1-96
Attn A/C# 0004884410

Charles Schwab & Co. Inc.         101 Montgomery St.                   38.58%
                                  San Francisco, CA 94104
 
GROWTH FUND
 
Fiduciary Trust Co. Cust          P.O. Box 3199                         6.33%
FBO Scott R. Shoemaker            Church St. Station
                                  New York, NY 10008

Fiduciary Trust Co. Cust          P.O. Box 3199                         5.58%
FBO Charles Grant Shoemaker       Church St. Station
                                  New York, NY 10048
 
HIGH YIELD FUND
 
Daniel J. Fuss                    44 Longfellow Road                   32.38%
                                  Wellesley, MA 02181

Charles Schwab & Co. Inc.         101 Montgomery St.                   30.29%
</TABLE>    
 
                                       14
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                    PERCENTAGE OF
SHAREHOLDER                       ADDRESS                            SHARES HELD
- -----------                       -------                           -------------
<S>                               <C>                               <C>
                                  San Francisco, CA 94104
Rosemary B. Fuss                  44 Longfellow Road                    12.06%
                                  Wellesley, MA 02181
 
INTERMEDIATE MATURITY BOND FUND
 
Charles Schwab & Co. Inc.         101 Montgomery St.                    52.48%
                                  San Francisco, CA 94104

Hawaii Sheet Metal Workers        1405 N. King St. Rm 403               28.00%
Health & Welfare Fund             Honolulu, HI 96817
Pomona College                    Alexander Hall                         7.95%
                                  550 N. College Ave.
                                  Claremont, CA 91711
 
INTERNATIONAL EQUITY FUND
 
Charles Schwab & Co. Inc.         101 Montgomery St.                    22.13%
                                  San Francisco, CA 94104

Comerica Bank FBO                 P.O. Box 75000 MC 3446                11.95%
City of Livonia Employee          Detroit, MI 48275
Retirement System A/C 82150B

The Security Mutual Life          200 Centennial Mall North              6.99%
Insurance Co. of                  P.O. Box 82248
Lincoln Nebraska                  Lincoln, NE 68501
 
INVESTMENT GRADE BOND FUND
 
Loomis Sayles & Company,
 L.P.                             Attn: Paul Sherba                     43.92%
                                  One Financial Center
                                  Boston, MA 02111

Charles Schwab & Co. Inc.         101 Montgomery St.                    21.57%
                                  San Francisco, CA 94104

Pomona College                    Alexander Hall                         7.23%
                                  550 N. College Ave.
                                  Claremont, CA 91711
 
MID-CAP GROWTH FUND
 
Charles Schwab & Co. Inc.         101 Montgomery St.                    82.15%
                                  San Francisco, CA 94104

American National Bank            120 So. LaSalle St.                    9.77%
Howard Siegel or Catherine        Chicago, IL 60603
Siegel Trust
 
MID-CAP VALUE FUND
 
Charles Schwab & Co. Inc.         101 Montgomery St.                    41.61%
                                  San Francisco, CA 94104
</TABLE>    
 
                                       15
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                      PERCENTAGE OF
SHAREHOLDER                        ADDRESS                             SHARES HELD
- -----------                        -------                            -------------
<S>                                <C>                                <C>
John W. George, Jr. Trustee        590 Renaud                              8.10%
John W. George, Jr. Trust          Grosse Pointe, MI 48236
U/A/D 12/6/90

Carey & Co.                        P.O. Box 1558                           8.04%
C/O Huntington National Bank       Columbus, OH 43260
Attn: Mutual Funds HC1024
 
MUNICIPAL BOND FUND
 
John W. George Jr. Trustee         590 Renaud                             19.57%
John W. George Jr. Trust           Grosse Pointe, MI 48236
U/A/D 12/6/90

Ann A. Morris Trustee              General Delivery                       13.90%
Ann A. Morris Trust                Lummi Island, WA 98262
 
SHORT-TERM BOND FUND
 
Charles Schwab & Co. Inc.          101 Montgomery St.                     21.30%
                                   San Francisco, CA 94104

George R. Rodrigues, Jr.           1109 Bethel St. Ste. 403                7.92%
Herbert S K Kaopua Sr TTEES        Honolulu, HI 96813
Pamcah-UA Local 675
Health & Welfare DTD 9/1/61

John W. George Jr. Trustee         590 Renaud                              6.51%
John W. George Jr. Trust           Grosse Pointe, MI 48236
U/A/D 12/6/90

NFSC FEBO #179-257206              54 Jemez Canyon Road                   14.63%
Santa Ana Non-Profit

 Enterprise                        Box 9201
                                   Bernalillo, NM 87004
 
SMALL CAP GROWTH FUND
 
Charles Schwab & Co. Inc.          101 Montgomery St.                     32.65%
                                   San Francisco, CA 94104

The Community Foundation           456 King St.                           12.59%
Serving Coastal SC                 Charleston, SC 29403

Donaldson Lufkin Jenrette          P.O. Box 2052                           8.32%
Securities Corporation             Jersey City, NJ 07303

Trussal & Co.                      P. O. Box 771072                        6.77%
                                   Detroit, MI 48277

Fifth Third Bank, Trustee          P.O. Box 630074                         6.51%
Catholic Community
 Foundation                        Cincinnati, OH 45263

Covie & Co.                        5101 N. Francisco Ave.                  6.43%
C/O Covenant Trust Co.             Chicago, IL 60625
Carey & Co.                        P.O. Box 1558                           6.28%
</TABLE>    
 
                                       16
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                     PERCENTAGE OF
SHAREHOLDER                       ADDRESS                             SHARES HELD
- -----------                       -------                            -------------
<S>                               <C>                                <C>
                                  Columbus, OH 43216
 
SMALL CAP VALUE FUND
 
Charles Schwab & Co. Inc.         101 Montgomery St.                     12.41%
                                  San Francisco, CA 94104

Smith Barney Inc.                 333 West 34th St.; 7th Fl.             11.95%
Book Entry Account                New York, NY 10001
 
STRATEGIC VALUE FUND
 
Charles Schwab & Co. Inc.         101 Montgomery St.                     79.16%
                                  San Francisco, CA 94104

Pomona College                    Alexander Hall                         11.02%
                                  550 N. College Ave.
                                  Claremont, CA 91711
 
U.S. GOVERNMENT SECURITIES FUND
 
Charles Schwab & Co. Inc.         101 Montgomery St.                     68.30%
                                  San Francisco, CA 94104
 
WORLDWIDE FUND
 
Charles Schwab & Co. Inc.         101 Montgomery St.                     94.84%
                                  San Francisco, CA 94104
</TABLE>    
 
                                       17
<PAGE>
 
                               
                            RETAIL CLASS SHARES     
 
<TABLE>   
<CAPTION>
                                                                  PERCENTAGE OF
SHAREHOLDER                                   ADDRESS              SHARES HELD
- -----------                                   -------             -------------
<S>                                   <C>                         <C>
BOND FUND
Reliance Trust Co.                    P.O. Box 48449                   6.09
FBO Clear Channel Comm                Atlanta, GA 30362-1449
401K

CORE VALUE FUND

Charles Schwab & Co. Inc.             101 Montgomery St.              34.15%
                                      San Francisco, CA 94104

Jupiter & Co.                         P.O. Box 9130                   30.11%
C/O Investors Bank & Trust            Boston, MA

NFSC FEBO                             2651 Sleepy Hollow Dr.           7.52%
Stephen M. Keil                       State College, PA 16803

GLOBAL BOND FUND

Charles Schwab & Co. Inc.             101 Montgomery St.              48.00%
Attn. Mutual Fund Dept.               San Francisco, CA 94104

Southwest Securities, Inc.            P.O. Box 509002                 16.05%
FBO First National Bank Edinburg      Dallas, TX 75250

GROWTH FUND
Angelo V. Glorioso                    225 Summit Dr.                  53.34%
                                      Pittsburgh, PA 15238

Charles Schwab & Co. Inc.             101 Montgomery St.              25.88%
Attn. Mutual Fund Dept.               San Francisco, CA 94104

NFSC FEBO                             900 Palisade Ave.               14.49%
FMT CO CUST IRA Rollover              Fort Lee, NJ 07024
Leslie G. Brady

HIGH YIELD FUND

Charles Schwab & Co. Inc.             101 Montgomery St.              33.96%
                                      San Francisco, CA 94104

Charles Schwab & Co. Inc.             101 Montgomery St.              17.12%
                                      San Francisco, CA 94104

METLIFE Defined Contribution Group    72 Eagle Rock Ave.               6.75%
Attn: Peter Hall                      East Hanover, NJ 07936
</TABLE>    
 
                                       18
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                 PERCENTAGE OF
SHAREHOLDER                                  ADDRESS              SHARES HELD
- -----------                                  -------             -------------
 
INTERMEDIATE MATURITY BOND FUND
<S>                                 <C>                          <C>
Charles Schwab & Co. Inc.           101 Montgomery St.               89.10%
                                    San Francisco, CA 94104
 
INTERNATIONAL EQUITY FUND
 
James Goodman                       1400 Ocean Blvd. Apt. 706N       50.80%
Dorothy Goodman JT TEN              Boca Raton, FL 33432

CIBC Oppenheimer Corp.              P.O. Box 3484                    16.44%
FBO 371-11893-10                    Church St. Station               
                                    New York, NY 10008               
                                                                     
CIBC Oppenheimer Corp.              P.O. Box 3484                    12.05%
                                    Church St. Station               
                                    New York, NY 10008               
                                                                     
CIBC Oppenheimer Corp.              P.O. Box 3484                     9.04%
FBO 371-11726-13                    Church St. Station
                                    New York, NY 10008

Charles Schwab & Co. Inc.           101 Montgomery St.                8.97%
                                    San Francisco, CA 94104

Saxon & Co.                         P.O. Box 7780-1888                6.78%
FBO Boes Anna Marie Ilita           Philadelphia, PA 19182

NFSC FEBO #x08-233420               P.O. Box 750633                   5.96%
Bawa N. Mallick                     Forest Hills, NY 11375

CIBC Oppenheimer Corp.              P.O. Box 3484                     5.68%
FBO 324-63220-14                    Church St. Station
                                    New York, NY 10008

CIBC Oppenheimer Corp.              P.O. Box 3484                     5.59%
FBO 371-11854-17                    Church St. Station
                                    New York, NY 10008

CIBC Oppenheimer Corp.              P.O. Box 3484                     5.34%
FBO 392-14139-14                    Church St. Station
                                    New York, NY 10008

CIBC Oppenheimer Corp.              P.O. Box 3484                     5.08%
FBO 324-22271-18                    Church St. Station
                                    New York, NY 10008
 
INVESTMENT GRADE BOND FUND
 
Charles Schwab & Co. Inc.           101 Montgomery St.               35.46%
                                    San Francisco, CA 94104

Charles Schwab & Co. Inc.           101 Montgomery St.                5.82%
                                    San Francisco, CA 94104

NFSC FEBO #157-197300               4 Buxton Lane                     5.45%
FBO George D. Dugan                 Riverside, CT 06878

NFSC FEBO #z11-056570               4545 SW 97th Terrace              5.36%
Sappington Revocable Living Trust   Gainesville, FL 32608
</TABLE>    
 
                                       19
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                  PERCENTAGE OF
SHAREHOLDER                                 ADDRESS                SHARES HELD
- -----------                                 -------               -------------
 
MID-CAP GROWTH FUND
<S>                                <C>                            <C>
Jane F. Clark                      140 Enid Ln                        72.78%
                                   Northfield, IL 60093

Charles Schwab & Co. Inc.          101 Montgomery St.                 12.67%
                                   San Francisco, CA 94104

NFSC FEBO #127-599832              306 Hackensack St.                  8.13%
FBO Santo J. Pittsman              Wood Ridge, NJ 07075
 
MID-CAP VALUE FUND
 
Charles Schwab & Co. Inc.          101 Montgomery St.                 59.14%
                                   San Francisco, CA 94104

Donaldson Lufkin Jenrette          One Pershing Plaza--7th Fl         25.15%
Securities Corporation Inc.        Jersey City, 07303
 
SHORT-TERM BOND FUND
 
Charles Schwab & Co. Inc.          101 Montgomery St.                 45.97%
                                   San Francisco, CA 94104

Donaldson Lufkin Jenrette          P.O. Box 2052                      12.56%
Securities Corporation Inc.        Jersey City, 07303

Charles Schwab & Co. Inc.          101 Montgomery St.                  8.20%
                                   San Francisco, CA 94104

NFSC FEBO #201-528218              245 Tower Rd.                       8.10%
FBO Carmine A. Greco               Lincoln, MA 01773

Donaldson Lufkin Jenrette          P.O. Box 2052                       5.93%
Securities Corporation Inc.        Jersey City, 07303

State Street Bank & Trust Co.      405 S. Yucca Dr.                    5.83%
C/F The IRA of                     Wickenburg, AZ 85390
Roger E. Wakefield
 
SMALL CAP GROWTH FUND
 
Charles Schwab & Co. Inc.          101 Montgomery St.                 51.44%
                                   San Francisco, CA 94104

MO Institute of Sports Medicine    621 New Ballas                     32.79%
Profit Sharing Plan & Trust        Suite 101
DTD 5/1/80                         St. Louis, MO 63141
 
SMALL CAP VALUE FUND
 
Charles Schwab & Co. Inc.          101 Montgomery St.                 33.74%
                                   San Francisco, CA 94104
</TABLE>    
 
                                       20
<PAGE>
 
<TABLE>   
<CAPTION>
                                                                 PERCENTAGE OF
SHAREHOLDER                                  ADDRESS              SHARES HELD
- -----------                                  -------             -------------
<S>                                <C>                           <C>
First Trust National Association   180 East Fifth St.                20.63%
Trustee for United Healthcare      P.O. Box 64488
401K Savings Plan                  St. Paul, MN 55164

Chase Manhattan Bank Trustee       770 Broadway                      19.41%
Metlife Defined Contribution       10th Floor
Group; Attn: Cindy Chu             New York, NY 10003
 
STRATEGIC VALUE FUND
 
Lazard Freres & Co. LLC            30 Rockefeller Plaza              95.75%
FBO Catholic Cemetaries            60th Floor
                                   New York, New York
 
WORLDWIDE FUND
 
Donaldson Lufkin Jenrette          P.O. Box 2052                     30.85%
Securities Corporation Inc.        Jersey City, 07303

State Street Bank &Trust Co.       235 Arlington Road Apt. 214       28.44%
Custodian for the IRA of           Redwood City, CA 94062
Benjamin T. Ream

Charles Schwab & Co. Inc.          101 Montgomery St.                18.42%
                                   San Francisco, CA 94104

National Investor Services         55 Water St.                       9.77%
Corp.                              New York, NY 10041
FBO Our Customers
Mutual Funds Dept. 32nd Floor

Donaldson Lufkin Jenrette          P.O. Box 2052                      6.17%
Securities Corporation Inc.        Jersey City, 07303
</TABLE>    
 
                                       21
<PAGE>
 
                               
                            ADMIN CLASS SHARES     
 
<TABLE>   
<CAPTION>
                                                                    PERCENTAGE OF
SHAREHOLDER                                 ADDRESS                  SHARES HELD
- -----------                                 -------                 -------------
<S>                                 <C>                             <C>
BOND FUND
Smith Barney Corp. Trust            Two Tower Center                    99.98%
Smith Barney 401k Adviser           P.O. Box 1063
Group Trust                         E. Brunswick, NJ 08816
                                    San Francisco, CA 94104
 
SMALL CAP VALUE FUND
 
Smith Barney Corp. Trust            Two Tower Center                    67.87%
Smith Barney 401k Adviser           P.O. Box 1063
Group Trust                         E. Brunswick, NJ 08816
                                    San Francisco, CA 94104

Merrill Lynch Trust Co.             265 Davidson Ave.                   28.60%
FBO Qualified Retirement       
Plans                               Somerset NJ 08873
</TABLE>    

   
  To the extent any of the shareholders listed above beneficially owns more
than 25% of a Fund, it may be deemed to "control" such Fund.     
 
                                       22
<PAGE>
 
                    INVESTMENT ADVISORY AND OTHER SERVICES
   
  Advisory Agreements. Loomis Sayles serves as investment adviser under a
separate advisory agreement relating to each of the Bond and High Yield Funds,
each dated August 30, 1996, relating to the Growth, Core Value, Small Cap
Value, International Equity, Worldwide, Global Bond, U.S. Government
Securities, Municipal Bond and Short-Term Bond Funds, each dated August 30,
1996, as amended January 1, 1997, and relating to each of the Small Cap
Growth, Mid-Cap Value, Mid-Cap Growth, Strategic Value, Investment Grade Bond,
and Intermediate Maturity Bond Funds, each dated December 1, 1996. The
advisory agreements relating to each of the Growth, Core Value, Small Cap
Value, International Equity, Worldwide, Global Bond, U.S. Government
Securities, Municipal Bond and Short-Term Bond Funds were amended effective
January 1, 1997, and December 1, 1998, for U.S. Government Securities Fund,
solely for the purpose of reducing the fees payable thereunder. Under each
advisory agreement, Loomis Sayles manages the investment and reinvestment of
the assets of the relevant Fund and generally administers its affairs, subject
to supervision by the board of trustees of the Trust. Loomis Sayles furnishes,
at its own expense, all necessary office space, facilities and equipment,
services of executive and other personnel of the Fund and certain
administrative services. For these services, the advisory agreements provide
that each Fund shall pay Loomis Sayles a monthly investment advisory fee at
the following annual percentage rates of the particular Fund's average daily
net assets:     
 
<TABLE>   
<CAPTION>
      FUND                                                                 RATE
      ----                                                                 ----
      <S>                                                                  <C>
      Growth.............................................................. .50%
      Core Value.......................................................... .50
      Small Cap Value..................................................... .75
      International Equity................................................ .75
      Worldwide........................................................... .75
      Small Cap Growth.................................................... .75
      Mid-Cap Value....................................................... .75
      Mid-Cap Growth...................................................... .75
      Strategic Value..................................................... .50
      Bond................................................................ .60
      High Yield.......................................................... .60
      Global Bond......................................................... .60
      U.S. Government Securities.......................................... .30
      Municipal Bond...................................................... .40
      Short-Term Bond..................................................... .25
      Investment Grade Bond............................................... .40
      Intermediate Maturity Bond.......................................... .40
</TABLE>    
   
  During the periods shown below, pursuant to the advisory agreements
described above and advisory agreements in effect prior to January 1, 1997
under which fees were payable to Loomis Sayles at the following annual rates
by the indicated Funds (expressed as a percentage of average daily net
assets): Growth, 0.75%; Core Value, 0.75%; International Equity, 1.00%; Small
Cap Value, 1.00%; Bond, 0.60%; Global Bond, 0.75%; Municipal Bond, 0.60%;
Short Term Bond, 0.50%; Worldwide, 0.75%; High Yield, 0.60%, Loomis Sayles
received the following amount of investment advisory fees from each Fund
(before voluntary fee reductions and expense assumptions) and bore the
following amounts of fee reductions and expense assumptions for each Fund:    
   
  During the periods shown below, pursuant to the advisory agreement described
above and the advisory agreements in effect prior to January 1, 1997, and
December 1, 1998, respectively, under which fees were payable to Loomis Sayles
at the annual rates of 0.60% prior to January 1, 1997, and the annual rate of
0.40% prior to December 1, 1998, by the U.S. Government Securities Fund.     
 
                                      23
<PAGE>
 
<TABLE>   
<CAPTION>
                         FISCAL YEAR ENDED 12/31/96    FISCAL YEAR ENDED 12/31/97    NINE MONTHS ENDED 9/30/98*
                         ----------------------------- ----------------------------- -----------------------------
                                         FEE WAIVERS                   FEE WAIVERS                   FEE WAIVERS
                           ADVISORY      AND EXPENSE     ADVISORY      AND EXPENSE     ADVISORY      AND EXPENSE
        FUND                 FEES        ASSUMPTIONS       FEES        ASSUMPTIONS       FEES        ASSUMPTIONS
        ----             -------------- -------------- -------------- -------------- -------------- --------------
<S>                      <C>            <C>            <C>            <C>            <C>            <C>
Growth.................. $      318,602  $          0  $      174,976  $     74,929     $   114,917    $   52,384
Core Value..............        297,001             0         269,200        29,404         264,693        12,673
Small Cap Value.........      1,125,160             0       1,581,667        12,741       1,981,662         5,254
International Equity....        848,205             0         705,111       178,102         451,871       124,877
Worldwide...............         23,335        84,635          55,489       148,392          32,580       112,466
Small Cap Growth**......            N/A           N/A          24,894       170,503          67,049       117,517
Mid-Cap Value**.........            N/A           N/A          18,691       158,363          23,688       117,826
Mid-Cap Growth**........            N/A           N/A          11,993       151,104          11,818       109,517
Strategic Value**.......            N/A           N/A           4,385       144,233           5,321       114,273
Bond....................      2,205,461             0       5,460,675       197,170       6,920,645       112,593
Global Bond.............        119,648        43,855         178,622       123,445         155,995        85,930
US. Government
 Securities.............        130,189        40,922          55,096        87,078          65,031        60,872
Municipal Bond..........         48,518       105,784          34,082       102,318          28,142        77,070
Short-Term Bond.........        100,693        34,987          41,211       143,266          45,845        74,443
High Yield..............          2,544        47,964          34,062       185,981          50,667       141,220
Investment Grade
 Bond**.................            N/A           N/A           8,585       162,568          12,300       119,899
Intermediate Maturity
 Bond**.................            N/A           N/A          17,125       147,955          25,473       122,162
</TABLE>    
- --------
   
 * The fiscal year-end for each of the Funds has changed to September 30.     
   
** The Small Cap Growth, Mid-Cap Value, Mid-Cap Growth, Strategic Value,
   Investment Grade Bond and Intermediate Maturity Bond Funds commenced
   investment operations on January 2, 1997.     
 
  The Trust pays the compensation of its trustees who are not directors,
officers or employees of Loomis Sayles or its affiliates (other than
registered investment companies); registration, filing and other fees in
connection with requirements of regulatory authorities; all charges and
expenses of its custodian and transfer agent; the charges and expenses of its
independent accountants; all brokerage commissions and transfer taxes in
connection with portfolio transactions; all taxes and fees payable to
governmental agencies; the cost of any certificates representing shares of the
Funds; the expenses of meetings of the shareholders and trustees of the Trust;
the charges and expenses of the Trust's legal counsel; interest on any
borrowings by the Funds; the cost of services, including services of counsel,
required in connection with the preparation of, and the cost of printing, the
Trust's registration statements and prospectuses, including amendments and
revisions thereto, annual, semiannual and other periodic reports of the Trust,
and notices and proxy solicitation material furnished to shareholders or
regulatory authorities, to the extent that any such materials relate to the
Trust or its shareholders; and the Trust's expenses of bookkeeping,
accounting, auditing and financial reporting, including related clerical
expenses.
 
  Under each advisory agreement, if the total ordinary business expenses of a
Fund or the Trust as a whole for any fiscal year exceed the lowest applicable
limitation (based on percentage of average net assets or income) prescribed by
any state in which the shares of the Fund or the Trust are qualified for sale,
Loomis Sayles shall pay such excess. Loomis Sayles will not be required to
reduce its fee or pay such expenses to an extent or under circumstances which
would result in any Fund's inability to qualify as a regulated investment
company under the Code. The term "expenses" is defined in the advisory
agreements or in relevant state regulations and excludes brokerage
commissions, taxes, interest, distribution-related expenses and extraordinary
expenses.
 
  As described in the Prospectus, Loomis Sayles has agreed to certain
additional, voluntary arrangements to limit Fund expenses. These arrangements
may be modified or terminated by Loomis Sayles at any time.
 
  Each advisory agreement provides that it will continue in effect for two
years from its date of execution and thereafter from year to year if its
continuance is approved at least annually (i) by the Board of Trustees of the
Trust or by vote of a majority of the outstanding voting securities of the
relevant Fund and (ii) by vote of a
 
                                      24
<PAGE>
 
majority of the Trustees who are not "interested persons" of the Trust, as
that term is defined in the 1940 Act, cast in person at a meeting called for
the purpose of voting on such approval. Any amendment to an advisory agreement
must be approved by vote of a majority of the outstanding voting securities of
the relevant Fund and by vote of a majority of the Trustees who are not such
interested persons, cast in person at a meeting called for the purpose of
voting on such approval. Each agreement may be terminated without penalty by
vote of the Board of Trustees or by vote of a majority of the outstanding
voting securities of the relevant Fund, upon sixty days' written notice, or by
Loomis Sayles upon ninety days' written notice, and each terminates
automatically in the event of its assignment. In addition, each agreement will
automatically terminate if the Trust or the Fund shall at any time be required
by Loomis Sayles to eliminate all reference to the words "Loomis" and "Sayles"
in the name of the Trust or the Fund, unless the continuance of the agreement
after such change of name is approved by a majority of the outstanding voting
securities of the relevant Fund and by a majority of the Trustees who are not
interested persons of the Trust or Loomis Sayles.
 
  Each advisory agreement provides that Loomis Sayles shall not be subject to
any liability in connection with the performance of its services thereunder in
the absence of willful misfeasance, bad faith, gross negligence or reckless
disregard of its obligations and duties.
 
  Loomis Sayles acts as investment adviser or subadviser to New England Value
Fund, New England Strategic Income Fund, New England Star Advisers Fund; New
England Star Small Cap Fund and New England Balanced Fund, which are series of
New England Funds Trust I, a registered open- end management investment
company, New England High Income Fund, a series of New England Fund Trust II,
a registered, open-end management investment company, New England Equity
Income Fund, a series of New England Funds Trust III, a registered open-end
management investment company, and to the Balanced Series and the Small Cap
Series of New England Zenith Fund, which is also a registered open-end
management investment company, as well as to Loomis Sayles Investment Trust,
also a registered open-end management investment company. Loomis Sayles also
provides investment advice to certain other open-end management investment
companies and numerous other corporate and fiduciary clients.
 
  The general partner of Loomis Sayles is a special purpose corporation that
is an indirect wholly-owned subsidiary of Nvest Companies, L.P. ("Nvest
Companies"). Nvest Companies' managing general partner, Nvest Corporation, is
a direct wholly-owned subsidiary of Metropolitan Life Insurance Company ("Met
Life"), a mutual life insurance company. Nvest Companies' advising general
partner, Nvest L.P., is a publicly traded company listed on the New York Stock
Exchange. Nvest Corporation is the sole general partner of Nvest L.P.
 
  Certain officers and trustees of the Trust also serve as officers, directors
and trustees of other investment companies and clients advised by Loomis
Sayles. The other investment companies and clients sometimes invest in
securities in which the Funds also invest. If a Fund and such other investment
companies or clients desire to buy or sell the same portfolio securities at
the same time, purchases and sales may be allocated, to the extent
practicable, on a pro rata basis in proportion to the amounts desired to be
purchased or sold for each. It is recognized that in some cases the practices
described in this paragraph could have a detrimental effect on the price or
amount of the securities which a Fund purchases or sells. In other cases,
however, it is believed that these practices may benefit the Funds. It is the
opinion of the trustees that the desirability of retaining Loomis Sayles as
adviser for the Funds outweighs the disadvantages, if any, which might result
from these practices.
 
  Distribution Agreement and Rule 12b-1 Plans. Under an agreement with the
Trust (the "Distribution Agreement"), Loomis Sayles Distributors, L.P. serves
as the general distributor of each class of shares of the Funds. Under this
agreement, Loomis Sayles Distributors, L.P. is not obligated to sell a
specific number of shares. Loomis Sayles Distributors, L.P. bears the cost of
making information about the Funds available through advertising and other
means and the cost of printing and mailing prospectuses to persons other than
shareholders. The Funds pay the cost of registering and qualifying their
shares under state and federal securities laws and the distribution of
prospectuses to existing shareholders.
 
  As described in the Prospectuses, the Funds (other than the U.S. Government
Securities and Municipal Bond Funds) have adopted Rule 12b-1 plans ("Plans")
for their Retail Class shares. The Bond and Small Cap Value
 
                                      25
<PAGE>
 
Funds have adopted Plans for their Admin Class shares. The Plans, among other
things, permit the relevant classes of the Funds to pay the Funds' distributor
(currently Loomis Sayles Distributors, L.P.) monthly fees, at annual rates not
exceeding 0.25% of the assets of the Retail Class and Admin Class
respectively. Pursuant to Rule 12b-1 under the 1940 Act, each Plan (together
with the Distribution Agreement) was approved by the board of trustees,
including a majority of the trustees who are not interested persons of the
Trust (as defined in the 1940 Act) and who have no direct or indirect
financial interest in the operations of the Plan or the Distribution Agreement
(the "Independent Trustees").
 
  Each Plan may be terminated by vote of a majority of the Independent
Trustees, or by vote of a majority of the outstanding voting securities of the
relevant class of shares of the Fund to which the Plan relates. Each Plan may
be amended by vote of the trustees, including a majority of the Independent
Trustees, cast in person at a meeting called for the purpose. Any change in
any Plan that would materially increase the fees payable thereunder by the
Retail Class or Admin Class shares of a Fund requires approval of the Retail
Class or Admin Class shareholders of that Fund. The Trust's trustees review
quarterly written reports of such costs and the purposes for which such costs
have been incurred. Each Plan provides that, for so long as that Plan is in
effect, selection and nomination of those trustees who are not interested
persons of the Trust shall be committed to the discretion of such
disinterested persons.
 
  The Distribution Agreement may be terminated at any time with respect to a
Fund on 60 days' written notice without payment of any penalty by the Trust or
by vote of a majority of the outstanding voting securities of that Fund or by
vote of a majority of the Independent Trustees.
 
  The Distribution Agreement and the Plans will continue in effect for
successive one-year periods, provided that each such continuance is
specifically approved (i) by the vote of a majority of the entire board of
trustees and (ii) by the vote of a majority of the Independent Trustees, in
each case cast in person at a meeting called for that purpose.
 
  Custodial Arrangements. State Street Bank and Trust Company ("State Street
Bank"), Boston, Massachusetts 02102, is the Trust's custodian. As such, State
Street Bank holds in safekeeping certificated securities and cash belonging to
the Funds and, in such capacity, is the registered owner of securities held in
book entry form belonging to the Funds. Upon instruction, State Street Bank
receives and delivers cash and securities of the Funds in connection with Fund
transactions and collects all dividends and other distributions made with
respect to Fund portfolio securities. State Street Bank also maintains certain
accounts and records of the Funds and calculates the total net asset value,
total net income and net asset value per share of each Fund on a daily basis.
   
  Independent Accountants. The Fund's independent accountants are
PricewaterhouseCoopers LLP, One Post Office Square, Boston, Massachusetts.
PricewaterhouseCoopers LLP conducts an annual audit of the Trust's financial
statements, assists in the preparation of the Funds' federal and state income
tax returns and consults with the Funds as to matters of accounting and
federal and state income taxation. The information under the caption
"Financial Highlights" included in the Prospectus has been so included, and
the financial statements incorporated by reference herein from the Fund's 1998
Annual Report have been so incorporated, in reliance on the reports of
PricewaterhouseCoopers LLP, independent accountants, given on the authority of
said firm as experts in auditing and accounting.     
 
                     PORTFOLIO TRANSACTIONS AND BROKERAGE
 
  In placing orders for the purchase and sale of portfolio securities for each
Fund, Loomis Sayles always seeks the best price and execution. Transactions in
unlisted securities are carried out through broker-dealers who make the
primary market for such securities unless, in the judgment of Loomis Sayles, a
more favorable price can be obtained by carrying out such transactions through
other brokers or dealers.
 
                                      26
<PAGE>
 
  Loomis Sayles selects only brokers or dealers which it believes are
financially responsible, will provide efficient and effective services in
executing, clearing and settling an order and will charge commission rates
which, when combined with the quality of the foregoing services, will produce
best price and execution for the transaction. This does not necessarily mean
that the lowest available brokerage commission will be paid. However, the
commissions are believed to be competitive with generally prevailing rates.
Loomis Sayles will use its best efforts to obtain information as to the
general level of commission rates being charged by the brokerage community
from time to time and will evaluate the overall reasonableness of brokerage
commissions paid on transactions by reference to such data. In making such
evaluation, all factors affecting liquidity and execution of the order, as
well as the amount of the capital commitment by the broker in connection with
the order, are taken into account. The Funds, other than the International
Equity and Worldwide Funds, will not pay a broker a commission at a higher
rate than otherwise available for the same transaction in recognition of the
value of research services provided by the broker or in recognition of the
value of any other services provided by the broker which do not contribute to
the best price and execution of the transaction.
 
  Receipt of research services from brokers may sometimes be a factor in
selecting a broker which Loomis Sayles believes will provide best price and
execution for a transaction. These research services include not only a wide
variety of reports on such matters as economic and political developments,
industries, companies, securities, portfolio strategy, account performance,
daily prices of securities, stock and bond market conditions and projections,
asset allocation and portfolio structure, but also meetings with management
representatives of issuers and with other analysts and specialists. Although
it is not possible to assign an exact dollar value to these services, they
may, to the extent used, tend to reduce Loomis Sayles' expenses. Such services
may be used by Loomis Sayles in servicing other client accounts and in some
cases may not be used with respect to the Funds. Receipt of services or
products other than research from brokers is not a factor in the selection of
brokers.
 
  International Equity and Worldwide Funds. In placing orders for the purchase
and sale of securities for the International Equity and Worldwide Funds,
Loomis Sayles follows the same policies as for the other Funds, except that
Loomis Sayles may cause the International Equity and Worldwide Funds to pay a
broker-dealer that provides brokerage and research services to Loomis Sayles
an amount of commission for effecting a securities transaction for those Funds
in excess of the amount another broker-dealer would have charged for effecting
that transaction. Loomis Sayles must determine in good faith that such greater
commission is reasonable in relation to the value of the brokerage and
research services provided by the executing broker-dealer viewed in terms of
that particular transaction or Loomis Sayles' overall responsibilities to the
Trust and its other clients. Loomis Sayles's authority to cause the
International Equity and Worldwide Funds to pay such greater commissions is
also subject to such policies as the Trustees of the Trust may adopt from time
to time.
   
  The following three tables set forth, for the 1996 and 1997 fiscal years and
the 1998 fiscal period (January 1, 1998 through September 30, 1998),
respectively, (1) the aggregate dollar amount of brokerage commissions paid on
portfolio transactions during such period, (2) the dollar amount of
transactions on which brokerage commissions were paid during such period that
were directed to brokers providing research services ("directed transactions")
and (3) the dollar amount of commissions paid on directed transactions during
such period. Funds not listed in a table did not pay brokerage commissions
during the relevant period.     
 
                                      27
<PAGE>
 
                      
                   FISCAL YEAR ENDED DECEMBER 31, 1996     
 
<TABLE>   
<CAPTION>
                                               (1)                      (3)
                                            AGGREGATE      (2)      COMMISSIONS
                                            BROKERAGE    DIRECTED   ON DIRECTED
      FUND                                 COMMISSIONS TRANSACTIONS TRANSACTIONS
      ----                                 ----------- ------------ ------------
      <S>                                  <C>         <C>          <C>
      Growth.............................. $   81,708  $ 97,799,290  $   81,708
      Core Value.......................... $   64,033  $ 17,907,024  $   28,782
      Small Cap Value..................... $  248,992  $ 15,896,278  $   45,316
      International Equity................ $1,002,393  $257,530,857  $1,002,393
      Worldwide........................... $    9,631  $          0  $        0
 
                      FISCAL YEAR ENDED DECEMBER 31, 1997
 
<CAPTION>
                                               (1)                      (3)
                                            AGGREGATE      (2)      COMMISSIONS
                                            BROKERAGE    DIRECTED   ON DIRECTED
      FUND                                 COMMISSIONS TRANSACTIONS TRANSACTIONS
      ----                                 ----------- ------------ ------------
      <S>                                  <C>         <C>          <C>
      Growth.............................. $   81,395  $          0  $        0
      Core Value.......................... $   81,471  $          0  $        0
      Small Cap Value..................... $  579,295  $          0  $        0
      International Equity................ $  759,784  $220,336,814  $  759,784
      Worldwide........................... $    9,953  $  4,261,122  $      697
 
                     NINE MONTHS ENDED SEPTEMBER 30, 1998
 
<CAPTION>
                                               (1)                      (3)
                                            AGGREGATE      (2)      COMMISSIONS
                                            BROKERAGE    DIRECTED   ON DIRECTED
      FUND                                 COMMISSIONS TRANSACTIONS TRANSACTIONS
      ----                                 ----------- ------------ ------------
      <S>                                  <C>         <C>          <C>
</TABLE>    
 
                           DESCRIPTION OF THE TRUST
 
  The Trust, registered with the SEC as a diversified open-end management
investment company, is organized as a Massachusetts business trust under the
laws of Massachusetts by an Agreement and Declaration of Trust (the
"Declaration of Trust") dated February 20, 1991.
 
  The Declaration of Trust currently permits the trustees to issue an
unlimited number of full and fractional shares of each series. Each share of
each Fund represents an equal proportionate interest in such Fund with each
other share of that Fund and is entitled to a proportionate interest in the
dividends and distributions from that Fund. The shares of each Fund do not
have any preemptive rights. Upon termination of any Fund, whether pursuant to
liquidation of the Trust or otherwise, shareholders of that Fund are entitled
to share pro rata in the net assets of that Fund available for distribution to
shareholders. The Declaration of Trust also permits the trustees to charge
shareholders directly for custodial, transfer agency and servicing expenses.
 
  The assets received by each Fund for the issue or sale of its shares and all
income, earnings, profits, losses and proceeds therefrom, subject only to the
rights of creditors, are allocated to, and constitute the underlying assets
of, that Fund. The underlying assets are segregated and are charged with the
expenses with respect to that Fund and with a share of the general expenses of
the Trust. Any general expenses of the Trust that are not readily
 
                                      28
<PAGE>
 
identifiable as belonging to a particular Fund are allocated by or under the
direction of the trustees in such manner as the trustees determine to be fair
and equitable. While the expenses of the Trust are allocated to the separate
books of account of each Fund, certain expenses may be legally chargeable
against the assets of all Funds.
 
  The Declaration of Trust also permits the trustees, without shareholder
approval, to subdivide any series of shares or Fund into various classes of
shares with such dividend preferences and other rights as the trustees may
designate. Shares of each Fund (other than the U.S. Government Securities and
Municipal Bond Funds) are currently divided into two classes, designated
Retail Class and Institutional Class. Additionally, the Bond Fund and Small
Cap Value Fund offer a third class of shares designated the Admin Class. The
trustees may also, without shareholder approval, establish one or more
additional separate portfolios for investments in the Trust or merge two or
more existing portfolios. Shareholders' investments in such an additional or
merged portfolio would be evidenced by a separate series of shares (i.e., a
new "Fund").
 
  The Declaration of Trust provides for the perpetual existence of the Trust.
The Trust or any Fund, however, may be terminated at any time by vote of at
least two-thirds of the outstanding shares of each Fund affected. The
Declaration of Trust further provides that the trustees may also terminate the
Trust or any Fund upon written notice to the shareholders. As a matter of
policy, however, the trustees will not terminate the Trust or any Fund without
submitting the matter to a vote of the shareholders of the Trust or the
relevant Fund.
 
VOTING RIGHTS
 
  As summarized in the Prospectus, shareholders are entitled to one vote for
each full share held (with fractional votes for each fractional share held)
and may vote (to the extent provided in the Declaration of Trust) on the
election of trustees and the termination of the Trust and on other matters
submitted to the vote of shareholders.
 
  The Declaration of Trust provides that on any matter submitted to a vote of
all Trust shareholders, all Trust shares entitled to vote shall be voted
together irrespective of series or sub-series unless the rights of a
particular series or sub-series would be adversely affected by the vote, in
which case a separate vote of that series or sub-series shall also be required
to decide the question. Also, a separate vote shall be held whenever required
by the 1940 Act or any rule thereunder. Rule 18f-2 under the 1940 Act provides
in effect that a class shall be deemed to be affected by a matter unless it is
clear that the interests of each class in the matter are substantially
identical or that the matter does not affect any interest of such class. On
matters affecting an individual series, only shareholders of that series are
entitled to vote. Consistent with the current position of the SEC,
shareholders of all series vote together, irrespective of series, on the
election of trustees and the selection of the Trust's independent accountants,
but shareholders of each series vote separately on other matters requiring
shareholder approval, such as certain changes in investment policies of that
series or the approval of the investment advisory agreement relating to that
series.
 
  There will normally be no meetings of shareholders for the purpose of
electing trustees except that, in accordance with the 1940 Act, (i) the Trust
will hold a shareholders' meeting for the election of trustees at such time as
less than a majority of the trustees holding office have been elected by
shareholders, and (ii) if, as a result of a vacancy on the board of trustees,
less than two-thirds of the trustees holding office have been elected by the
shareholders, that vacancy may be filled only by a vote of the shareholders.
In addition, trustees may be removed from office by a written consent signed
by the holders of two-thirds of the outstanding shares and filed with the
Trust's custodian or by a vote of the holders of two-thirds of the outstanding
shares at a meeting duly called for that purpose, which meeting shall be held
upon the written request of the holders of not less than 10% of the
outstanding shares.
 
  Upon written request by the holders of shares having a net asset value
constituting 1% of the outstanding shares stating that such shareholders wish
to communicate with the other shareholders for the purpose of
 
                                      29
<PAGE>
 
obtaining the signatures necessary to demand a meeting to consider removal of
a trustee, the Trust has undertaken to provide a list of shareholders or to
disseminate appropriate materials (at the expense of the requesting
shareholders).
 
  Except as set forth above, the trustees shall continue to hold office and
may appoint successor trustees. Voting rights are not cumulative.
 
  No amendment may be made to the Declaration of Trust without the affirmative
vote of a majority of the outstanding shares of the Trust, except (i) to
change the Trust's name or to cure technical problems in the Declaration of
Trust and (ii) to establish, change or eliminate the par value of any shares
(currently all shares have no par value).
 
SHAREHOLDER AND TRUSTEE LIABILITY
 
  Under Massachusetts law shareholders could, under certain circumstances, be
held personally liable for the obligations of the Fund of which they are
shareholders. However, the Declaration of Trust disclaims shareholder
liability for acts or obligations of each Fund and requires that notice of
such disclaimer be given in each agreement, obligation or instrument entered
into or executed by the Trust or the trustees. The Declaration of Trust
provides for indemnification out of Fund property for all loss and expense of
any shareholder held personally liable for the obligations of the Fund. Thus,
the risk of a shareholder incurring financial loss on account of shareholder
liability is considered remote since it is limited to circumstances in which
the disclaimer is inoperative and the Fund itself would be unable to meet its
obligations.
 
  The Declaration of Trust further provides that the trustees will not be
liable for errors of judgment or mistakes of fact or law. However, nothing in
the Declaration of Trust protects a trustee against any liability to which the
trustee would otherwise be subject by reason of willful misfeasance, bad
faith, gross negligence or reckless disregard of the duties involved in the
conduct of his office. The By-Laws of the Trust provide for indemnification by
the Trust of the trustees and officers of the Trust except with respect to any
matter as to which any such person did not act in good faith in the reasonable
belief that such action was in or not opposed to the best interests of the
Trust. No officer or trustee may be indemnified against any liability to the
Trust or the Trust's shareholders to which such person would otherwise be
subject by reason of willful misfeasance, bad faith, gross negligence or
reckless disregard of the duties involved in the conduct of his or her office.
 
HOW TO BUY SHARES
 
  The procedures for purchasing shares of each Fund are summarized in the
Prospectus under "How to Purchase Shares."
 
NET ASSET VALUE
 
  The net asset value of the shares of each Fund is determined by dividing
that Fund's total net assets (the excess of its assets over its liabilities)
by the total number of shares of the Fund outstanding and rounding to the
nearest cent. Such determination is made as of the close of regular trading on
the New York Stock Exchange on each day on which that Exchange is open for
unrestricted trading, and no less frequently than once daily on each day
during which there is sufficient trading in a Fund's portfolio securities that
the value of that Fund's shares might be materially affected. During the 12
months following the date of this Statement of Additional Information, the New
York Stock Exchange is expected to be closed on the following weekdays: New
Year's Day, Martin Luther King, Jr. Day, Presidents' Day, Good Friday,
Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas Day.
Equity securities listed on an established securities exchange or on the
Nasdaq National Market System are normally valued at their last sale price on
the exchange where primarily traded or, if there is no reported sale during
the day, and in the case of over-the-counter securities not so listed, at the
last bid price. Long-term debt securities are valued by a pricing service,
which determines valuations of normal institutional-size trading units of
long-term debt securities. Such valuations are determined using methods
 
                                      30
<PAGE>
 
based on market transactions for comparable securities and on various
relationships between securities which are generally recognized by
institutional traders. Other securities for which current market quotations
are not readily available (including restricted securities, if any) and all
other assets are taken at fair value as determined in good faith by the board
of trustees, although the actual calculations may be made by persons acting
pursuant to the direction of the board.
 
  Generally, trading in foreign securities markets is substantially completed
each day at various times prior to the close of regular trading on the New
York Stock Exchange. Occasionally, events affecting the value of foreign fixed
income securities and of equity securities of non-U.S. issuers not traded on a
U.S. exchange may occur between the completion of substantial trading of such
securities for the day and the close of regular trading on the New York Stock
Exchange, which events will not be reflected in the computation of the Fund's
net asset value. If events materially affecting the value of any Fund's
portfolio securities occur during such period, then these securities will be
valued at their fair value as determined in good faith by or in accordance
with procedures approved by the trustees.
 
                             SHAREHOLDER SERVICES
 
OPEN ACCOUNTS
   
  A shareholder's investment in any Fund is automatically credited to an open
account maintained for the shareholder by Boston Financial Data Services, Inc.
("BFDS"), the shareholder servicing agent for State Street Bank. Certificates
representing shares are issued only upon written request to BFDS but are not
issued for fractional shares. Following each transaction in the account, a
shareholder will receive an account statement disclosing the current balance
of shares owned and the details of recent transactions in the account. After
the close of each fiscal year BFDS will send each shareholder a statement
providing federal tax information on dividends and distributions paid to the
shareholder during the year. This should be retained as a permanent record.
Shareholders will be charged a fee for duplicate information.     
 
  The open account system permits the purchase of full and fractional shares
and, by making the issuance and delivery of certificates representing shares
unnecessary, eliminates the problems of handling and safekeeping certificates,
and the cost and inconvenience of replacing lost, stolen, mutilated or
destroyed certificates.
 
  The costs of maintaining the open account system are borne by the Trust, and
no direct charges are made to shareholders. Although the Trust has no present
intention of making such direct charges to shareholders, it reserves the right
to do so. Shareholders will receive prior notice before any such charges are
made.
 
SYSTEMATIC WITHDRAWAL PLAN
   
  A Systematic Withdrawal Plan, referred to in the Prospectus under
"Shareholder Services--Systematic Withdrawal Plan," provides for monthly,
quarterly, semiannual or annual withdrawal payments of $50 or more from the
account of an eligible shareholder, as provided therein, provided that the
account has a value of at least $25,000 at the time the plan is established.
    
  Payments will be made either to the shareholder or to any other person
designated by the shareholder. If payments are issued to an individual other
than the registered owner(s), a signature guarantee will be required on the
Plan application. All shares in an account that is subject to a Systematic
Withdrawal Plan must be held in an open account rather than in certificated
form. Income dividends and capital gain distributions will be reinvested at
the net asset value determined as of the close of regular trading on the New
York Stock Exchange on the record date for the dividend or distribution.
 
  Since withdrawal payments represent proceeds from liquidation of shares, the
shareholder should recognize that withdrawals may reduce and possibly exhaust
the value of the account, particularly in the event of a decline in net asset
value. Accordingly, the shareholder should consider whether a Systematic
Withdrawal Plan and the specified amounts to be withdrawn are appropriate in
the circumstances. The Fund makes no recommendations or representations in
this regard. It may be appropriate for the shareholder to consult a tax
adviser before establishing such a plan. See "Redemptions" and "Income
Dividends, Capital Gain Distributions and Tax Status" below for certain
information as to federal income taxes.
 
                                      31
<PAGE>
 
EXCHANGE PRIVILEGE
   
  Shareholders may redeem their shares of any Fund and have the proceeds
applied on the same day to purchase shares of any other Fund or of New England
Cash Management Trust or New England Tax Exempt Money Market Trust. [Exchange
of shares of the High Yield Fund purchased within one year of such exchanges
will be subject to a redemption fee of 2.00% of the amount exchanged. For
purposes of determining whether a redemption fee is payable with respect to
shares of the High Yield Fund purchased by exchange of shares of another fund,
the one-year period shall be deemed to begin on the date of such purchase by
exchange. This option is summarized in the Prospectus under "Shareholder
Services--Free Exchange Privilege."]    
   
  Exchanges may be effected by (1) making a telephone request by calling 800-
626-9390, provided that a special authorization form is on file with BFDS, or
(2) sending a written exchange request to BFDS accompanied by an account
application for the appropriate fund. The Trust reserves the right to modify
this exchange privilege without prior notice. An exchange constitutes a sale
of the shares for federal income tax purposes on which the investor may
realize a capital gain or loss.     
 
IRAS
 
  Under "Shareholder Services--Retirement Plans," the Prospectus refers to
IRAs established under a prototype plan made available by Loomis Sayles. These
plans may be funded with shares of any Fund, although it is expected that
shares of the Municipal Bond Fund would ordinarily not be an appropriate
investment for these plans.
 
  All income dividends and capital gain distributions of plan participants
must be reinvested. Plan documents and further information can be obtained
from Loomis Sayles.
 
  Check with your financial or tax adviser as to the suitability of Fund
shares for your retirement plan.
 
REDEMPTIONS
 
  The procedures for redemption of Fund shares are summarized in the
Prospectus under "How to Redeem Shares."
 
  Except as noted below, signatures on redemption requests must be guaranteed
by commercial banks, trust companies, savings associations, credit unions or
brokerage firms that are members of domestic securities exchanges. Signature
guarantees by notaries public are not acceptable. However, as noted in the
Prospectus, a signature guarantee will not be required if the proceeds of the
redemption do not exceed $50,000 and the proceeds check is made payable to the
registered owner(s) and mailed to the record address.
 
  If a shareholder selects the telephone redemption service in the manner
described in the next paragraph, Fund shares may be redeemed by making a
telephone call directly to BFDS at 800-626-9390. When a telephonic redemption
request is received, the proceeds are wired to the bank account previously
chosen by the shareholder and a nominal wire fee (currently $5.00) is
deducted. Telephonic redemption requests must be received by BFDS prior to the
close of regular trading on the New York Stock Exchange on a day when the
Exchange is open for business. Requests made after that time or on a day when
the New York Stock Exchange is not open for business cannot be accepted by
BFDS and a new request will be necessary.
 
  In order to redeem shares by telephone, a shareholder must either select
this service when completing the Fund application or must do so subsequently
in writing. When selecting the service, a shareholder must designate a bank
account to which the redemption proceeds should be wired. Any change in the
bank account so designated must be made by furnishing to BFDS a written
request with a signature guarantee. Telephone redemptions may only be made if
an investor's bank is a member of the Federal Reserve System or has a
correspondent bank that is a member of the System. If the account is with a
savings bank, it must have only one correspondent bank that is a member of the
System. The Trust, BFDS, Loomis Sayles Distributors, L.P. and State Street
Bank are not responsible for the authenticity of withdrawal instructions
received by telephone.
 
                                      32
<PAGE>
 
   
  The redemption price will be the net asset value per share next determined
after the redemption request and any necessary special documentation are
received by BFDS in proper form, less, in the case of the High Yield Fund, a
redemption fee of 2.00% of the amount redeemed with respect to shares of that
Fund redeemed within one (1) year of purchase, if applicable. Proceeds
resulting from a written redemption request will normally be mailed to the
shareholder within seven days after receipt of a request in good order.
Telephonic redemption proceeds will normally be wired on the first business
day following receipt of a proper redemption request. In those cases where a
shareholder has recently purchased shares by check and the check was received
less than fifteen days prior to the redemption request, the Fund may withhold
redemption proceeds until the check has cleared.     
 
  Each Fund will normally redeem shares for cash; however, each Fund reserves
the right to pay the redemption price wholly or partly in kind if the board of
trustees of the Trust determines it to be advisable in the interest of the
remaining shareholders. If portfolio securities are distributed in lieu of
cash, the shareholder will normally incur brokerage commissions upon
subsequent disposition of any such securities. However, the Trust has elected
to be governed by Rule 18f-1 under the 1940 Act pursuant to which the Trust is
obligated to redeem shares solely in cash for any shareholder during any 90-
day period up to the lesser of $250,000 or 1% of the total net asset value of
the Trust at the beginning of such period.
 
  A redemption constitutes a sale of the shares for federal income tax
purposes on which the investor may realize a long- or short-term capital gain
or loss. See "Income Dividends, Capital Gain Distributions and Tax Status."
 
          INCOME DIVIDENDS, CAPITAL GAIN DISTRIBUTIONS AND TAX STATUS
 
  As described in the Prospectus under "Dividends, Capital Gain Distributions
and Taxes" it is the policy of each Fund to pay its shareholders, as
dividends, substantially all net investment income and to distribute annually
all net realized capital gains, if any, after offsetting any capital loss
carryovers.
 
  Income dividends and capital gain distributions are payable in full and
fractional shares of the particular Fund based upon the net asset value
determined as of the close of regular trading on the New York Stock Exchange
on the record date for each dividend or distribution. Shareholders, however,
may elect to receive their income dividends or capital gain distributions, or
both, in cash. The election may be made at any time by submitting a written
request directly to BFDS. In order for a change to be in effect for any
dividend or distribution, it must be received by BFDS on or before the record
date for such dividend or distribution.
 
  As required by federal law, detailed federal tax information will be
furnished to each shareholder for each calendar year on or before January 31
of the succeeding year.
 
  Each Fund intends to qualify each year as a regulated investment company
under Subchapter M of the Code. In order so to qualify and to qualify for the
favorable tax treatment accorded regulated investment companies and their
shareholders, the Fund must, among other things, (i) derive at least 90% of
its gross income from dividends, interest, payments with respect to certain
securities loans, gains from the sale of securities or foreign currencies, or
other income (including but not limited to gains from options, futures or
forward contracts) derived with respect to its business of investing in such
stock, securities or currencies; (ii)  distribute with respect to each taxable
year at least 90% of the sum of its taxable net investment income, its tax-
exempt income and the excess, if any, of net short-term capital gains over net
long-term capital losses for such year (iii) at the end of each fiscal quarter
maintain at least 50% of the value of its total assets in cash, U.S.
government securities, securities of other regulated investment companies, and
other securities of issuers which represent, with respect to each issuer, no
more than 5% of the value of the Fund's total assets and 10% of the
outstanding voting securities of such issuer; and (iv) at the end of each
fiscal quarter, not more than 25% of its assets invested in the securities
(other than those of the U.S. government or other regulated investment
companies) of any one issuer or of two or more issuers which the Fund controls
and which are engaged in the same, similar or related trades and businesses.
To the extent it qualifies for treatment as a regulated investment company,
the Fund will not be subject to federal income tax on income paid to its
shareholders in the form of dividends or capital gain distributions.
 
                                      33
<PAGE>
 
  An excise tax at the rate of 4% will be imposed on the excess, if any, of
each Fund's "required distribution" over its actual distributions in any
calendar year. Generally, the "required distribution" is 98% of the Fund's
ordinary income for the calendar year plus 98% of its capital gain net income
recognized during the one-year period ending on October 31 (or December 31, if
the Fund so elects) plus undistributed amounts from prior years. Each Fund
intends to make distributions sufficient to avoid imposition of the excise
tax. Distributions declared by a Fund during October, November or December to
shareholders of record on a date in any such month and paid by the Fund during
the following January will be treated for federal tax purposes as paid by the
Fund and received by shareholders on December 31 of the year in which
declared.
   
  Shareholders of each Fund will be subject to federal income taxes on
distributions made by the Fund (other than "exempt-interest dividends" paid by
the Municipal Bond Fund, as described in the Prospectus) whether received in
cash or additional shares of the Fund. Distributions by each Fund of net
income and short-term capital gains, if any, will be taxable to shareholders
as ordinary income. Distributions designated by a Fund as deriving from net
gains on securities held for more than one year will be taxable to
shareholders as long-term capital gain (generally taxed at a rate of 20% for
noncorporate shareholders), without regard to how long a shareholder has held
shares of the Fund.     
   
  Dividends and distributions on a Fund's shares are generally subject to
federal income tax as described herein to the extent they do not exceed the
Fund's realized income and gains, even though such dividends and distributions
may economically represent a return of a particular shareholder's investment.
Such distributions are likely to occur in respect of shares purchased at a
time when a Fund's net asset value reflects gains that are either unrealized,
or realized but not distributed. Such realized gains may be required to be
distributed even when a Fund's net asset value also reflects unrealized
losses.     
 
  The International Equity, Worldwide and Global Bond Funds each may be
eligible to make an election under Section 853 of the Code so that its
shareholders will be able to claim a credit or deduction on their income tax
returns for, and will be required to treat as part of the amounts distributed
to them, their pro rata portion of qualified taxes paid by the relevant Fund
to foreign countries. The ability of shareholders of the Fund to claim a
foreign tax credit is subject to certain limitations imposed by Section 904 of
the Code, which in general limit the amount of foreign tax that may be used to
reduce a shareholder's U.S. tax liability to that amount of U.S. tax which
would be imposed on the amount and type of income in respect of which the
foreign tax was paid. In addition, a shareholder must hold shares of the Fund
(without protection from risk of loss) on the ex-dividend date and for at
least 16 days during the 30-day period beginning on the date that is 15 days
before the ex-dividend date in order to be eligible to claim a foreign credit
for his or her share of these foreign taxes. A shareholder who for U.S. income
tax purposes claims a foreign tax credit in respect of Fund distributions may
not claim a deduction for foreign taxes paid by the Fund, regardless of
whether the shareholder itemizes deductions. Also, under Section 63 of the
Code, no deduction for foreign taxes may be claimed by shareholders who do not
itemize deductions on their federal income tax returns. It should also be
noted that a tax-exempt shareholder, like other shareholders, will be required
to treat as part of the amounts distributed to it a pro rata portion of the
income taxes paid by the Fund to foreign countries. However, that income will
generally be exempt from United States taxation by virtue of such
shareholder's tax-exempt status and such a shareholder will not be entitled to
either a tax credit or a deduction with respect to such income. The
International Equity, Worldwide and Global Bond Funds will notify shareholders
each year of the amount of dividends and distributions and the shareholder's
pro rata share of qualified taxes paid by each such Fund to foreign countries.
 
  Each Fund's transactions, if any, in foreign currencies are likely to result
in a difference between the Fund's book income and taxable income. This
difference may cause a portion of the Fund's income distributions to
constitute a return of capital for tax purposes or require the Fund to make
distributions exceeding book income to avoid excise tax liability and to
qualify as a regulated investment company.
 
  Investment by a Fund in "passive foreign investment companies" could subject
the Fund to U.S. federal income tax or other charge on the proceeds from the
sale of its investment in such a company; however, this tax can be avoided by
making an election to mark such investments to market annually or to treat the
passive foreign investment company as a "qualified electing fund."
 
                                      34
<PAGE>
 
  If a Fund engages in hedging transactions, including hedging transactions in
options, futures contracts, and straddles, or other similar transactions, it
will be subject to special tax rules (including constructive sale, mark-to-
market, straddle, wash sale, and short sale rules), the effect of which may be
to accelerate income to the Fund, defer losses to the Fund, cause adjustments
in the holding periods of the Fund's securities, or convert short-term capital
losses into long-term capital losses. These rules could therefore affect the
amount, timing and character of distributions to shareholders. Each Fund will
endeavor to make any available elections pertaining to such transactions in a
manner believed to be in the best interests of the Fund.
 
  A Fund's investment in securities issued at a discount and certain other
obligations will (and investments in securities purchased at a discount may)
require the Fund to accrue and distribute income not yet received. In such
cases, a Fund may be required to sell assets (including when it is not
advantageous to do so) to generate the cash necessary to distribute as
dividends to its shareholders all of its income and gains and therefore to
eliminate any tax liability at the Fund level.
   
  Generally a Fund may designate dividends eligible for the dividends-received
deduction only to the extent that such dividends are derived from dividends
paid to the Fund with respect to which Fund could have taken the dividends-
received deduction if it had been a regular corporation. The dividends-
received deduction is not available to non-corporate shareholders, Subchapter
S corporations or corporations who do not hold their shares for at least 46
days during the 90-day period beginning on the date that is 45 days before the
ex-dividend date.     
   
  Redemptions and exchanges of each Fund's shares are taxable events and,
accordingly, shareholders may realize gains and losses on these transactions.
In general, any gain realized upon a taxable disposition of shares will be
treated as long-term capital gain if the shares have been held for more than
one year. Otherwise the gain on the sale, exchange or redemption of Fund
shares will be treated as short-term capital gain. However, if a shareholder
sells Fund shares at a loss within six months after purchasing the shares, the
loss will be treated as a long-term capital loss to the extent of any long-
term capital gain distributions received by the shareholder. Furthermore, no
loss will be allowed on the sale of Fund shares to the extent the shareholder
acquired other shares of the same Fund within 30 days prior to the sale of the
loss shares or 30 days after such sale.     
   
  [At December 31, 1997, the Short-Term Bond Fund had a net tax basis capital
loss carryforward of approximately $418,097 which may be applied against any
realized net taxable gains of each succeeding year until fully utilized or
expiration of $129,507 of such loss carryforward on December 31, 2002, and
$288,590 of such loss carryforward on December 31, 2003, whichever occurs
first.]     
   
  [At December 31, 1997, the U.S. Government Securities Fund had a net tax
basis capital loss carryforward of approximately $915,332 which may be applied
against any realized net taxable gains of each succeeding year until fully
utilized or expiration of $177,989 of such loss carryforward on December 31,
2002, and $737,343 of such loss carryforward on December 31, 2003, whichever
occurs first.]     
 
  The foregoing is a general and abbreviated summary of the applicable
provisions of the Code and regulations currently in effect. For the complete
provisions, reference should be made to the pertinent Code sections and
regulations. The Code and regulations are subject to change by legislative or
administrative action.
 
  Dividends and distributions also may be subject to foreign, state and local
taxes. Shareholders are urged to consult their tax advisers regarding specific
questions as to federal, state, foreign, or local taxes.
   
  The foregoing discussion relates solely to U.S. federal income tax law. Non-
U.S. investors should consult their tax advisers concerning the tax
consequences of ownership of shares of the Fund, including the possibility
that distributions may be subject to a 30% United States withholding tax (or a
reduced rate of withholding provided by treaty). The Internal Revenue Service
recently revised its regulations affecting the application to foreign
investors of the back-up withholding tax rules. The new regulations will
generally be effective for payments made on or after January 1, 1999 (although
transition rules will apply). In some circumstances, the new rules will
increase the certification and filing requirements imposed on foreign
investors in order to qualify     
 
                                      35
<PAGE>
 
   
  The foregoing discussion relates solely to U.S. federal income tax law. Non-
U.S. investors should consult their tax advisers concerning the tax
consequences of ownership of shares of the Fund, including the possibility
that distributions may be subject to a 30% United States withholding tax (or a
reduced rate of withholding provided by treaty). The Internal Revenue Service
recently revised its regulations affecting the application to foreign
investors of the back-up withholding tax rules. The new regulations will
generally be effective for payments made on or after January 1, 1999 (although
transition rules will apply). In some circumstances, the new rules will
increase the certification and filing requirements imposed on foreign
investors in order to qualify for exemption from the 31% back-up withholding
tax and for reduced withholding tax rates under income tax treaties. Foreign
investors in each Fund should consult their advisors with respect to the
potential application of these new regulations.     
       
                             FINANCIAL STATEMENTS
   
  The financial statements of each Fund included in the Trust's 1998 Annual
Report, filed with the Securities and Exchange Commission on November 24,
1998, are incorporated by reference to such Report.     
 
                     CALCULATION OF YIELD AND TOTAL RETURN
 
  Yield. Yield with respect to a Fund will be computed by dividing such Fund's
net investment income for a recent 30-day period by the maximum offering price
(reduced by any undeclared earned income expected to be paid shortly as a
dividend) on the last trading day of that period. Net investment income will
reflect amortization of any market value premium or discount of fixed income
securities (except for obligations backed by mortgages or other assets) and
may include recognition of a pro rata portion of the stated dividend rate of
dividend paying portfolio securities. The Funds' yields will vary from time to
time depending upon market conditions, the composition of the Funds'
portfolios and operating expenses of the Trust allocated to each Fund. These
factors, and possible differences in the methods used in calculating yield,
should be considered when comparing a Fund's yield to yields published for
other investment companies and other investment vehicles. Yield should also be
considered relative to changes in the value of the Funds' shares and to the
relative risks associated with the investment objectives and policies of the
Funds.
 
  At any time in the future, yields may be higher or lower than past yields
and there can be no assurance that any historical results will continue.
 
  Investors in the Funds are specifically advised that the net asset value per
share of each Fund may vary, just as yields for each Fund may vary. An
investor's focus on yield to the exclusion of the consideration of the value
of shares of that Fund may result in the investor's misunderstanding the total
return he or she may derive from that Fund.
 
  Total Return. Total Return with respect to a Fund is a measure of the change
in value of an investment in such Fund over the period covered, and assumes
any dividends or capital gains distributions are reinvested immediately,
rather than paid to the investor in cash. The formula for total return used
herein includes four steps: (1) adding to the total number of shares purchased
through a hypothetical $1,000 investment in the Fund all additional shares
which would have been purchased if all dividends and distributions paid or
distributed during the period had been immediately reinvested; (2) calculating
the value of the hypothetical initial investment of $1,000 as of the end of
the period by multiplying the total number of shares owned at the end of the
period by the net asset value per share on the last trading day of the period;
(3) assuming redemption at the end of the period; and (4) dividing the
resulting account value by the initial $1,000 investment.
 
                                      36
<PAGE>
 
                            PERFORMANCE COMPARISONS
 
  Yield and Total Return. Each Fund may from time to time include its total
return information in advertisements or in information furnished to present or
prospective shareholders. Each of the Bond, Global Bond, U.S. Government
Securities, Municipal Bond, Short-Term Bond, Investment Grade Bond,
Intermediate Maturity Bond, High Yield and Worldwide Funds may from time to
time include the yield and/or total return of its shares in advertisements or
information furnished to present or prospective shareholders. Each Fund may
from time to time include in advertisements or information furnished to
present or prospective shareholders (i) the ranking of performance figures
relative to such figures for groups of mutual funds categorized by Lipper
Analytical Services, Inc. or Micropal, Inc. as having similar investment
objectives, (ii) the rating assigned to the Fund by Morningstar, Inc. based on
the Fund's risk-adjusted performance relative to other mutual funds in its
broad investment class, and/or (iii) the ranking of performance figures
relative to such figures for mutual funds in its general investment category
as determined by CDA/Weisenberger's Management Results.
 
  Volatility. Each Fund may quote various measures of its volatility and
benchmark correlation. In addition, a Fund may compare these measures to those
of other funds and indices. Measures of volatility seek to compare a Fund's
historical share price fluctuations or total returns to those of a benchmark.
Measures of benchmark correlation indicate the extent to which a Fund's
returns change in ways similar to those of the benchmark. All measures of
volatility and correlation are calculated using averages of historical data.
Each Fund may utilize charts and graphs to present a Fund's volatility and
average annual total return. Each Fund may also discuss or illustrate examples
of interest rate sensitivity.
 
  Lipper Analytical Services, Inc. distributes mutual fund rankings monthly.
The rankings are based on total return performance calculated by Lipper,
generally reflecting changes in net asset value adjusted for reinvestment of
capital gains and income dividends. They do not reflect deduction of any sales
charges. Lipper rankings cover a variety of performance periods, including
year-to-date, 1-year, 5-year, and 10-year performance. Lipper classifies
mutual funds by investment objective and asset category.
 
  Micropal, Inc. distributes mutual fund rankings weekly and monthly. The
rankings are based upon performance calculated by Micropal, generally
reflecting changes in net asset value that can be adjusted for the
reinvestment of capital gains and dividends. If deemed appropriate by the
user, performance can also reflect deductions for sales charges. Micropal
rankings cover a variety of performance periods, including year-to-date, 1-
year, 5-year and 10-year performance. Micropal classifies mutual funds by
investment objective and asset category.
   
  Morningstar, Inc. distributes mutual fund ratings monthly. The ratings are
divided into five groups: highest, above average, neutral, below average and
lowest. They represent a fund's historical risk/reward ratio relative to other
funds in its broad investment class as determined by Morningstar, Inc.
Morningstar ratings cover a variety of performance periods, including 3-year,
5-year, 10-year and overall performance. The performance factor for the
overall rating is a weighted-average return performance (if available)
reflecting deduction of expenses and sales charges. Performance is adjusted
using quantitative techniques to reflect the risk profile of the fund. The
ratings are derived from a purely quantitative system that does not utilize
the subjective criteria customarily employed by rating agencies such as
Standard & Poor's and Moody's Investor Service, Inc.     
 
  CDA/Weisenberger's Management Results publishes mutual fund rankings and is
distributed monthly. The rankings are based entirely on total return
calculated by Weisenberger for periods such as year-to-date, 1-year, 3-year,
5-year and 10-year Mutual funds are ranked in general categories (e.g.,
international bond, international equity, municipal bond, and maximum capital
gain). Weisenberger rankings do not reflect deduction of sales charges or
fees.
 
  Performance information may also be used to compare the performance of the
Fund to certain widely acknowledged standards or indices for stock and bond
market performance, such as those listed below.
 
  Consumer Price Index. The Consumer Price Index, published by the U.S. Bureau
of Labor Statistics, is a statistical measure of changes, over time, in the
prices of goods and services in major expenditure groups.
 
                                      37
<PAGE>
 
  Dow Jones Industrial Average. The Dow Jones Industrial Average is a market
value-weighted and unmanaged index of 30 large industrial stocks traded on the
New York Stock Exchange.
 
  Lehman Brothers Government/Corporate Bond Index. The Lehman Brothers
Government/Corporate Bond Index is an index of publicly issued U.S. Treasury
obligations, debt obligations of U.S. government agencies (excluding mortgage-
backed securities), fixed-rate, non-convertible, investment-grade corporate
debt securities and U.S. dollar-denominated, SEC-registered non-convertible
debt issued by foreign governmental entities or international agencies used as
a general measure of the performance of fixed-income securities.
 
  Lehman Brothers 1-3 Year Government Index. The Index contains fixed rate
debt issues of the U.S. government or its agencies rated investment grade or
higher with at least one year maturity and an outstanding par value of at
least $100 million for U.S. government issues.
 
  Lehman Brothers Government Bond Index. The Lehman Brothers Government Bond
Index is composed of all publicly issued, nonconvertible, domestic debt of the
U.S. government or any of its agencies, quasi-federal corporations, or
corporate debt guaranteed by the U.S. government.
 
  Lehman Brothers Municipal Bond Index. The Lehman Brothers Municipal Bond
Index is computed from the prices of approximately 21,000 bonds consisting of
roughly 30% revenue bonds, 30% government obligation bonds, 27% insured bonds
and 13% prerefunded bonds.
 
  MSCI-EAFE Index. The MSCI-EAFE Index contains over 1000 stocks from 20
different countries with Japan (approximately 50%), United Kingdom, France and
Germany being the most heavily weighted.
 
  MSCI-EAFE ex-Japan Index. The MSCI-EAFE ex-Japan Index consists of all
stocks contained in the MSCI-EAFE Index, other than stocks from Japan.
 
  Merrill Lynch Government/Corporate Index. The Merrill Lynch
Government/Corporate Index is a composite of approximately 4,900 U.S.
government and corporate debt issues with at least $25 million outstanding,
greater than one year maturity, and credit ratings of investment grade or
higher.
 
  Merrill Lynch High Yield Index. The Merrill Lynch High Yield Index includes
over 750 issues and represents public debt greater than $10 million (original
issuance rated BBB/BB and below).
 
  Russell 2000 Index. The Russell 2000 Index is comprised of the 2000 smallest
of the 3000 largest U.S.-domiciled corporations, ranked by market
capitalization.
 
  Salomon Brothers World Government Bond Index. The Salomon Brothers World
Government Bond Index includes a broad range of institutionally-traded fixed-
rate government securities issued by the national governments of the nine
countries whose securities are most actively traded. The index generally
excludes floating- or variable-rate bonds, securities aimed principally at
non-institutional investors (such as U.S. Savings Bonds) and private-placement
type securities.
 
  Standard & Poor's/Barra Growth Index. The Standard & Poor's/Barra Growth
Index is constructed by ranking the securities in the S&P 500 by price-to-book
ratio and including the securities with the highest price-to-book ratios that
represent approximately half of the market capitalization of the S&P 500.
 
  Standard & Poor's/Barra Value Index. The Standard & Poor's/Barra Value Index
is constructed by ranking the securities in the S&P 500 by price-to-book ratio
and including the securities with the lowest price-to-book ratios that
represent approximately half of the market capitalization of the S&P 500.
 
  Standard & Poor's 500 Composite Stock Price Index (the "S&P 500"). The S&P
500 is a market value-weighted and unmanaged index showing the changes in the
aggregate market value of 500 stocks relative to the base period 1941-43. The
S&P 500 is composed almost entirely of common stocks of companies listed on
the
 
                                      38
<PAGE>
 
New York Stock Exchange, although the common stocks of a few companies listed
on the American Stock Exchange or traded over-the-counter are included. The
500 companies represented include 400 industrial, 60 transportation and 40
financial services concerns. The S&P 500 represents about 80% of the market
value of all issues traded on the New York Stock Exchange. The S&P 500 is the
most common index for the overall U.S. stock market.
 
  From time to time, articles about the Funds regarding performance, rankings
and other characteristics of the Funds may appear in publications including,
but not limited to, the publications included in Appendix A. In particular,
some or all of these publications may publish their own rankings or
performance reviews of mutual funds, including the Funds. References to or
reprints of such articles may be used in the Funds' promotional literature.
References to articles regarding personnel of Loomis Sayles who have portfolio
management responsibility may also be used in the Funds' promotional
literature. For additional information about the Funds' advertising and
promotional literature, see Appendix B.
 
                                      39
<PAGE>
 
                              INSTITUTIONAL CLASS
 
                               PERFORMANCE DATA*
   
  The manner in which total return and yield of the Funds will be calculated
for public use is described above. The table summarizes the calculation of
total return and yield for Institutional Class shares of the Funds, where
applicable, (i) for the one-year period ended September 30, 1998, (ii) for the
three-year period ended September 30, 1998, (iii) the five-year period ended
September 30, 1998, and (iv) since the modified inception and (v) since actual
inception (May, 1991 for all Funds other than the High Yield, Intermediate
Maturity Bond, Investment Grade Bond, Mid-Cap Growth, Mid-Cap Value, Short-
Term Bond, Small Cap Growth, Strategic Value, and Worldwide Funds, December
31, 1996 for the Intermediate Maturity Bond, Investment Grade Bond, Mid-Cap
Growth, Mid-Cap Value, Small Cap Growth and Strategic Value Funds, August,
1992 for the Short-Term Bond Fund, May, 1996 for the Worldwide Fund and
September, 1996 for the High Yield Fund) through December 31, 1997.     
 
<TABLE>   
<CAPTION>
                                           AVERAGE ANNUAL TOTAL RETURN
                         ----------------------------------------------------------------
                                             FOR THE
                                    FOR THE  THREE-                  FROM        FROM
                          CURRENT   ONE-YEAR  YEAR      FOR THE    MODIFIED     ACTUAL
                            SEC      PERIOD  PERIOD    FIVE-YEAR   INCEPTION INCEPTION***
                           YIELD     ENDED    ENDED     PERIOD      THROUGH    THROUGH
                         AT 9/30/98 9/30/98  9/30/98 ENDED 9/30/98 9/30/98**   9/30/98
                         ---------- -------- ------- ------------- --------- ------------
<S>                      <C>        <C>      <C>     <C>           <C>       <C>
FUND
Growth..................      NA     (9.92)%  11.36%     11.28%     12.04 %    12.94 %
Core Value..............      NA     (5.39)%  15.92%     15.89%     13.90 %    14.63 %
Small Cap Value.........      NA    (18.32)%  12.51%     11.13%     16.17 %    16.39 %
International Equity....      NA    (14.60)%   3.14%      5.96%      6.88 %     6.75 %
Worldwide...............      NA    (17.84)%     NA         NA      (0.04)%     0.33 %
Mid-Cap Growth..........      NA    (10.75)%     NA         NA       6.80 %     6.80 %
Mid-Cap Value...........      NA    (13.03)%     NA         NA       5.90 %     5.90 %
Small Cap Growth........      NA    (17.37)%     NA         NA       2.10 %     2.10 %
Strategic Value.........      NA    (18.40)%     NA         NA       3.71 %     3.71 %
Bond....................    8.47%    (0.41)%   9.44%      9.98%     12.55 %    12.41 %
Global Bond.............    6.37%    (2.29)%   8.55%      6.57%      8.45 %     8.38 %
U.S. Government Securi-
 ties...................    5.09%    14.43 %   9.64%      7.41%     10.56 %    10.55 %
Municipal Bond..........    4.23%     9.25 %   7.99%      5.92%      7.87 %     7.90 %
Short-Term Bond.........    4.82%     8.63 %   7.06%      6.32%      6.28 %     6.28 %
High Yield..............   14.00%   (17.96)%     NA         NA      (2.18)%    (1.51)%
Intermediate Maturity
 Bond...................    6.73%     3.67 %     NA         NA       5.69 %     5.69 %
Investment Grade Bond...    7.64%     1.54 %     NA         NA       8.08 %     8.08 %
</TABLE>    
- --------
   
  * Performance (for other than the one-year, three-year and five-year periods
    for the Core Value and Small Cap Value Funds, and the three-year and five-
    year periods for the Bond Fund) would have been lower if a portion of the
    management fee had not been waived by Loomis Sayles. In the absence of
    this limitation, actual yield and total return would have been as follows:
    Growth, (10.09)%, 11.29%, 11.24%, 12.01% and 12.91% for the one-year
    period, the three-year period, the five-year period, the period since
    modified inception and the period since actual inception, respectively;
    Core Value, 13.81% and 14.55% for the period since modified inception and
    the period since actual inception, respectively; Small Cap Value, 16.12%
    and 16.35% for the period since modified inception and the period since
    actual inception, respectively; International Equity, (14.78)%, 3.04%,
    5.91%, 6.53% and 6.46% for the one-year period, the three-year period, the
    five-year period, the period since modified inception and the period since
    actual inception, respectively; Worldwide, (19.96)%, (2.18)% and (1.82)%
    for the one-year period, the period since modified inception and the
    period since actual inception, respectively; Mid-Cap Growth, (17.44)%,
    (0.43)% and (0.43)% for the one-year period, the period since modified
    inception and the period since actual inception, respectively; Mid-Cap
    Value, (16.94)%, 1.36% and 1.36% for the one-year period, the     
 
                                      40
<PAGE>
 
       
    period since modified inception and the period since actual inception,
    respectively; Small Cap Growth, (19.43)%, (1.13)% and (1.13)% for the one-
    year period, the period since modified inception and the period since
    actual inception, respectively; Strategic Value, (29.65)%, (9.70)% and
    (9.70)% for the one-year period, the period since modified inception and
    the period since actual inception, respectively; Bond, 8.39% (yield) and
    (8.42)%, 12.47% and 12.34% for the one-year period, the period since
    modified inception, and the period since actual inception, respectively;
    Global Bond, 5.70% (yield), and (2.58)%, 8.31%, 6.42%, 8.08% and 8.15% for
    the one-year period, the three-year period, the five-year period, the
    period since modified inception and the period since actual inception,
    respectively; U.S. Government Securities, 4.69% (yield), and 13.99%,
    9.32%, 7.17%, 10.28% and 10.28% for the one-year period, the three-year
    period, the five-year period, the period since modified inception and the
    period since actual inception, respectively; Municipal Bond, 2.90%
    (yield), and 8.12%, 6.96%, 4.91%, 5.45% and 3.49% for the one-year period,
    the three-year period, the five-year period, the period since modified
    inception and the period since actual inception, respectively; Short-Term
    Bond, 4.31% (yield), and 8.03%, 6.75%, 6.12%, 5.93% and 5.88% for the one-
    year period, the three-year period, the five-year period, the period since
    modified inception and the period since actual inception , respectively;
    High Yield, 11.15% (yield), (19.98)%, (5.92)% and (5.43)% for the one-year
    period, the period since modified inception and the period since actual
    inception, respectively; Intermediate Maturity Bond, 4.60% (yield), and
    1.60%, 3.25% and 3.25% for the one-year period, the period since modified
    inception and the period since actual inception, respectively; and
    Investment Grade Bond, 3.09% (yield), and (2.95)%, 2.71% and 2.71% for the
    one-year period, the period since modified inception and the period since
    actual inception, respectively.     
 ** For the Mid-Cap Growth Fund, Mid-Cap Value Fund, Small Cap Growth Fund,
    Strategic Value Fund, Intermediate Maturity Bond Fund, and Investment
    Grade Bond Fund, the modified inception date is December 31, 1996. For the
    Short-Term Bond Fund the modified inception date is August 31, 1992, for
    the Worldwide Fund--May 31, 1996, for the High Yield Fund--September 30,
    1996 and for all other Funds--May 31, 1991.
*** Actual Inception Dates:
 
<TABLE>
      <S>                                                     <C>
      Growth................................................. May 16, 1991
      Core Value............................................. May 13, 1991
      Small Cap Value........................................ May 13, 1991
      International Equity................................... May 10, 1991
      Worldwide.............................................. May 1, 1996
      Mid-Cap Growth......................................... December 31, 1996
      Mid-Cap Value.......................................... December 31, 1996
      Small Cap Growth....................................... December 31, 1996
      Strategic Value........................................ December 31, 1996
      Bond................................................... May 16, 1991
      Global Bond............................................ May 10, 1991
      U.S. Government Securities............................. May 21, 1991
      Municipal Bond......................................... May 29, 1991
      Short-Term Bond........................................ August 3, 1992
      High Yield............................................. September 11, 1996
      Intermediate Maturity Bond............................. December  31, 1996
      Investment Grade Bond.................................. December  31, 1996
</TABLE>
 
                                      41
<PAGE>
 
                                 RETAIL CLASS
 
                               PERFORMANCE DATA*
   
  The manner in which total return and yield of the Funds will be calculated
for public use is described above. The table summarizes the calculation of
total return and yield for Retail Class shares of the Funds, where applicable,
(i) for the one-year period ended September 30, 1998, (ii) since the modified
inception December 31, 1996 through September 30, 1998 and (iii) since the
actual inception December 31, 1996 through September 30, 1998.     
 
<TABLE>   
<CAPTION>
                                                           AVERAGE ANNUAL TOTAL
                                                                  RETURN
                                                           ---------------------
                                                           FOR THE
                                                 CURRENT   ONE-YEAR FROM ACTUAL
                                                   SEC      PERIOD  INCEPTION **
                                                  YIELD     ENDED     THROUGH
                                                AT 9/30/98 9/30/98    9/30/98
                                                ---------- -------- ------------
<S>                                             <C>        <C>      <C>
FUND
Growth.........................................      NA    (10.15)%    7.97 %
Core Value.....................................      NA     (5.69)%   12.47 %
Small Cap Value................................      NA    (18.57)%    2.85 %
International Equity...........................      NA    (14.81)%   (3.68)%
Worldwide......................................      NA    (18.15)%   (4.78)%
Mid-Cap Growth.................................      NA    (11.07)%    6.54 %
Mid-Cap Value..................................      NA    (13.29)%    5.63 %
Small Cap Growth...............................      NA    (17.59)%    1.90 %
Strategic Value................................      NA    (18.63)%    3.45 %
Bond...........................................    8.22%    (0.67)%    6.25 %
Global Bond....................................    6.13%    (2.63)%    1.55 %
Short-Term Bond................................    4.56%     8.35 %    7.73 %
High Yield.....................................   13.75%   (18.18)%   (3.70)%
Intermediate Maturity Bond.....................    6.48%     3.52 %    5.51 %
Investment Grade Bond..........................    7.39%     1.29%     7.83 %
</TABLE>    
   
  * Performance would have been lower if a portion of the management fee had
    not been waived by Loomis Sayles. In the absence of this limitation,
    actual yield and total return would have been as follows: Growth,
    (15.85)%, (0.14)% and (0.14)% for the one-year period, the period since
    modified inception and the period since actual inception, respectively;
    Core Value, (7.72)%, 9.39% and 9.39% for the one-year period, the period
    since modified inception and the period since actual inception,
    respectively; Small Cap Value, (19.60)%, 2.80% and 2.80% for the one-year
    period, the period since modified inception and the period since actual
    inception, respectively; International Equity, (25.32)%, (17.19)% and
    (17.19)% for the one-year period, the period since modified inception and
    the period since actual inception, respectively; Worldwide, (89.15)%,
    (141.76)% and (141.76)% for the one-year period, the period since modified
    inception and the period since actual inception, respectively; Mid-Cap
    Growth, (39.94)%, (27.99)% and (27.99)% for the one-year period, the
    period since modified inception and the period since actual inception,
    respectively; Mid-Cap Value, (29.02)%, (15.66)% and (15.66)% for the one-
    year period, the period since modified inception and the period since
    actual inception, respectively; Small Cap Growth, (21.15)%, (2.99)% and
    (2.99)% for the one-year period, the period since modified inception and
    the period since actual inception, respectively; Strategic Value,
    (34.31)%, (14.94)% and (14.94)% for the one-year period, the period since
    modified inception and the period since actual inception, respectively;
    Bond 8.10% (yield), (0.77)%, 6.11% and 6.11% for the one-year period, the
    period since modified inception and the period since actual inception,
    respectively; Global Bond, 5.19% (yield), (3.43)%, 0.55% and 0.55% for the
    one-year period, the period since modified inception and the period since
    actual inception, respectively; Short-Term Bond, 1.85%, 0.16%, (4.10)% and
    (4.10)% for the one-year period, the period since modified inception and
    the period since actual inception, respectively; High Yield, 10.75%
    (yield), (20.38)%, (6.70)% and (6.70)% for the one-year period, the period
    since modified inception and the period since actual inception,
    respectively; Intermediate Maturity Bond, 1.86% (yield), (3.55)%, (4.40)%
    and (4.40)% for the one-year period, the period since modified inception
    and the period since actual inception, respectively; and Investment Grade
    Bond, 2.41% (yield), (4.59)%, 0.34% and 0.34% for the one-year period, the
    period since modified inception and the period since actual inception,
    respectively.     
 ** The modified inception date and actual inception date for each of the
    Retail Class of each of the Funds is December 31, 1996.
 
                                      42
<PAGE>
 
                                  
                               ADMIN CLASS     
                               
                            PERFORMANCE DATA*     
 
<TABLE>   
<CAPTION>
                                        AVERAGE
                                      ANNUAL TOTAL
                                         RETURN    AVERAGE ANNUAL TOTAL RETURN
                                      ------------ ----------------------------
                                                              FROM      FROM
                            CURRENT   FROM ACTUAL  FOR THE  MODIFIED   ACTUAL
                              SEC     INCEPTION ** ONE-YEAR INCEPTION INCEPTION
                             YIELD      THROUGH     PERIOD   THROUGH   THROUGH
                           AT 9/30/98   9/30/98     ENDED    7/30/98   9/30/98
                           ---------- ------------ -------- --------- ---------
     <S>                   <C>        <C>          <C>      <C>       <C>
     FUND
     Small Cap Value......              (16.54)%     N/A     (2.47)%   (1.33)%
     Bond.................   7.98%       (1.33)%     N/A    (14.62)%  (16.54)%
</TABLE>    
- --------
   
 *  Performance would have been lower if a portion of the management fee had
    not been waived by Loomis Sayles. In the absence of this limitation,
    actual yield and total return for the Bond Fund would have been   %
    (yield),   %,   %, and   % for the one-year period, the period since
    modified inception and the period since actual inception, respectively;
    and for the Small Cap Value Fund   % and   % for the period since modified
    inception and the period since actual inception.     
   
 **  Actual Inception Date for the Bond Fund is       and for the Small Cap
     Value Fund is      .     
 
                                      43
<PAGE>
 
                                   APPENDIX A
 
                 PUBLICATIONS THAT MAY CONTAIN FUND INFORMATION
 
ABC and affiliates                        Financial Services Week
Adam Smith's Money World                  Financial World
America On Line                           Fitch Insights
Anchorage Daily News                      Forbes
Atlanta Constitution                      Fort Worth Star-Telegram
Atlanta Journal                           Fortune
Arizona Republic                          Fox Network and affiliates
Austin American Statesman                 Fund Action
Baltimore Sun                             Fund Decoder
Bank Investment Marketing                 Global Finance
Barron's                                  (the) Guarantor
Bergen County Record (NJ)                 Hartford Courant
Bloomberg Business News                   Houston Chronicle
Bond Buyer                                INC
Boston Business Journal                   Indianapolis Star
Boston Globe                              Individual Investor
Boston Herald                             Institutional Investor
Broker World                              International Herald Tribune
Business Radio Network                    Internet
Business Week                             Investment Advisor
CBS and affiliates                        Investment Company Institute
CDA Investment Technologies               Investment Dealers Digest
CFO                                       Investment Profiles
Changing Times                            Investment Vision
Chicago Sun Times                         Investor's Daily
Chicago Tribune                           IRA Reporter
Christian Science Monitor                 Journal of Commerce
Christian Science Monitor News Service    Kansas City Star
Cincinnati Enquirer                       KCMO (Kansas City)
Cincinnati Post                           KOA-AM (Denver)
CNBC                                      LA Times
CNN                                       Leckey, Andrew (syndicated column)
Columbus Dispatch                         Life Association News
CompuServe                                Lifetime Channel
Dallas Morning News                       Miami Herald
Dallas Times-Herald                       Milwaukee Sentinel
Denver Post                               Money Magazine
Des Moines Register                       Money Maker
Detroit Free Press                        Money Management Letter
Donoghues Money Fund Report               Morningstar
Dorfman, Dan (syndicated column)          Mutual Fund Market News
Dow Jones News Service                    Mutual Funds Magazine
Economist                                 National Public Radio
FACS of the Week                          National Underwriter
Fee Adviser                               NBC and affiliates
Financial News Network                    New England Business
Financial Planning                        New England Cable News
Financial Planning on Wall Street         New Orleans Times-Picayune
Financial Research Corp.                  New York Daily News
 
                                       44
<PAGE>
 
New York Times                            Smart Money
Newark Star Ledger                        St. Louis Post Dispatch
Newsday                                   St. Petersburg Times
Newsweek                                  Standard & Poor's Outlook
Nightly Business Report                   Standard & Poor's Stock Guide
Orange County Register                    Stanger's Investment Advisor
Orlando Sentinel                          Stockbroker's Register
Palm Beach Post                           Strategic Insight
Pension World                             Tampa Tribune
Pensions and Investments                  Time
Personal Investor                         Tobias, Andrew (syndicated column)
Philadelphia Inquirer                     Toledo Blade
Porter, Sylvia (syndicated column)        UP
Portland Oregonian                        US News and World Report
Prodigy                                   USA Today
Public Broadcasting Service               USA TV Network
Quinn, Jane Bryant (syndicated column)    Value Line
Registered Representative                 Wall Street Journal
Research Magazine                         Wall Street Letter
Resource                                  Wall Street Week
Reuters                                   Washington Post
Rocky Mountain News                       WBZ
Rukeyser's Business (syndicated column)   WBZ-TV
Sacramento Bee                            WCVB-TV
San Diego Tribune                         WEEI
San Francisco Chronicle                   WHDH
San Francisco Examiner                    Worcester Telegram
San Jose Mercury                          World Wide Web
Seattle Post-Intelligencer                Worth Magazine
Seattle Times                             WRKO
Securities Industry Management
 
                                       45
<PAGE>
 
                                                                     APPENDIX B
 
                    ADVERTISING AND PROMOTIONAL LITERATURE
 
  Loomis Sayles Funds' advertising and promotional material may include, but
is not limited to, discussions of the following information:
 
    Loomis Sayles Funds' participation in wrap fee and no transaction fee
  programs
 
    Loomis Sayles Funds and Loomis, Sayles & Company, L.P. Website
 
    Characteristics of Loomis Sayles including the number and locations of
  its offices, its investment practices and clients and assets under
  management
 
    Specific and general investment philosophies, strategies, processes and
  techniques
 
    Specific and general sources of information, economic models, forecasts
  and data services utilized, consulted or considered in the course of
  providing advisory or other services
 
    Industry conferences at which Loomis Sayles participates
 
    Current capitalization, levels of profitability and other financial
  information
 
    Identification of portfolio managers, researchers, economists, principals
  and other staff members and employees and descriptions of Loomis Sayles'
  resources devoted to such staff
 
    The specific credentials of the above individuals, including but not
  limited to, previous employment, current and past positions, titles and
  duties performed, industry experience, educational background and degrees,
  awards and honors
 
    Specific identification of, and general reference to, current individual,
  corporate and institutional clients, including pension and profit sharing
  plans
 
    Current and historical statistics relating to:
 
    --total dollar amount of assets managed
    --Loomis Sayles assets managed in total and by Fund
    --the growth of assets
    --asset types managed
 
  Loomis Sayles Funds' tag line--"Listening Harder, Delivering More" and
statements that and examples of how Loomis Sayles Funds listens to its clients
and works hard to deliver results which exceed their expectations.
 
  References may be included in Loomis Sayles Funds' advertising and
promotional literature about 401(k) and retirement plans that offer the Funds.
The information may include, but is not limited to:
 
    Specific and general references to industry statistics regarding 401(k)
  and retirement plans including historical information and industry trends
  and forecasts regarding the growth of assets, numbers or plans, funding
  vehicles, participants, sponsors and other demographic data relating to
  plans, participants and sponsors, third party and other administrators,
  benefits consultants and firms with whom Loomis Sayles may or may not have
  a relationship.
 
    Specific and general reference to comparative ratings, rankings and other
  forms of evaluation as well as statistics regarding the Fund as 401(k) or
  retirement plan funding vehicles produced by industry authorities, research
  organizations and publications.
 
 
                                      46
<PAGE>
 
Part C.    OTHER INFORMATION
           -----------------

Item 24.   Financial Statements and Exhibits
           ---------------------------------

(a)    Financial statements:  See "Financial Highlights" contained in the
       Prospectus.

(b)    Exhibits:

1.     Agreement and Declaration of Trust. (5)

2.     By-Laws. (5)

3.     Not Applicable.

4.     Not Applicable.

5(a).  Form of Advisory Agreement.

5(b).  Form of Amendment No. 1 to Advisory Agreement between the Trust and
       Loomis Sayles Core Value Fund.(3)

5(c).  Form of Amendment No. 1 to Advisory Agreement between the Trust and
       Loomis Sayles Global Bond Fund.(3)

5(d).  Form of Amendment No. 1 to Advisory Agreement between the Trust and  
       Loomis Sayles Growth Fund.(3)

5(e).  Form of Advisory Agreement between the Trust and Loomis Sayles High 
       Yield Fund.(2)

5(f).  Form of Advisory Agreement between the Trust and Loomis Sayles High
       Yield Fund II.(6)

5(g).  Form of Amendment No. 1 to Advisory Agreement between the Trust and
       Loomis Sayles Intermediate Maturity Bond Fund.(3)

5(h).  Form of Amendment No. 1 to Advisory Agreement between the Trust and
       Loomis Sayles International Equity Fund.(3)

5(i).  Form of Advisory Agreement between the Trust and Loomis Sayles
       Investment Grade Bond Fund.(3)

5(j).  Form of Advisory Agreement between the Trust and Loomis Sayles Managed
       Bond Fund.(5)
<PAGE>
 
5(k).  Form of Advisory Agreement between the Trust and Loomis Sayles Mid-Cap
       Growth Fund.(3)

5(l).  Form of Advisory Agreement between the Trust and Loomis Sayles Mid-Cap
       Value Fund.(3)

5(m).  Form of Amendment No. 1 to Advisory Agreement between the Trust and
       Loomis Sayles Municipal Bond Fund.(3)

5(n).  Form of Amendment No. 1 to Advisory Agreement between the Trust and
       Loomis Sayles Short-Term Bond Fund.(3)

5(o).  Form of Advisory Agreement between the Trust and Loomis Sayles Small Cap
       Growth Fund.(3)

5(p).  Form of Amendment No. 1 to Advisory Agreement between the Trust and
       Loomis Sayles Small Cap Value Fund.(3)

5(q).  Form of Advisory Agreement between the Trust and Loomis Sayles Strategic
       Value Fund.(3)

5(r).  Form of Amended and Restated Investment Advisory Agreement between the
       Trust and Loomis Sayles U.S. Government Securities Fund.

5(s).  Form of Amendment No. 1 to Advisory Agreement between the Trust and
       Loomis Sayles Worldwide Fund.(3)

6.     Form of Distribution Agreement.(3)

7.     Not Applicable.

8(a).  Form of Custodian Agreement.(5)

8(b).  Letter Agreement between the Trust and State Street Bank and Trust
       Company relating to the applicability of the Custodian Agreement to
       Loomis Sayles Short-Term Bond Fund.(4)

8(c).  Letter Agreement between the Trust and State Street Bank and Trust
       Company relating to the applicability of the Custodian Agreement to
       Loomis Sayles High Yield Fund.(4)

8(d).  Letter Agreement between the Trust and State Street Bank and Trust
       Company relating to the applicability of the Custodian Agreement to
       Loomis Sayles Intermediate Maturity Bond Fund, Loomis Sayles Investment
       Grade Bond Fund, Loomis Sayles Mid-Cap Growth Fund, Loomis Sayles Mid-
       Cap Value Fund, Loomis Sayles Small Cap Growth Fund and Loomis Sayles
       Strategic Value Fund.(4)
<PAGE>
 
8(e).   Form of Letter Agreement between the Trust and State Street Bank and
        Trust Company relating to the applicability of the Custodian Agreement
        to Loomis Sayles Worldwide Fund.(4)

8(f).   Form of Letter Agreement between the Trust and State Street Bank and
        Trust Company relating to the applicability of the Custodian Agreement
        to Loomis Sayles Managed Bond Fund.

9(a).   Form of Transfer Agency and Service Agreement between the Trust and
        State Street Bank and Trust Company (5)

9(b).   Letter Agreement between the Trust and State Street Bank and Trust
        Company relating to the applicability of the Transfer Agency and Service
        Agreement to Loomis Sayles Short-Term Bond Fund.(4)

9(c).   Letter Agreement between the Trust and State Street Bank and Trust
        Company relating to the applicability of the Transfer Agency and Service
        Agreement to Loomis Sayles High Yield Fund and Loomis Sayles Worldwide
        Fund.(4)

9(d).   Letter Agreement between the Trust and State Street Bank and Trust
        Company relating to the applicability of the Transfer Agency and Service
        Agreement to Loomis Sayles Intermediate Maturity Bond Fund, Loomis
        Sayles Investment Grade Bond Fund, Loomis Sayles Mid-Cap Growth Fund,
        Loomis Sayles Mid-Cap Value Fund, Loomis Sayles Small Cap Growth Fund
        and Loomis Sayles Strategic Value Fund.(4)

9(e).   Transfer Agency and Service Agreement between the Trust on behalf of the
        Loomis Sayles Managed Bond Fund and State Street Bank and Trust Company.

10(a).  Opinion and Consent of Counsel.(3)

10(b).  Form of Opinion and Consent of Counsel relating to Loomis Sayles
        Managed Bond Fund and Loomis Sayles High Yield Fund II.(6)

11.     Consent of PricewaterhouseCoopers LLP.

12.     Not Applicable.

13(a).  Investment Representation Regarding Initial Shares.(5)

13(b).  Form of Organizational Expense Reimbursement Agreement.(5)

14.     Form of IRA prototype documents.(5)

15(a).  Form of Distribution Plan - Retail Class.(3)

15(b).  Form of Distribution Plan - Admin Class.(5)
 
<PAGE>
 
15(c).  Form of Service and Distribution Plan relating to Loomis Sayles Managed
        Bond Fund and Loomis Sayles High Yield Fund II. (6)

16.     Schedule for Performance Computations.(3)

17(a).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Growth Fund.

17(b).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Core Value Fund.

17(c).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Small Cap Value Fund.

17(d).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        International Equity Fund.

17(e).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Worldwide Fund.

17(f).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Bond Fund.

17(g).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Global Bond Fund.

17(h).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        U.S. Government Securities Fund.

17(I).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Municipal Bond Fund.

17(j).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Short-Term Bond Fund.

17(k).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        High Yield Fund.

17(l).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Intermediate Maturity Bond Fund.

17(m).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Investment Grade Bond Fund.

17(n).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Mid-Cap Growth Fund.

17(o).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Mid-Cap Value Fund.
<PAGE>
 
17(p).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Small Cap Growth Fund.

17(q).  Financial Data Schedule for Institutional Class shares of Loomis Sayles
        Strategic Value Fund.

17(r).  Financial Data Schedule for Retail Class shares of Loomis Sayles Growth
        Fund.

17(s).  Financial Data Schedule for Retail Class shares of Loomis Sayles Core
        Value Fund.

17(t).  Financial Data Schedule for Retail Class shares of Loomis Sayles Small
        Cap Value Fund.

17(u).  Financial Data Schedule for Retail Class shares of Loomis Sayles
        International Equity Fund.

17(v).  Financial Data Schedule for Retail Class shares of Loomis Sayles
        Worldwide Fund.

17(w).  Financial Data Schedule for Retail Class shares of Loomis Sayles Bond
        Fund.

17(x).  Financial Data Schedule for Retail Class shares of Loomis Sayles Global
        Bond Fund.

17(y).  Financial Data Schedule for Retail Class shares of Loomis Sayles Short-
        Term Bond Fund.

17(z).  Financial Data Schedule for Retail Class shares of Loomis Sayles High
        Yield Fund.

17(aa). Financial Data Schedule for Retail Class shares of Loomis Sayles
        Intermediate Maturity Bond Fund.

17(bb). Financial Data Schedule for Retail Class shares of Loomis Sayles
        Investment Grade Bond Fund.

17(cc). Financial Data Schedule for Retail Class shares of Loomis Sayles Mid-
        Cap Growth Fund.

17(dd). Financial Data Schedule for Retail Class shares of Loomis Sayles Mid-Cap
        Value Fund.

17(ee). Financial Data Schedule for Retail Class shares of Loomis Sayles Small
        Cap Growth Fund.

17(ff). Financial Data Schedule for Retail Class shares of Loomis Sayles
        Strategic Value Fund.

17(gg). Financial Data Schedule for Admin Class shares of Loomis Sayles Bond
        Fund.
<PAGE>
 
17(hh)  Financial Data Schedule for Admin Class shares of Loomis Sayles Small
        Cap Value Fund.

18.     Amended and Restated Rule 18f-3(d) Plan. (5)

19.     Powers of Attorney.(1)
        --------------------

(1)     Incorporated by reference to the similarly numbered Exhibit to Post-
        Effective Amendment No. 7 to the Trust's Registration Statement under
        the Securities Act of 1933 filed with the Commission on February 16,
        1996.

(2)     Incorporated by reference to the similarly numbered Exhibit to Post-
        Effective Amendment No. 10 to the Trust Registration Statement under the
        Securities Act of 1933 filed with the Commission on August 30, 1996.

(3)     Incorporated by reference to the similarly numbered Exhibit to Post-
        Effective Amendment No. 11 to the Trust's Registration Statement under
        the Securities Act of 1933 filed with the Commission on October 9, 1996.

(4)     Incorporated by reference to the similarly numbered Exhibit to Post-
        Effective Amendment No. 12 to the Trust's Registration under the
        Securities Act of 1933 filed with the Commission on March 10, 1997.

(5)     Incorporated by reference to the similarly numbered Exhibit to Post-
        Effective Amendment No. 13 to the Trust's Registration under the
        Securities Act of 1933 filed with the Commission on October 31, 1997.

(6)     Incorporated by reference to the similarly numbered Exhibit to Post-
        Effective Amendment No. 15 to the Trust's Registration under the
        Securities Act of 1933 filed with the Commission on August 5, 1998.


Item 25.   Persons Controlled by or under Common Control with Registrant
           -------------------------------------------------------------

     Not Applicable.

Item 26.   Number of Holders of Securities
           -------------------------------

     No Longer Applicable.

Item 27.   Indemnification
           ---------------
Incorporated by reference to Item 27 of Post-Effective Amendment No. 1 to this
Registration Statement filed on November 7, 1991.
<PAGE>
 
Item 28.   Business and Other Connections of Investment Adviser
           ----------------------------------------------------

(a)  Loomis, Sayles & Company, L.P. ("Loomis Sayles"), the adviser of the
Registrant, provides investment advice to the seven series of Loomis Sayles
Investment Trust, six series of New England Funds Trust I, one series of New
England Funds Trust II, one series of New England Funds Trust III, and two
series of New England Zenith Funds, all of which are  registered investment
companies, and to other registered investment companies, organizations and
individuals.

The sole general partner of Loomis Sayles is Loomis, Sayles & Company,
Incorporated, One Financial Center, Boston, Massachusetts 02111.

Item 29.   Principal Underwriters
           ----------------------
The Trust's principal underwriter is Loomis Sayles Distributors,  L.P., the sole
general partner of which is Loomis Sayles Distributors, Incorporated.

Item 30.   Location of Accounts and Records
           --------------------------------

The following companies maintain possession of the documents required by the
specified rules:

(a) Registrant
Rule 31a-1(b)(4), (9), (10), (11)
Rule 31a-2(a)

(b) State Street Bank and Trust Company
225 Franklin Street
Boston, MA 02110
Rule 31a-1(a)
Rule 31a-1(b)(1), (2), (3), (5), (6), (7), (8)
Rule 31a-2(a)

(c) Loomis, Sayles & Company, L.P.
One Financial Center
Boston, MA  02111
Rule 31a-1(f)
Rule 31a-2(e)

(d) Loomis, Sayles Distributors, L.P.
One Financial Center
Boston, MA 02111
Rule 31a-1(d)
Rule 31a-2(c)
<PAGE>
 
Item 31.   Management Services
           -------------------

Not applicable.

Item 32.   Undertakings
           ------------

(I)     The Registrant undertakes to comply with Section 16(c) of the
        Investment Company Act of 1940 as though such provisions of the Act were
        applicable to the Registrant.

(ii)    The Registrant undertakes to furnish each person to whom a prospectus is
        delivered a copy of Registrant's most recent annual report upon request
        and without charge.

********************
NOTICE


A copy of the Agreement and Declaration of Trust of Loomis Sayles Funds (the
"Trust") is on file with the Secretary of State of The Commonwealth of
Massachusetts and notice is hereby given that this Registration Statement has
been executed on behalf of the Trust by an officer of the Trust as an officer
and by its Trustees as trustees and not individually and the obligations of or
arising out of this Registration Statement are not binding upon any of the
Trustees, officers or shareholders individually but are binding only upon the
assets and property of the Trust.
<PAGE>

 
SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment
Company Act of 1940, the Registrant certifies that it meets all of the
requirements for effectiveness of this Registration Statement pursuant to Rule
485(b) under the Securities Act of 1933 and has duly caused this amendment to
its registration statement to be signed on its behalf by the undersigned,
thereunto duly authorized, in the City of Boston, in The Commonwealth of
Massachusetts on the 30th day of November, 1998.

LOOMIS SAYLES FUNDS

By: DANIEL J. FUSS*
- -----------------------------
Daniel J. Fuss, President

Pursuant to the requirements of the Securities Act of 1933 and the Investment
Company Act of 1940, this amendment to the Registration Statement of Loomis
Sayles Funds has been signed below by the following persons in the capacities
and on the date indicated.
 
Signature                                 Title
- ---------                                 -----

DANIEL J. FUSS*                           President and Trustee
- -------------------------------                           
Daniel J. Fuss

MARK W. HOLLAND*                          Treasurer
- ------------------------            
Mark W. Holland

EARL W. FOELL*                            Trustee
- -----------------------------          
Earl W. Foell

RICHARD S. HOLWAY*                        Trustee
- ------------------------          
Richard S. Holway

MICHAEL T. MURRAY*                        Trustee
- ------------------------          
Michael T. Murray

*By :
/s/MARK W. HOLLAND
- ---------------------
Mark W. Holland, for himself and as Attorney-in-fact
November 30, 1998
<PAGE>
 
EXHIBIT INDEX
EXHIBIT NO.
- -------------
5(a)   Form of Advisory Agreement.

5(r).  Form of Amended and Restated Advisory Agreement between the Trust and
       Loomis Sayles U.S. Government Securities Fund.
 
8(f).  Form of Letter Agreement between the Trust and State Street Bank and
       Trust Company relating to the applicability of the Custodian Agreement to
       Loomis Sayles Managed Bond Fund.
 
9(e).  Transfer Agency and Service Agreement between the Trust on behalf of
       Loomis Sayles Managed Bond Fund and State Street Bank and Trust Company.

11.    Consent of PricewaterhouseCoopers LLP
 
17(a). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Growth Fund.
       
17(b). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Core Value Fund.
                             
17(c). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Small Cap Value Fund.
                             
17(d). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       International Equity Fund.
                             
17(e). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Worldwide Fund.
                             
17(f). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Bond Fund.
                             
17(g). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Global Bond Fund.
                              
17(h). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       U.S.Government Securities Fund.
                             
17(I). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Municipal Bond Fund.
                             
17(j). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Short-Term Bond Fund.
                             
17(k). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       High Yield Fund.
<PAGE>
 
17(l). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Intermediate Maturity Bond Fund.

17(m). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Investment Grade Bond Fund.

17(n). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Mid-Cap Growth Fund.

17(o). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Mid-Cap Value Fund.

17(p). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Small Cap Growth Fund.

17(q). Financial Data Schedule for Institutional Class shares of Loomis Sayles
       Strategic Value Fund.

17(r). Financial Data Schedule for Retail Class shares of Loomis Sayles Growth
       Fund.

17(s). Financial Data Schedule for Retail Class shares of Loomis Sayles Core
       Value Fund.

17(t). Financial Data Schedule for Retail Class shares of Loomis Sayles Small
       Cap Value Fund.

17(u). Financial Data Schedule for Retail Class shares of Loomis Sayles
       International Equity Fund.
       
17(v). Financial Data Schedule for Retail Class shares of Loomis Sayles
       Worldwide Fund.
       
17(w). Financial Data Schedule for Retail Class shares of Loomis Sayles Bond
       Fund.
       
17(x). Financial Data Schedule for Retail Class shares of Loomis Sayles Global
       Bond Fund.
       
17(y). Financial Data Schedule for Retail Class shares of Loomis Sayles Short-
       Term Bond Fund.
       
17(z). Financial Data Schedule for Retail Class shares of Loomis Sayles High
       Yield Fund.

17(aa). Financial Data Schedule for Retail Class shares of Loomis Sayles
        Intermediate Maturity Bond Fund.

17(bb). Financial Data Schedule for Retail Class shares of Loomis Sayles
        Investment Grade Bond Fund.

17(cc). Financial Data Schedule for Retail Class shares of Loomis Sayles Mid-Cap
        Growth Fund.
<PAGE>
 
17(dd). Financial Data Schedule for Retail Class shares of Loomis Sayles Mid-Cap
        Value Fund.

17(ee). Financial Data Schedule for Retail Class shares of Loomis Sayles Small
        Cap Growth Fund.

17(ff). Financial Data Schedule for Retail Class shares of Loomis Sayles
        Strategic Value Fund.

17(gg)  Financial Data Schedule for Admin Class shares of Loomis Sayles Bond
        Fund.

17(hh)  Financial Data Schedule for Admin Class shares of Loomis Sayles Small
        Cap Value Fund.

<PAGE>
 
                                                                    Exhibit 5(a)

                              ADVISORY AGREEMENT
                              ------------------

     AGREEMENT made this 30th day of August, 1996, by and between Loomis Sayles
Funds, a Massachusetts business trust (the "Trust"), with respect to its Bond
Fund series (the "Series"), and Loomis, Sayles & Company, L.P., a Delaware
limited partnership (the "Adviser").

                                  WITNESSETH:

     WHEREAS, the Trust and the Adviser wish to enter into an agreement setting
forth the terms upon which the Adviser will perform certain services for the
Series;

     NOW THEREFORE, in consideration of the premises and covenants hereinafter
contained, the parties agree as follows:

     1.  The Trust hereby employs the Adviser to manage the investment and
reinvestment of the assets belonging to the Series and to perform the other
services herein set forth, subject to the supervision of the Board of Trustees
of the Trust.  The Adviser hereby accepts such employment and agrees, at its own
expense, to render the services and to assume the obligations herein set forth,
for the compensation herein provided.  The Adviser shall for all purposes herein
be deemed to be an independent contractor and shall, unless otherwise expressly
provided or authorized, have no authority to act for or represent the Trust in
any way or otherwise be deemed an agent of the Trust.

     2.  In carrying out its obligations to manage the investment and
reinvestment of the assets belonging to the Series, the Adviser shall:

         (a) obtain and evaluate such economic, statistical and financial data
     and information and undertake such additional investment research as it
     shall believe necessary or advisable for the management of the investment
     and reinvestment of the assets belonging to the Series in accordance with
     the Series' investment objective and policies;

         (b) take such steps as are necessary to implement the investment
     policies of the Series by purchase and sale of securities, including the
     placing of orders for such purchase and sale; and

         (c) regularly report to the Board of Trustees with respect to the
     implementation of the investment policies of the Series.

     3.  All activities in connection with the management of the affairs of the
Series undertaken by the Adviser pursuant to this Agreement shall at all times
be subject to the supervision and control of the Board of Trustees, any duly
constituted committee thereof or 
<PAGE>
 
any officer of the Trust acting pursuant to like authority.

     4.  In addition to performing at its expense the obligations set forth in
section 2 hereof, the Adviser shall furnish to the Trust at the Adviser's own
expense or pay the expenses of the Trust for the following:

         (a)  office space in such place or places as may be agreed upon from
     time to time, and all necessary office supplies, facilities and equipment;

         (b) necessary executive and other personnel for managing the affairs
     of the Series (exclusive of those related to and to be performed under
     contract for custodial, transfer, dividend and plan agency services by the
     entity or entities selected to perform such services and exclusive of any
     managerial functions described in section 5); and

         (c) compensation, if any, of Trustees of the Trust who are directors,
     officers, partners or employees of the Adviser or any affiliated person
     (other than a registered investment company) of the Adviser.

     5.  Except as the Adviser may otherwise agree from time to time, nothing
in section 4 hereof shall require the Adviser to bear, or to reimburse the Trust
for:

         (a) any of the costs of printing and distributing the items referred
     to in subsection (n) of this section 5;

         (b) any of the costs of preparing, printing and distributing sales
     literature;

         (c) compensation of Trustees of the Trust who are not directors,
     officers, partners or employees of the Adviser or of any affiliated person
     (other than a registered investment company) of the Adviser;

         (d) registration, filing and other fees in connection with
     requirements of regulatory authorities;

         (e) the charges and expenses of the custodian appointed by the Trust
     for custodial, paying agent, transfer agent and plan agent services;

         (f) charges and expenses of independent accountants retained by the
     Trust;

         (g) charges and expenses of any transfer agents and registrars
     appointed by the Trust;

         (h) brokers' commissions and issue and transfer taxes chargeable to
     the Trust in connection with securities transactions to which the Trust is
     a party;

                                      -2-
<PAGE>
 
         (i) taxes and fees payable by the Trust to Federal, State or other
     governmental agencies;
 
         (j) any cost of certificates representing shares of the Series;

         (k) legal fees and expenses in connection with the affairs of the
     Trust including registering and qualifying its shares with Federal and
     State regulatory authorities;

         (l) expenses of meetings of shareholders and Trustees of the Trust;

         (m) interest, including interest on borrowings by the Trust;

         (n) the cost of services, including services of counsel, required in
     connection with the preparation of the Trust's registration statements and
     prospectuses, including amendments and revisions thereto, annual,
     semiannual and other periodic reports of the Trust, and notices and proxy
     solicitation material furnished to shareholders of the Trust or regulatory
     authorities; and

         (o) the Trust's expenses of bookkeeping, accounting, auditing and
     financial reporting, including related clerical expenses.

     6.  The services of the Adviser to the Trust hereunder are not to be
deemed exclusive and the Adviser shall be free to render similar services to
others, so long as its services hereunder are not impaired thereby.

     7.  As full compensation for all services rendered, facilities furnished
and expenses borne by the Adviser hereunder, the Trust shall pay the Adviser
compensation at the annual percentage rate of .60%, or such lesser rate as the
Adviser may agree to from time to time.  Such compensation shall be payable
monthly in arrears or at such other intervals, not less frequently than
quarterly, as the Board of Trustees of the Trust may from time to time determine
and specify in writing to the Adviser.  The Adviser hereby acknowledges that the
Trust's obligation to pay such compensation is binding only on the assets and
property belonging to the Series.

     8.  If the total of all ordinary business expenses of the Series or the
Trust as a whole (including investment advisory fees but excluding taxes and
portfolio brokerage commissions) for any fiscal year exceeds the lowest
applicable percentage of average net assets or income limitations prescribed by
any state in which shares of the Series are qualified for sale, the Adviser
shall pay any such excess.  Solely for purposes of applying such limitations in
accordance with the foregoing sentence, the Series and the Trust shall each be
deemed to be a separate fund subject to such limitations.  Should the applicable
state limitation provisions fail to specify how the average net assets of the
Trust or belonging to the Series are to be 

                                      -3-
<PAGE>
 
calculated, that figure shall be calculated by reference to the average daily
net assets of the Trust or the Series, as the case may be.

     9.  It is understood that any of the shareholders, trustees, officers,
employees and agents of the Trust may be a partner, shareholder, director,
officer, employee or agent of, or be otherwise interested in, the Adviser, any
affiliated person of the Adviser, any organization in which the Adviser may have
an interest or any organization which may have an interest in the Adviser; that
the Adviser, any such affiliated person or any such organization may have an
interest in the Trust; and that the existence of any such dual interest shall
not affect the validity hereof or of any transactions hereunder except as
otherwise provided in the Agreement and Declaration of Trust of the Trust and
the Partnership Agreement of the Adviser, respectively, or by specific
provisions of applicable law.

     10. This Agreement shall become effective as of the date of its execution,
and

         (a) unless otherwise terminated, this Agreement shall continue in
     effect for two years from the date of execution, and from year to year
     thereafter only so long as such continuance is specifically approved at
     least annually (i) by the Board of Trustees of the Trust or by vote of a
     majority of the outstanding voting securities of the Series,  and (ii) by
     vote of a majority of the Trustees of the Trust who are not interested
     persons of the Trust or the Adviser, cast in person at a meeting called for
     the purpose of voting on such approval;

         (b) this Agreement may at any time be terminated on sixty days'
     written notice to the Adviser either by vote of the Board of Trustees of
     the Trust or by vote of a majority of the outstanding voting securities of
     the Series;

         (c) this Agreement shall automatically terminate in the event of its
     assignment;

         (d) this Agreement may be terminated by the Adviser on ninety days'
     written notice to the Trust;

         (e) if the Adviser requires the Trust or the Series to change its name
     so as to eliminate all references to the words "Loomis" or "Sayles," then
     this Agreement shall automatically terminate at the time of such change
     unless the continuance of this Agreement after such change shall have been
     specifically approved by vote of a majority of the outstanding voting
     securities of the Series and by vote of a majority of the Trustees of the
     Trust who are not interested persons of the Trust or the Adviser, cast in
     person at a meeting called for the purpose of voting on such approval.
 
     Termination of this Agreement pursuant to this section 10 shall be without
payment of any penalty.

                                      -4-
<PAGE>
 
     11. This Agreement may be amended at any time by mutual consent of the
parties, provided that such consent on the part of the Trust shall have been
approved by vote of a majority of the outstanding voting securities of the
Series and by vote of a majority of the Trustees of the Trust who are not
interested persons of the Trust or the Adviser, cast in person at a meeting
called for the purposes of voting on such approval.

     12. For the purposes of this Agreement, the terms "vote of a majority of
the outstanding voting securities," "interested person," "affiliated person" and
"assignment" shall have their respective meanings defined in the Investment
Company Act of 1940 and the rules and regulations thereunder, subject, however,
to such exemptions as may be granted by the Securities and Exchange Commission
under said Act.  References in this Agreement to any assets, property or
liabilities "belonging to" the Series shall have the meaning defined in the
Trust's Agreement and Declaration of Trust and By-Laws as amended from time to
time.

     13. In the absence of willful misfeasance, bad faith or gross negligence
on the part of the Adviser, or reckless disregard of its obligations and duties
hereunder, the Adviser shall not be subject to any liability to the Trust, to
any shareholder of the Trust or to any other person, firm or organization, for
any act or omission in the course of, or connected with, rendering services
hereunder.

                                      -5-
<PAGE>
 
     IN WITNESS WHEREOF, the parties hereto have executed this Agreement on the
day and year first above written.

                                    LOOMIS SAYLES FUNDS,
                                     on behalf of its Bond Fund series

                                             
                                    By:_______________________________
                                       Daniel J. Fuss                      
                                       President                           


                                    LOOMIS, SAYLES & COMPANY, L.P.


                                    By:  LOOMIS, SAYLES & COMPANY,
                                          INC., its general partner


                                    By:_______________________________
                                       Name:
                                       Title:


     A copy of the Agreement and Declaration of Trust establishing the Trust is
on file with the Secretary of State of The Commonwealth of Massachusetts, and
notice is hereby given that this Agreement is executed with respect to the
Trust's Bond Fund series on behalf of the Trust by officers of the Trust as
officers and not individually and that the obligations of or arising out of this
Agreement are not binding upon any of the Trustees, officers or shareholders
individually but are binding only upon the assets and property belonging to the
Series.

                                      -6-

<PAGE>
 
                                                                    Exhibit 5(r)


                    AMENDED AND RESTATED ADVISORY AGREEMENT
                    ---------------------------------------

     AGREEMENT made this 1st day of December, 1998, by and between Loomis Sayles
Funds, a Massachusetts business trust (the "Trust"), with respect to its U.S.
Government Securities Fund series (the "Series"), and Loomis, Sayles & Company,
L.P., a Delaware limited partnership (the "Adviser").

                                  WITNESSETH:

     WHEREAS, the Trust and the Adviser wish to enter into an agreement setting
forth the terms upon which the Adviser will perform certain services for the
Series;

     NOW THEREFORE, in consideration of the premises and covenants hereinafter
contained, the parties agree as follows:

     1.  The Trust hereby employs the Adviser to manage the investment and
reinvestment of the assets belonging to the Series and to perform the other
services herein set forth, subject to the supervision of the Board of Trustees
of the Trust.  The Adviser hereby accepts such employment and agrees, at its own
expense, to render the services and to assume the obligations herein set forth,
for the compensation herein provided.  The Adviser shall for all purposes herein
be deemed to be an independent contractor and shall, unless otherwise expressly
provided or authorized, have no authority to act for or represent the Trust in
any way or otherwise be deemed an agent of the Trust.

     2.  In carrying out its obligations to manage the investment and
reinvestment of the assets belonging to the Series, the Adviser shall:

         (a) obtain and evaluate such economic, statistical and financial data
     and information and undertake such additional investment research as it
     shall believe necessary or advisable for the management of the investment
     and reinvestment of the assets belonging to the Series in accordance with
     the Series' investment objective and policies;

         (b) take such steps as are necessary to implement the investment
     policies of the Series by purchase and sale of securities, including the
     placing of orders for such purchase and sale; and

         (c) regularly report to the Board of Trustees with respect to the
     implementation of the investment policies of the Series.
<PAGE>
 
     3.  All activities in connection with the management of the affairs of the
Series undertaken by the Adviser pursuant to this Agreement shall at all times
be subject to the supervision and control of the Board of Trustees, any duly
constituted committee thereof or any officer of the Trust acting pursuant to
like authority.

     4.  In addition to performing at its expense the obligations set forth in
section 2 hereof, the Adviser shall furnish to the Trust at the Adviser's own
expense or pay the expenses of the Trust for the following:

         (a)  office space in such place or places as may be agreed upon from
     time to time, and all necessary office supplies, facilities and equipment;

         (b)  necessary executive and other personnel for managing the affairs
     of the Series (exclusive of those related to and to be performed under
     contract for custodial, transfer, dividend and plan agency services by the
     entity or entities selected to perform such services and exclusive of any
     managerial functions described in section 5); and

         (c)  compensation, if any, of Trustees of the Trust who are directors,
     officers, partners or employees of the Adviser or any affiliated person
     (other than a registered investment company) of the Adviser.

     5.  Except as the Adviser may otherwise agree from time to time, nothing in
section 4 hereof shall require the Adviser to bear, or to reimburse the Trust
for:

         (a)  any of the costs of printing and distributing the items referred
     to in subsection (n) of this section 5;

         (b)  any of the costs of preparing, printing and distributing sales
     literature;

         (c)  compensation of Trustees of the Trust who are not directors,
     officers, partners or employees of the Adviser or of any affiliated person
     (other than a registered investment company) of the Adviser;

         (d)  registration, filing and other fees in connection with
     requirements of regulatory authorities;

         (e)  the charges and expenses of the custodian appointed by the Trust
     for custodial, paying agent, transfer agent and plan agent services;

         (f)  charges and expenses of independent accountants retained by the
     Trust;

         (g)  charges and expenses of any transfer agents and registrars
     appointed by the Trust;

                                      -2-
<PAGE>
 
          (h) brokers' commissions and issue and transfer taxes chargeable to
     the Trust in connection with securities transactions to which the Trust is
     a party;

          (i) taxes and fees payable by the Trust to Federal, State or other
     governmental agencies;

          (j) any cost of certificates representing shares of the Series;

          (k) legal fees and expenses in connection with the affairs of the
     Trust including registering and qualifying its shares with Federal and
     State regulatory authorities;

          (l) expenses of meetings of shareholders and Trustees of the Trust;

          (m) interest, including interest on borrowings by the Trust;

          (n) the cost of services, including services of counsel, required in
     connection with the preparation of the Trust's registration statements and
     prospectuses, including amendments and revisions thereto, annual,
     semiannual and other periodic reports of the Trust, and notices and proxy
     solicitation material furnished to shareholders of the Trust or regulatory
     authorities; and

          (o) the Trust's expenses of bookkeeping, accounting, auditing and
     financial reporting, including related clerical expenses.

     6.  The services of the Adviser to the Trust hereunder are not to be deemed
exclusive and the Adviser shall be free to render similar services to others, so
long as its services hereunder are not impaired thereby.

     7.  As full compensation for all services rendered, facilities furnished
and expenses borne by the Adviser hereunder, the Trust shall pay the Adviser
compensation at the annual percentage rate of .30%, or such lesser rate as the
Adviser may agree to from time to time.  Such compensation shall be payable
monthly in arrears or at such other intervals, not less frequently than
quarterly, as the Board of Trustees of the Trust may from time to time determine
and specify in writing to the Adviser.  The Adviser hereby acknowledges that the
Trust's obligation to pay such compensation is binding only on the assets and
property belonging to the Series.

     8.  If the total of all ordinary business expenses of the Series or the
Trust as a whole (including investment advisory fees but excluding taxes and
portfolio brokerage commissions) for any fiscal year exceeds the lowest
applicable percentage of average net assets or income limitations prescribed by
any state in which shares of the Series are qualified for sale, the Adviser
shall pay any such excess.  Solely for purposes of applying such limitations

                                      -3-
<PAGE>
 
in accordance with the foregoing sentence, the Series and the Trust shall each
be deemed to be a separate fund subject to such limitations. Should the
applicable state limitation provisions fail to specify how the average net
assets of the Trust or belonging to the Series are to be calculated, that figure
shall be calculated by reference to the average daily net assets of the Trust or
the Series, as the case may be.

     9.  It is understood that any of the shareholders, trustees, officers,
employees and agents of the Trust may be a partner, shareholder, director,
officer, employee or agent of, or be otherwise interested in, the Adviser, any
affiliated person of the Adviser, any organization in which the Adviser may have
an interest or any organization which may have an interest in the Adviser; that
the Adviser, any such affiliated person or any such organization may have an
interest in the Trust; and that the existence of any such dual interest shall
not affect the validity hereof or of any transactions hereunder except as
otherwise provided in the Agreement and Declaration of Trust of the Trust and
the Partnership Agreement of the Adviser, respectively, or by specific
provisions of applicable law.

     10. This Agreement shall become effective as of the date of its execution,
and

         (a)  unless otherwise terminated, this Agreement shall continue in
     effect for two years from the date of execution, and from year to year
     thereafter only so long as such continuance is specifically approved at
     least annually (i) by the Board of Trustees of the Trust or by vote of a
     majority of the outstanding voting securities of the Series,  and (ii) by
     vote of a majority of the Trustees of the Trust who are not interested
     persons of the Trust or the Adviser, cast in person at a meeting called for
     the purpose of voting on such approval;

         (b)  this Agreement may at any time be terminated on sixty days'
     written notice to the Adviser either by vote of the Board of Trustees of
     the Trust or by vote of a majority of the outstanding voting securities of
     the Series;

         (c)  this Agreement shall automatically terminate in the event of its
     assignment;

         (d)  this Agreement may be terminated by the Adviser on ninety days'
     written notice to the Trust;

         (e)  if the Adviser requires the Trust or the Series to change its name
     so as to eliminate all references to the words "Loomis" or "Sayles," then
     this Agreement shall automatically terminate at the time of such change
     unless the continuance of this Agreement after such change shall have been
     specifically approved by vote of a majority of the outstanding voting
     securities of the Series and by vote of a majority of the Trustees of the
     Trust who are not interested persons of the Trust or the Adviser, cast in
     person at a meeting called for the purpose of voting on such approval.

                                      -4-
<PAGE>
 
     Termination of this Agreement pursuant to this section 10 shall be without
payment of any penalty.

     11.  This Agreement may be amended at any time by mutual consent of the
parties, provided that such consent on the part of the Trust shall have been
approved by vote of a majority of the outstanding voting securities of the
Series and by vote of a majority of the Trustees of the Trust who are not
interested persons of the Trust or the Adviser, cast in person at a meeting
called for the purposes of voting on such approval.

     12.  For the purposes of this Agreement, the terms "vote of a majority of
the outstanding voting securities," "interested person," "affiliated person" and
"assignment" shall have their respective meanings defined in the Investment
Company Act of 1940 and the rules and regulations thereunder, subject, however,
to such exemptions as may be granted by the Securities and Exchange Commission
under said Act.  References in this Agreement to any assets, property or
liabilities "belonging to" the Series shall have the meaning defined in the
Trust's Agreement and Declaration of Trust and By-Laws as amended from time to
time.

     13.  In the absence of willful misfeasance, bad faith or gross negligence
on the part of the Adviser, or reckless disregard of its obligations and duties
hereunder, the Adviser shall not be subject to any liability to the Trust, to
any shareholder of the Trust or to any other person, firm or organization, for
any act or omission in the course of, or connected with, rendering services
hereunder.

                                      -5-
<PAGE>
 
     IN WITNESS WHEREOF, the parties hereto have executed this Agreement on the
day and year first above written.


                                    LOOMIS SAYLES FUNDS,
                                     on behalf of its U.S. Government
                                     Securities Fund series


                                    By:_____________________________________
                                       Daniel J. Fuss
                                       President



                                    LOOMIS, SAYLES & COMPANY, L.P.


                                    By: LOOMIS, SAYLES & COMPANY,
                                        INC., its general partner



                                    By:_____________________________
                                       Name:
                                       Title:

     A copy of the Agreement and Declaration of Trust establishing the Trust is
on file with the Secretary of State of The Commonwealth of Massachusetts, and
notice is hereby given that this Agreement is executed with respect to the
Trust's U.S. Government Securities Fund series on behalf of the Trust by
officers of the Trust as officers and not individually and that the obligations
of or arising out of this Agreement are not binding upon any of the Trustees,
officers or shareholders individually but are binding only upon the assets and
property belonging to the Series.

                                      -6-

<PAGE>
 
                                                                    Exhibit 8(f)



                              October 7, 1998

State Street Bank and Trust Company
1776 Heritage Drive
North Quincy, MA 02171

Gentlemen:

     This is to advise you that Loomis Sayles Funds (the "Fund") has established
a new series of shares to be known as Loomis Sayles Managed Bond Fund.  In
accordance with the Additional Funds provision in Section 17 of the Custodian
Contract dated April 23, 1991 between the Fund and State Street Bank and Trust
Company, the Fund hereby requests that you act as Custodian for the new series
under the terms of the respective contract.

     Please indicate your acceptance of the foregoing by executing two copies of
this Letter Agreement, returning one to the Fund and retaining one copy for your
records.


                              LOOMIS SAYLES MANAGED BOND FUND


                              By:_______________________________
                                    Daniel J. Fuss, President


Agreed to this ________ day of October, 1998

STATE STREET BANK AND TRUST COMPANY


By:_______________________
     Vice President

<PAGE>
 
                                                                    Exhibit 9(e)



                     TRANSFER AGENCY AND SERVICE AGREEMENT
                                     
                         
                                    between
                                    

                        LOOMIS SAYLES MANAGED BOND FUND
                                  

                                      and
  

                      STATE STREET BANK AND TRUST COMPANY
<PAGE>
 
                               TABLE OF CONTENTS
                               -----------------

<TABLE> 
<CAPTION> 
                                                                 Page
                                                                 ----
     <S>  <C>                                                    <C>


     1.   Terms of Appointment; Duties of the Bank.............   1

     2.   Fees and Expenses....................................   3

     3.   Representations and Warranties of the Bank...........   4

     4.   Representations and Warranties of the Fund...........   4

     5.   Data Access and Proprietary Information..............   5

     6.   Indemnification......................................   6

     7.   Standard of Care.....................................   7

     8.   Covenants of the Fund and the Bank...................   7

     9.   Termination of Agreement.............................   8

     10.  Assignment...........................................   8

     11.  Amendment............................................   9

     12.  Massachusetts Law to Apply...........................   9

     13.  Force Majeure........................................   9

     14.  Consequential Damages................................   9

     15.  Merger of Agreement..................................   9

     16.  Limitations of Liability of the Trustees
          or Shareholders......................................   9

     17.  Counterparts.........................................  10

     18.  Reproduction of Documents............................  10
</TABLE> 
<PAGE>
 
                     TRANSFER AGENCY AND SERVICE AGREEMENT
                     -------------------------------------

AGREEMENT made as of the 26th day of August, 1998 by and between Loomis Sayles
Funds, a Massachusetts business trust, having its principal office and place of
business at One International Place, Boston, Massachusetts (the "Fund"), on
behalf of its Loomis Sayles Managed Bond Fund and STATE STREET BANK AND TRUST
COMPANY, a Massachusetts trust company having its principal office and place of
business at 225 Franklin Street, Boston, Massachusetts 02110 (the "Bank").

WHEREAS, the Fund is authorized to issue shares in separate series, with each
such series representing interests in a separate portfolio of securities and
other assets; and

WHEREAS, the Fund intends to initially offer shares in the Loomis Sayles Managed
Bond Fund (the "Portfolio"); and

WHEREAS, the Fund on behalf of the Portfolio desires to appoint the Bank as its
transfer agent, dividend disbursing agent, custodian of certain retirement plans
and agent in connection with certain other activities, and the Bank desires to
accept such appointment.

NOW, THEREFORE, in consideration of the mutual covenants herein contained, the
parties hereto agree as follows:

l.    Terms of Appointment; Duties of the Bank
      ----------------------------------------

1.1   Subject to the terms and conditions set forth in this Agreement, the Fund,
      on behalf of the Portfolio, hereby employs and appoints the Bank to act
      as, and the Bank agrees to act as its transfer agent for the Fund's
      authorized and issued shares of its common stock, $    par value,
      ("Shares"), dividend disbursing agent, custodian of certain retirement
      plans and agent in connection with any accumulation, open-account or
      similar plans provided to the shareholders of the respective Portfolio of
      the Fund ("Shareholders") and set out in the currently effective
      prospectus and statement of additional information ("prospectus") of the
      Fund on behalf of the Portfolio, including without  limitation any
      periodic investment plan or periodic withdrawal program.

1.2   The Bank agrees that it will perform the following services:

      (a)  In accordance with procedures established from time to time by
           agreement between the Fund on behalf of  the Portfolio, as applicable
           and the Bank, the Bank shall:

           (i)   Receive for acceptance, orders for the purchase of Shares, and
                 promptly deliver payment and appropriate documentation thereof
                 to the Custodian of the Fund authorized pursuant to the
                 Declaration of Trust of the Fund (the "Custodian");

           (ii)  Pursuant to purchase orders, issue the appropriate number of
                 Shares and hold such Shares in the appropriate Shareholder
                 account;

           (iii) Receive for acceptance redemption requests and redemption
                 directions and

                                       1
<PAGE>
 
                 deliver the appropriate documentation thereof to the Custodian;

           (iv)  In respect to the transactions in items (i), (ii) and (iii)
                 above, the Bank shall execute transactions directly with 
                 broker-dealers authorized by the Fund who shall thereby be
                 deemed to be acting on behalf of the Fund;

           (v)   At the appropriate time as and when it receives monies paid to
                 it by the Custodian with respect to any redemption, pay over or
                 cause to be paid over in the appropriate manner such monies as
                 instructed by the redeeming Shareholders;

           (vi)  Effect transfers of Shares by the registered owners thereof
                 upon receipt of appropriate instructions;

           (vii) Prepare and transmit payments for dividends and distributions
                 declared by the Fund on behalf of the Portfolio;

          (viii) Issue replacement certificates for those certificates alleged
                 to have been lost, stolen or destroyed upon receipt by the Bank
                 of indemnification satisfactory to the Bank and protecting the
                 Bank and the Fund, and the Bank at its option, may issue
                 replacement certificates in place of mutilated stock
                 certificates upon presentation thereof and without such
                 indemnity;

           (ix)  Maintain records of account for and advise the Fund and its
                 Shareholders as to the foregoing; and

           (x)   Record the issuance of shares of the Fund and maintain pursuant
                 to SEC Rule 17Ad-10(e) a record of the total number of shares
                 of the Fund which are authorized, based upon data provided to
                 it by the Fund, and issued and outstanding. The Bank shall also
                 provide the Fund on a regular basis with the total number of
                 shares which are authorized and issued and outstanding and
                 shall have no obligation, when recording the issuance of
                 shares, to monitor the issuance of such shares or to take
                 cognizance of any laws relating to the issue or sale of such
                 Shares, which functions shall be the sole responsibility of the
                 Fund.

      (b)  In addition to and neither in lieu nor in contravention of the
           services set forth in the above paragraph (a), the Bank shall:  (i)
           perform the customary services of a transfer agent, dividend
           disbursing agent, custodian of certain retirement plans and, as
           relevant, agent in connection with accumulation, open-account or
           similar plans (including without limitation any periodic investment
           plan or periodic withdrawal program), including but not limited to:
           maintaining all Shareholder accounts, preparing Shareholder meeting
           lists, mailing proxies, mailing Shareholder reports and prospectuses
           to current Shareholders, withholding taxes on U.S. resident and non-
           resident alien accounts, preparing and filing U.S. Treasury
           Department Forms 1099 and other appropriate forms required with
           respect to dividends and distributions by federal authorities for all
           Shareholders, preparing and mailing confirmation forms and statements
           of account to Shareholders for all purchases and redemptions of
           Shares and other confirmable transactions in Shareholder accounts,
           preparing and mailing activity statements for Shareholders, and
           providing Shareholder account information and (ii) provide a system
           which will enable the Fund to monitor the total number of Shares sold
           in 

                                       2
<PAGE>
 
           each State.

      (c)  In addition, the Fund shall (i) identify to the Bank in writing those
           transactions and assets to be treated as exempt from blue sky
           reporting for each State and (ii) verify the  establishment of
           transactions for each State on the system prior to activation and
           thereafter monitor the daily activity for each State.  The
           responsibility of the Bank for the Fund's blue sky State registration
           status is solely limited to the initial establishment of transactions
           subject to blue sky compliance by the Fund and the reporting of such
           transactions to the Fund as provided above.

      (d)  Procedures as to who shall provide certain of these services in
           Section 1 may be established from time to time by agreement between
           the Fund on behalf of the Portfolio and the Bank per the attached
           service responsibility schedule.  The Bank may at times perform only
           a portion of these services and the Fund or its agent may perform
           these services on the Fund's behalf.

      (e)  The Bank shall provide additional services on behalf of the Fund
           (i.e., escheatment services) which may be agreed upon in writing
           between the Fund and the Bank.

2.    Fees and Expenses
      -----------------

2.1   For the performance by the Bank pursuant to this Agreement, the Fund
      agrees on behalf of the Portfolio to pay the Bank an annual maintenance
      fee for each Shareholder account as set out in the initial fee schedule
      attached hereto.  Such fees and out-of-pocket expenses and advances
      identified under Section 2.2 below may be changed from time to time
      subject to mutual written agreement between the Fund and the Bank.

2.2   In addition to the fee paid under Section 2.1 above, the Fund agrees on
      behalf of the Portfolio to reimburse the Bank for out-of-pocket expenses,
      including but not limited to confirmation production,  postage, forms,
      telephone, microfilm, microfiche, tabulating proxies, records storage, or
      advances incurred by the Bank for the items set out in the fee schedule
      attached hereto. In addition, any other expenses incurred by the Bank at
      the request or with the consent of the Fund, will be reimbursed by the
      Fund on behalf of the applicable Portfolio.

2.3   The Fund agrees on behalf of the Portfolio to pay all fees and
      reimbursable expenses within five days following the receipt of the
      respective billing notice.  Postage for mailing of dividends, proxies,
      Fund reports and other mailings to all shareholder accounts shall be
      advanced to the Bank by the Fund at least seven (7) days prior to the
      mailing date of such materials.

3.    Representations and Warranties of the Bank
      ------------------------------------------

The Bank represents and warrants to the Fund that:

3.1   It is a trust company duly organized and existing and in good standing
      under the laws of the Commonwealth of Massachusetts.

3.2   It is duly qualified to carry on its business in the Commonwealth of
      Massachusetts.

3.3   It is empowered under applicable laws and by its Charter and By-Laws to
      enter into and perform this Agreement.

                                       3
<PAGE>
 
3.4   All requisite corporate proceedings have been taken to authorize it to
      enter into and perform this Agreement.

3.5   It has and will continue to have access to the necessary facilities,
      equipment and personnel to perform its duties and obligations under this
      Agreement.

4.    Representations and Warranties of the Fund
      ------------------------------------------

The Fund represents and warrants to the Bank that:

4.1   It is a business trust duly organized and existing and in good standing
      under the laws of the State of.

4.2   It is empowered under applicable laws and by its Declaration of Trust and
      By-Laws to enter into and perform this Agreement.

4.3   All corporate proceedings required by said Declaration of Trust and By-
      Laws have been taken to authorize it to enter into and perform this
      Agreement.

4.4   It is an open-end and diversified management investment company registered
      under the Investment Company Act of 1940, as amended.

4.5   A registration statement under the Securities Act of 1933, as amended on
      behalf of the Portfolio is currently effective and will remain effective,
      and appropriate state securities law filings have been made and will
      continue to be made, with respect to all Shares of the Fund being offered
      for sale.

5.    Data Access and Proprietary Information
      ---------------------------------------

5.1   The Fund acknowledges that the data bases, computer programs, screen
      formats, report formats, interactive design techniques, and documentation
      manuals furnished to the Fund by the Bank as part of the Fund's ability to
      access certain Fund-related data ("Customer Data") maintained by the Bank
      on data bases under the control and ownership of the Bank or other third
      party ("Data Access Services") constitute copyrighted, trade secret, or
      other proprietary information (collectively, "Proprietary Information") of
      substantial value to the Bank or other third party.  In no event shall
      Proprietary Information be  deemed Customer Data.  The Fund agrees to
      treat all Proprietary Information as proprietary to the Bank and further
      agrees that it shall not divulge any Proprietary Information to any person
      or organization except as may be provided hereunder.  Without limiting the
      foregoing, the Fund agrees for itself and its employees and agents:

      (a)  to access Customer Data solely from locations as may be designated in
           writing by the Bank and solely in accordance with the Bank's
           applicable user documentation;

      (b)  to refrain from copying or duplicating in any way the Proprietary
           Information;

      (c)  to refrain from obtaining unauthorized access to any portion of the
           Proprietary Information, and if such access is inadvertently
           obtained, to inform in a timely manner of such fact and dispose of
           such information in accordance with the Bank's instructions;

                                       4
<PAGE>
 
      (d)  to refrain from causing or allowing the data acquired hereunder from
           being retransmitted to any other computer facility or other location,
           except with the prior written consent of the Bank;

      (e)  that the Fund shall have access only to those authorized transactions
           agreed upon by the parties;

      (f)  to honor all reasonable written requests made by the Bank to protect
           at the Bank's expense the  rights of the Bank in Proprietary
           Information at common law, under federal copyright law and under
           other federal or state law.

Each party shall take reasonable efforts to advise its employees of their
obligations pursuant to this Section 5.  The obligations of this Section shall
survive any earlier termination of this Agreement.

5.2   If the Fund notifies the Bank that any of the Data Access Services do not
      operate in material compliance with the most recently issued user
      documentation for such services, the Bank shall endeavor in a timely
      manner to correct such failure. Organizations from which the Bank may
      obtain certain data included in the Data Access Services are solely
      responsible for the contents of such data and the Fund agrees to make no
      claim against the Bank arising out of the contents of such third-party
      data, including, but not limited to, the accuracy thereof. DATA ACCESS
      SERVICES AND ALL COMPUTER PROGRAMS AND SOFTWARE SPECIFICATIONS USED IN
      CONNECTION THEREWITH ARE PROVIDED ON AN AS IS, AS AVAILABLE BASIS. THE
      BANK EXPRESSLY DISCLAIMS ALL WARRANTIES EXCEPT THOSE EXPRESSLY STATED
      HEREIN INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
      MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

5.3   If the transactions available to the Fund include the ability to originate
      electronic instructions to the Bank in order to (i) effect the transfer or
      movement of cash or Shares or (ii) transmit Shareholder information or
      other information, then in  such event the Bank shall be entitled to rely
      on the validity and authenticity of such instruction without undertaking
      any further inquiry as long as such instruction is undertaken in
      conformity with security procedures established by the Bank from time to
      time.

6.    Indemnification
      ---------------

6.1   The Bank shall not be responsible for, and the Fund shall on behalf of the
      Portfolio indemnify and hold the Bank harmless from and against, any and
      all losses, damages, costs, charges, counsel fees, payments, expenses and
      liability arising out of or attributable to:

      (a)  All actions of the Bank or its agents or subcontractors required to
           be taken pursuant to this Agreement, provided that such actions are
           taken in good faith and without negligence or willful misconduct.

      (b)  The Fund's lack of good faith, negligence or willful misconduct which
           arise out of the breach of any representation or warranty of the Fund
           hereunder.

      (c)  The reliance on or use by the Bank or its agents or subcontractors of
           information, records, documents or services which (i) are received by
           the Bank or its agents or subcontractors, and (ii) have been
           prepared, maintained or performed by the Fund or any other person or
           firm on behalf of the Fund including but not limited to any 

                                       5
<PAGE>
 
           previous transfer agent or registrar.

      (d)  The reliance on, or the carrying out by the Bank or its agents or
           subcontractors of any instructions or requests of the Fund on behalf
           of the Portfolio.

      (e)  The offer or sale of Shares in violation of any requirement under the
           federal securities laws or regulations or the securities laws or
           regulations of any state that such Shares be registered in such state
           or in violation of any stop order or other determination or ruling by
           any federal agency or any state with respect to the offer or sale of
           such Shares in such state.

      (f)  The negotiation and processing by the Bank of checks not made payable
           to the order of the Bank, the Fund, the Fund=s management company,
           transfer agent or distributor or the retirement account custodian or
           trustee for a plan account investing in Shares, which checks are
           tendered to the Bank for the purchase of Shares (i.e., checks made
           payable to prospective or existing Shareholders, such checks are
           commonly known as Athird party checks@).

6.2   At any time the Bank may apply to any officer of the Fund for
      instructions, and may consult with legal counsel with respect to any
      matter arising in connection with the services to be performed by the Bank
      under this Agreement, and the Bank and its agents or subcontractors shall
      not be liable and shall be indemnified by the Fund on behalf of the
      Portfolio for any action taken or omitted by it in reliance upon such
      instructions or upon the opinion of such counsel.  The Bank, its agents
      and subcontractors shall be protected and indemnified in acting upon any
      paper or document furnished by or on behalf of the Fund, reasonably
      believed to be genuine and to have been signed by the proper person or
      persons, or upon any instruction, information, data, records or documents
      provided the Bank or its agents or subcontractors by machine readable
      input, telex, CRT data entry or other similar means authorized by the
      Fund, and shall not be held to have notice of any change of authority of
      any person, until receipt of written notice thereof from the Fund.  The
      Bank, its agents and subcontractors shall also be protected and
      indemnified in recognizing stock certificates which are reasonably
      believed to bear the proper manual or facsimile signatures of the officers
      of the Fund, and the proper countersignature of any former transfer  agent
      or former registrar, or of a co-transfer agent or co-registrar.

6.3   In order that the indemnification provisions contained in this Section 6
      shall apply, upon the assertion of a claim for which the Fund may be
      required to indemnify the Bank, the Bank shall promptly notify the Fund of
      such assertion, and shall keep the Fund advised with respect to all
      developments concerning such claim.  The Fund shall have the option to
      participate with the Bank in the defense of such claim or to defend
      against said claim in its own name or in the name of the Bank.  The Bank
      shall in no case confess any claim or make any compromise in any case in
      which the Fund may be required to indemnify the Bank except with the
      Fund's prior written consent.

7.    Standard of Care
      ----------------

      The Bank shall at all times act in good faith and agrees to use its best
      efforts within reasonable limits to insure the accuracy of all services
      performed under this Agreement, but assumes no responsibility and shall
      not be liable for loss or damage due to errors unless said errors are
      caused by its negligence, bad faith, or willful misconduct or that of its
      employees.

                                       6
<PAGE>
 
8.    Covenants of the Fund and the Bank
      ----------------------------------

8.1   The Fund shall on behalf of the Portfolio promptly furnish to the Bank the
      following:

      (a)  A certified copy of the resolution of the Board of Trustees of the
           Fund authorizing the appointment of the Bank and the execution and
           delivery of this Agreement.

      (b)  A copy of the Declaration of Trust and By-Laws of the Fund and all
           amendments thereto.

8.2   The Bank hereby agrees to establish and maintain facilities and procedures
      reasonably acceptable to the Fund for safekeeping of stock certificates,
      check forms and facsimile signature imprinting devices, if any; and for
      the preparation or use, and for keeping account of, such certificates,
      forms and devices.

8.3   The Bank shall keep records relating to the services to be performed
      hereunder, in the form and manner as it may deem advisable.  To the extent
      required by Section 31 of the Investment Company Act of 1940, as amended,
      and the Rules thereunder, the Bank agrees that all such records prepared
      or maintained by the Bank relating to the services to be performed by the
      Bank hereunder are the property of the Fund and will be preserved,
      maintained and made available in accordance with such Section and Rules,
      and will be surrendered promptly to the Fund on and in accordance with its
      request.

8.4   The Bank and the Fund agree that all books, records, information and data
      pertaining to the business of the other party which are exchanged or
      received pursuant to the negotiation or the carrying out of this Agreement
      shall remain confidential, and shall not be voluntarily disclosed to any
      other person, except as may be required by law.

8.5   In case of any requests or demands for the inspection of the Shareholder
      records of the Fund, the Bank will endeavor to notify the Fund and to
      secure instructions from an  authorized officer of the Fund as to such
      inspection.  The Bank reserves the right, however, to exhibit the
      Shareholder records to any person whenever it is advised by its counsel
      that it may be held liable for the failure to exhibit the Shareholder
      records to such person.

9.    Termination of Agreement
      ------------------------

9.1   This Agreement may be terminated by either party upon one hundred twenty
      (120) days written notice to the other.

9.2   Should the Fund exercise its right to terminate, all out-of-pocket
      expenses associated with the movement of records and material will be
      borne by the Fund on behalf of the applicable Portfolio(s).  Additionally,
      the Bank reserves the right to charge for any other reasonable expenses
      associated with such termination and/or a charge equivalent to the average
      of three (3) months' fees.

10.   Assignment
      ----------

10.1  Except as provided in Section 11.3 below, neither this Agreement nor any
      rights or obligations hereunder may be assigned by either party without
      the written consent of the 

                                       7
<PAGE>
 
      other party.

10.2  This Agreement shall inure to the benefit of and be binding upon the
      parties and their respective permitted successors and assigns.

10.3  The Bank may, without further consent on the part of the Fund, subcontract
      for the performance hereof with (i) Boston Financial Data Services, Inc.,
      a Massachusetts corporation ("BFDS") which is duly registered as a
      transfer agent pursuant to Section 17A(c)(2) of the Securities Exchange
      Act of 1934, as  amended ("Section 17A(c)(2)"), (ii) a BFDS subsidiary
      duly registered as a transfer agent pursuant to Section 17A(c)(2) or (iii)
      a BFDS affiliate; provided, however, that the Bank shall be as fully
      responsible to the Fund for the acts and omissions of any subcontractor as
      it is for its own acts and omissions.

11.   Amendment
      ---------

      This Agreement may be amended or modified by a written agreement executed
      by both parties and authorized or approved by a resolution of the Board of
      Trustees of the Fund.

12.   Massachusetts Law to Apply
      --------------------------

      This Agreement shall be construed and the provisions thereof interpreted
      under and in accordance with the laws of the Commonwealth of
      Massachusetts.

13.   Force Majeure
      -------------

      In the event either party is unable to perform its obligations under the
      terms of this Agreement because of acts of God, strikes, equipment or
      transmission failure or damage reasonably beyond its control, or other
      causes reasonably beyond its control, such party shall not be liable for
      damages to the other for any damages resulting from such failure to
      perform or otherwise from such causes.

14.   Consequential Damages
      ---------------------

      Neither party to this Agreement shall be liable to the other party for
      consequential damages under any provision of this Agreement or for any
      consequential damages arising out of any act or failure to act hereunder.

15.   Merger of Agreement
      -------------------

      This Agreement constitutes the entire agreement between the parties hereto
      and supersedes any prior agreement with respect to the subject matter
      hereof whether oral or written.

16.   Limitations of Liability of the Trustees and Shareholders
      ---------------------------------------------------------

      A copy of the Declaration of Trust of the Trust is on file with the
      Secretary of the Commonwealth of Massachusetts, and notice is hereby given
      that this instrument is executed on behalf of the Trustees of the Trust as
      Trustees and not individually and that the obligations of this instrument
      are not binding upon any of the Trustees or Shareholders individually but
      are binding only upon the assets and property of the Fund.

                                       8
<PAGE>
 
17.   Counterparts
      ------------

      This Agreement may be executed by the parties hereto on any number of
      counterparts, and all of said counterparts taken together shall be deemed
      to constitute one and the same instrument.

18.   Reproduction of Documents
      -------------------------

      This Agreement and all schedules, exhibits, attachments and amendments
      hereto may be reproduced by any photographic, photostatic, microfilm,
      micro-card, miniature photographic or other similar process.  The parties
      hereto all/each agree that any such reproduction shall be admissible in
      evidence as the original itself in any judicial or administrative
      proceeding, whether or not the original is in existence and whether or not
      such reproduction was made by a party in the regular course of business,
      and that any enlargement, facsimile or further reproduction of such
      reproduction shall likewise be admissible in evidence.

                                       9
<PAGE>
 
IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed
in their names and on their behalf by and through their duly authorized
officers, as of the day and year first above written.



                               Loomis Sayles Funds on behalf of the
                               Loomis Sayles Managed Bond Fund Series
 

                               BY:  _____________________________
                                    Mark Holland, Treasurer
                                    Loomis Sayles Funds


ATTEST:


__________________________
 



                               STATE STREET BANK AND TRUST COMPANY


                               BY:  _____________________________
                                    Executive Vice President


ATTEST:


__________________________

                                      10
<PAGE>
 
                       STATE STREET BANK & TRUST COMPANY
                         FUND SERVICE RESPONSIBILITIES*



Service Performed                               Responsibility
- -----------------                               --------------
                                                Bank            Fund
                                                ----            ----

 1.  Receives orders for the purchase
     of Shares.                                                  X

 2.  Issue Shares and hold Shares in
     Shareholders accounts.                     X

 3.  Receive redemption requests.                                X

 4.  Effect transactions 1-3 above              N/A
     directly with broker-dealers.

 5.  Pay over monies to redeeming
     Shareholders.                              X

 6.  Effect transfers of Shares.                X

 7.  Prepare and transmit dividends
     and distributions.                         X

 8.  Issue Replacement Certificates.            N/A

 9.  Reporting of abandoned property.           X

10.  Maintain records of account.               X

11.  Maintain and keep a current and
     accurate control book for each
     issue of securities.                       N/A

12.  Mail proxies.                              X

13.  Mail Shareholder reports.                  X

14.  Mail prospectuses to current
     Shareholders.                                               X

15.  Withhold taxes on U.S. resident
     and non-resident alien accounts.           X

                                      11
<PAGE>
 
Service Performed                             Responsibility
- -----------------                             --------------
                                                Bank            Fund
                                                ----            ----
16.  Prepare and file U.S. Treasury
     Department forms.                          X

17.  Prepare and mail account and
     confirmation statements for
     Shareholders.                              X

18.  Provide Shareholder account
     information.                               X

19.  Blue sky reporting.                        N/A

*    Such services are more fully described in Section 1.2 (a), (b) and (c) of
     the Agreement.

                              Loomis Sayles Funds on behalf of the Loomis Sayles
                              Managed Bond Fund Series

                              BY: _______________________________
                                  Mark Holland, Treasurer
ATTEST:

___________________________

 



                              STATE STREET BANK AND TRUST COMPANY



                              BY: _______________________________
                                  Executive Vice President


ATTEST:


___________________________
 
                                      12

<PAGE>
 
CONSENT OF INDEPENDENT ACCOUNTANTS


To the Trustees of Loomis Sayles Funds:
    
     We consent to the incorporation by reference in Amendment No. 19 to the
Registration Statement of Loomis Sayles Funds consisting of Loomis Sayles Bond
Fund, Loomis Sayles Core Value Fund, Loomis Sayles Global Bond Fund, Loomis
Sayles Growth Fund, Loomis Sayles High Yield Fund, Loomis Sayles Intermediate
Maturity Bond Fund, Loomis Sayles International Equity Fund, Loomis Sayles
Investment Grade Bond Fund, Loomis Sayles Mid-Cap Growth Fund, Loomis Sayles 
Mid-Cap Value Fund, Loomis Sayles Municipal Bond Fund, Loomis Sayles Short-Term
Bond Fund, Loomis Sayles Small Cap Growth Fund, Loomis Sayles Small Cap Value
Fund, Loomis Sayles Strategic Value Fund, Loomis Sayles U.S. Government
Securities Fund, and Loomis Sayles Worldwide Fund, (collectively, the "Funds")
on Form N-1A (File No. 811-6241) under the Investment Company Act of 1940, as
amended, and Post-Effective Amendment No. 17 to the Registration Statement on
Form N-1A (File No. 33-39133) under the Securities Act of 1933, as amended, of
our reports dated November 18, 1998 on our audits of the financial statements
and financial highlights of the Funds, which reports are incorporated by
reference in the Amendment and Post-Effective Amendment to the Registration
Statement. We consent to the references to our Firm under the captions
"Financial Highlights" in the Prospectuses and "Independent Accountants" in the
Statement of Additional Information for the aforementioned Funds.     



Boston, Massachusetts                          PricewaterhouseCoopers LLP
November 30, 1998

<TABLE> <S> <C>

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<DIVIDEND-INCOME>                               31,051
<INTEREST-INCOME>                              201,895
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                (43,598)
<NET-INVESTMENT-INCOME>                        189,348
<REALIZED-GAINS-CURRENT>                        10,051
<APPREC-INCREASE-CURRENT>                    (818,235)
<NET-CHANGE-FROM-OPS>                        (618,836)
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                            0
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<PER-SHARE-NII>                                    .33
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<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                               8.79
<EXPENSE-RATIO>                                   1.00
<AVG-DEBT-OUTSTANDING>                               0
<AVG-DEBT-PER-SHARE>                                 0
        

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<PAID-IN-CAPITAL-COMMON>                     5,748,253
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<DIVIDEND-INCOME>                               31,051
<INTEREST-INCOME>                              201,895
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                (43,598)
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<REALIZED-GAINS-CURRENT>                        10,051
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<NET-CHANGE-FROM-OPS>                        (618,836)
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<GROSS-ADVISORY-FEES>                           32,580
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                156,064
<AVERAGE-NET-ASSETS>                            84,324
<PER-SHARE-NAV-BEGIN>                             9.86
<PER-SHARE-NII>                                    .30
<PER-SHARE-GAIN-APPREC>                         (1.40)
<PER-SHARE-DIVIDEND>                                 0
<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                               8.76
<EXPENSE-RATIO>                                   1.25
<AVG-DEBT-OUTSTANDING>                               0
<AVG-DEBT-PER-SHARE>                                 0
        

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<S>                             <C>
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<OVERDISTRIBUTION-GAINS>                             0
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<DIVIDEND-INCOME>                               54,959
<INTEREST-INCOME>                              893,606
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                (73,038)
<NET-INVESTMENT-INCOME>                        875,527
<REALIZED-GAINS-CURRENT>                       280,272
<APPREC-INCREASE-CURRENT>                  (3,203,138)
<NET-CHANGE-FROM-OPS>                      (2,047,339)
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                    (283,957)
<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                        403,057
<NUMBER-OF-SHARES-REDEEMED>                  (137,504)
<SHARES-REINVESTED>                             24,997
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<ACCUMULATED-NII-PRIOR>                              0
<ACCUMULATED-GAINS-PRIOR>                       80,356
<OVERDISTRIB-NII-PRIOR>                          (313)
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                           50,667
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                214,258
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<PER-SHARE-NAV-BEGIN>                            10.12
<PER-SHARE-NII>                                    .79
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<EXPENSE-RATIO>                                    .75
<AVG-DEBT-OUTSTANDING>                               0
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<PAID-IN-CAPITAL-COMMON>                    13,413,582
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<EXPENSES-NET>                                (73,038)
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
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   <NUMBER> 141
   <NAME> LOOMIS SAYLES INTERMEDIATE MATURITY BOND FUND, INSTITUTIONAL
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<S>                             <C>
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</TABLE>

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<PAGE>

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   <NAME> LOOMIS SAYLES INTERMEDIATE MATURITY BOND FUND, RETAIL
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<OTHER-INCOME>                                       0
<EXPENSES-NET>                                (36,043)
<NET-INVESTMENT-INCOME>                        426,463
<REALIZED-GAINS-CURRENT>                        67,050
<APPREC-INCREASE-CURRENT>                    (224,304)
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<EQUALIZATION>                                       0
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<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                         24,281 
<NUMBER-OF-SHARES-REDEEMED>                    (1,979)
<SHARES-REINVESTED>                              1,478
<NET-CHANGE-IN-ASSETS>                       2,536,364
<ACCUMULATED-NII-PRIOR>                              0
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<OVERDISTRIB-NII-PRIOR>                          (768)
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                           25,473
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                158,205
<AVERAGE-NET-ASSETS>                           544,021
<PER-SHARE-NAV-BEGIN>                            10.03
<PER-SHARE-NII>                                    .49
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<EXPENSE-RATIO>                                    .80
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</TABLE>

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<SERIES>
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   <NAME> LOOMIS SAYLES INVESTMENT GRADE BOND FUND, RETAIL
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<S>                             <C>
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   <NAME> LOOMIS SAYLES MID-CAP GROWTH FUND, INSTITUTIONAL
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</TABLE>

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<NAME> LOOMIS SAYLES & COMPANY, L.P.
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   <NAME> LOOMIS SAYLES MID-CAP GROWTH FUND, RETAIL
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</TABLE>

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<PAGE>

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<NAME> LOOMIS SAYLES & COMPANY, L.P.
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   <NAME> LOOMIS SAYLES MID-CAP VALUE FUND, INSTITUTIONAL
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</TABLE>

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<NAME> LOOMIS SAYLES & COMPANY, L.P.
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   <NAME> LOOMIS SAYLES MID-CAP VALUE FUND, RETAIL   
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</TABLE>

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   <NAME> LOOMIS SAYLES SMALL CAP GROWTH FUND, INSTITUTIONAL
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</TABLE>

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<NAME> LOOMIS SAYLES & COMPANY, L.P.
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   <NAME> LOOMIS SAYLES SMALL CAP GROWTH FUND, RETAIL
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</TABLE>

<TABLE> <S> <C>

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   <NAME> LOOMIS SAYLES STRATEGIC VALUE FUND, RETAIL 
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   <NAME> LOOMIS SAYLES INTERNATIONAL EQUITY FUND, INSTITUTIONAL
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</TABLE>

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<PAGE>

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<NAME> LOOMIS SAYLES & COMPANY, L.P.
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   <NAME> LOOMIS SAYLES INTERNATIONAL EQUITY FUND, RETAIL       
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</TABLE>

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<PAGE>

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<SERIES>
   <NUMBER> 051
   <NAME> LOOMIS SAYLES GLOBAL BOND FUND, INSTITUTIONAL
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</TABLE>

<TABLE> <S> <C>

<PAGE>

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<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
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   <NAME> LOOMIS SAYLES GLOBAL BOND FUND, RETAIL
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</TABLE>

<TABLE> <S> <C>

<PAGE>

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   <NAME> LOOMIS SAYLES GROWTH FUND, INSTITUTIONAL
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</TABLE>

<TABLE> <S> <C>

<PAGE>

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<NAME> LOOMIS SAYLES & COMPANY, L.P.
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   <NAME> LOOMIS SAYLES GROWTH FUND, RETAIL
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</TABLE>

<TABLE> <S> <C>

<PAGE>

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<NAME> LOOMIS SAYLES & COMPANY, L.P.
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   <NUMBER> 021
   <NAME> LOOMIS SAYLES CORE VALUE FUND, INSTITUTIONAL
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<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

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<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 022
   <NAME> LOOMIS SAYLES CORE VALUE FUND, RETAIL
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<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 033
   <NAME> LOOMIS SAYLES SMALL CAP VALUE FUND, ADMIN
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<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
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<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 031
   <NAME> LOOMIS SAYLES SMALL CAP VALUE FUND, INSTITUTIONAL
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<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 032
   <NAME> LOOMIS SAYLES SMALL CAP VALUE FUND, RETAIL
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<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 063
   <NAME> LOOMIS SAYLES BOND FUND, ADMIN
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<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 061
   <NAME> LOOMIS SAYLES BOND FUND, INSTITUTIONAL
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<S>                             <C>
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<PER-SHARE-NAV-BEGIN>                            12.83
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<EXPENSE-RATIO>                                    .75
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 062
   <NAME> LOOMIS SAYLES BOND FUND, RETAIL
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<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 070
   <NAME> LOOMIS SAYLES MUNICIPAL BOND FUND, INSTITUTIONAL
<MULTIPLIER> 1
       
<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 080
   <NAME> LOOMIS SAYLES U.S. GOVERNMENT FUND, INSTITUTIONAL
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<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 091
   <NAME> LOOMIS SAYLES SHORT-TERM BOND FUND, INSTITUTIONAL
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<S>                             <C>
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</TABLE>

<TABLE> <S> <C>

<PAGE>

<ARTICLE> 6
<CIK> 0000872649
<NAME> LOOMIS SAYLES & COMPANY, L.P.
<SERIES>
   <NUMBER> 092
   <NAME> LOOMIS SAYLES SHORT-TERM BOND FUND, RETAIL
<MULTIPLIER> 1
       
<S>                             <C>
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</TABLE>


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