WITTER DEAN CONVERTIBLE SECURITIES TRUST
485BPOS, 1997-07-17
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<PAGE>
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 17, 1997
 
                                                     REGISTRATION NOS.:  2-97963
                                                                        811-4310
 
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
                       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. 13                      /X/
                                     AND/OR
              REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY
                                  ACT OF 1940                                /X/
                                AMENDMENT NO. 14                             /X/
 
                               ------------------
 
                    DEAN WITTER CONVERTIBLE SECURITIES TRUST
                        (A MASSACHUSETTS BUSINESS TRUST)
               (EXACT NAME OF REGISTRANT AS SPECIFIED IN CHARTER)
 
                             TWO WORLD TRADE CENTER
                            NEW YORK, NEW YORK 10048
                    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICE)
 
       REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE: (212) 392-1600
 
                                BARRY FINK, ESQ.
                             TWO WORLD TRADE CENTER
                            NEW YORK, NEW YORK 10048
 
                    (NAME AND ADDRESS OF AGENT FOR SERVICE)
 
                                    Copy to:
 
                            DAVID M. BUTOWSKY, ESQ.
                             GORDON ALTMAN BUTOWSKY
                             WEITZEN SHALOV & WEIN
                              114 WEST 47TH STREET
                            NEW YORK, NEW YORK 10036
 
                              -------------------
 
                 APPROXIMATE DATE OF PROPOSED PUBLIC OFFERING:
 
 As soon as practicable after this Post-Effective Amendment becomes effective.
 
 IT IS PROPOSED THAT THIS FILING WILL BECOME EFFECTIVE (CHECK APPROPRIATE BOX)
        ___ immediately upon filing pursuant to paragraph (b)
        _X_ on (July 28, 1997) pursuant to paragraph (b)
        ___ 60 days after filing pursuant to paragraph (a)
        ___ on (date) pursuant to paragraph (a) of rule 485.
 
                              -------------------
 
    THE REGISTRANT HAS REGISTERED AN INDEFINITE NUMBER OF ITS SHARES UNDER THE
SECURITIES ACT OF 1933 PURSUANT TO SECTION (a)(1) OF RULE 24f-2 UNDER THE
INVESTMENT COMPANY ACT OF 1940. THE REGISTRANT FILED THE RULE 24f-2 NOTICE FOR
ITS FISCAL YEAR ENDED SEPTEMBER 30, 1996 WITH THE SECURITIES AND EXCHANGE
COMMISSION ON NOVEMBER 4, 1996.
 
           AMENDING THE PROSPECTUS AND UPDATING FINANCIAL STATEMENTS
 
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<PAGE>
                    DEAN WITTER CONVERTIBLE SECURITIES TRUST
 
                             CROSS-REFERENCE SHEET
 
                                   FORM N-1A
 
<TABLE>
<CAPTION>
ITEM                                                                           CAPTION
- ----------------------------------------------  ---------------------------------------------------------------------
<S>                                             <C>
PART A                                                                       PROSPECTUS
 1.  .........................................  Cover Page
 2.  .........................................  Prospectus Summary; Summary of Fund Expenses
 3.  .........................................  Financial Highlights; Performance Information
 4.  .........................................  Investment Objective and Policies; The Fund and Its Management, Cover
                                                 Page; Investment Restrictions; Prospectus Summary; Financial
                                                 Highlights; Appendix
 5.  .........................................  The Fund and Its Management; Back Cover; Investment Objectives and
                                                 Policies
 6.  .........................................  Dividends, Distributions and Taxes; Additional Information
 7.  .........................................  Purchase of Fund Shares; Shareholder Services; Prospectus Summary
 8.  .........................................  Purchase of Fund Shares; Redemptions and Repurchases; Shareholder
                                                 Services
 9.  .........................................  Not applicable
 
PART B                                                           STATEMENT OF ADDITIONAL INFORMATION
10.  .........................................  Cover Page
11.  .........................................  Table of Contents
12.  .........................................  The Fund and Its Management
13.  .........................................  Investment Practices and Policies; Investment Restrictions; Portfolio
                                                 Transactions and Brokerage
14.  .........................................  The Fund and Its Management; Trustees and Officers
15.  .........................................  The Fund and Its Management; Trustees and Officers
16.  .........................................  The Fund and Its Management; The Distributor; Shareholder Services;
                                                 Custodian and Transfer Agent; Independent Accountants
17.  .........................................  Portfolio Transactions and Brokerage
18.  .........................................  Description of Shares of the Fund
19.  .........................................  The Distributor; Purchase of Fund Shares; Redemptions and
                                                 Repurchases; Financial Statements; Shareholder Services
20.  .........................................  Dividends, Distributions and Taxes; Financial Statements
21.  .........................................  The Distributor
22.  .........................................  Performance Information
23.  .........................................  Experts; Financial Statements
</TABLE>
 
PART C
 
    Information required to be included in Part C is set forth under the
appropriate item, so numbered, in Part C of this Registration Statement.
<PAGE>
   
              PROSPECTUS
              JULY 28, 1997
    
 
   
              Dean Witter Convertible Securities Trust (the "Fund") is an
open-end diversified management investment company whose investment objective is
to seek a high level of total return on its assets through a combination of
current income and capital appreciation. It seeks to achieve its investment
objective by investing principally in "convertible securities," that is, bonds,
notes, debentures, preferred stocks and other securities which are convertible
into common stock. INVESTORS SHOULD CAREFULLY CONSIDER THE RELATIVE RISKS OF
INVESTING IN HIGH YIELD SECURITIES, WHICH ARE COMMONLY KNOWN AS JUNK BONDS.
BONDS OF THIS TYPE ARE CONSIDERED TO BE SPECULATIVE WITH REGARD TO THE PAYMENT
OF INTEREST AND RETURN OF PRINCIPAL. INVESTORS SHOULD ALSO BE COGNIZANT OF THE
FACT THAT SUCH SECURITIES ARE NOT GENERALLY MEANT FOR SHORT-TERM INVESTING AND
SHOULD ASSESS THE RISKS ASSOCIATED WITH AN INVESTMENT IN THE FUND. (See
"Investment Objective and Policies.")
    
 
   
               The Fund offers four classes of shares (each, a "Class"), each
with a different combination of sales charges, ongoing fees and other features.
The different distribution arrangements permit an investor to choose the method
of purchasing shares that the investor believes is most beneficial given the
amount of the purchase, the length of time the investor expects to hold the
shares and other relevant circumstances. Shares of the Fund held prior to July
28, 1997 have been designated Class B shares. (See "Purchase of Fund Shares--
Alternative Purchase Arrangements.")
    
 
   
               This Prospectus sets forth concisely the information you should
know before investing in the Fund. It should be read and retained for future
reference. Additional information about the Fund is contained in the Statement
of Additional Information, dated July 28, 1997, which has been filed with the
Securities and Exchange Commission, and which is available at no charge upon
request of the Fund at the address or telephone numbers listed on this page. The
Statement of Additional Information is incorporated herein by reference.
    
 
     DEAN WITTER DISTRIBUTORS INC.
     DISTRIBUTOR
 
      TABLE OF CONTENTS
 
   
Prospectus Summary/2
Summary of Fund Expenses/4
Financial Highlights/6
The Fund and its Management/7
Investment Objective and Policies/7
  Risk Considerations/8
Investment Restrictions/14
Purchase of Fund Shares/15
Shareholder Services/26
Redemptions and Repurchases/29
Dividends, Distributions and Taxes/30
Performance Information/31
Additional Information/32
Appendix--Ratings of Investments/34
    
 
SHARES OF THE FUND ARE NOT DEPOSITS OR OBLIGATIONS OF, OR GUARANTEED OR ENDORSED
BY, ANY BANK, AND THE SHARES ARE NOT FEDERALLY INSURED BY THE FEDERAL DEPOSIT
INSURANCE CORPORATION, THE FEDERAL RESERVE BOARD, OR ANY OTHER AGENCY.
 
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.
 
    Dean Witter
    Convertible Securities Trust
    Two World Trade Center
    New York, New York 10048
    (212) 392-2550 or
    (800) 869-NEWS (toll-free)
<PAGE>
PROSPECTUS SUMMARY
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<TABLE>
<S>             <C>
The             The Fund is organized as a Trust, commonly known as a Massachusetts business
Fund            trust, and is an open-end diversified management investment company investing
                principally in corporate securities that can be converted into common stock.
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Shares Offered  Shares of beneficial interest with $0.01 par value (see page 32). The Fund offers
                four Classes of shares, each with a different combination of sales charges,
                ongoing fees and other features (see page 15).
- --------------------------------------------------------------------------------------------------
Minimum         The minimum initial investment for each Class is $1,000 ($100 if the account is
Purchase        opened through EasyInvest-SM-). Class D shares are only available to persons
                investing $5 million or more and to certain other limited categories of investors.
                For the purpose of meeting the minimum $5 million investment for Class D shares,
                and subject to the $1,000 minimum initial investment for each Class of the Fund,
                an investor's existing holdings of Class A shares and shares of funds for which
                Dean Witter InterCapital Inc. serves as investment manager ("Dean Witter Funds")
                that are sold with a front-end sales charge, and concurrent investments in Class D
                shares of the Fund and other Dean Witter Funds that are multiple class funds, will
                be aggregated. The minimum subsequent investment is $100 (see page 15).
- --------------------------------------------------------------------------------------------------
Investment      The investment objective of the Fund is to seek a high level of total return on
Objective       its assets through a combination of current income and capital appreciation. It
                seeks to achieve this objective by investing principally in "convertible
                securities," that is bonds, notes, debentures, preferred stocks and other
                securities which are convertible into common stock.
- --------------------------------------------------------------------------------------------------
Investment      Dean Witter InterCapital Inc. ("InterCapital"), the Investment Manager of the Fund
Manager         and its wholly- owned subsidiary, Dean Witter Services Company Inc., serve in
                various investment management, advisory, management and administrative capacities
                to 100 investment companies and other portfolios with assets of approximately
                $96.6 billion at June 30, 1997 (see page 7).
- --------------------------------------------------------------------------------------------------
Management      The Investment Manager receives a monthly fee at the annual rate of 0.60 of 1% of
Fee             the Fund's net assets not exceeding $750 million, scaled down at various asset
                levels to 0.425 of 1% of the Fund's daily net assets exceeding $3 billion,
                determined as of the close of each business day. (see page 7).
- --------------------------------------------------------------------------------------------------
Distributor     Dean Witter Distributors Inc. (the "Distributor"). The Fund has adopted a
and             distribution plan pursuant to Rule 12b-1 under the Investment Company Act (the
Distribution    "12b-1 Plan") with respect to the distribution fees paid by the Class A, Class B
Fee             and Class C shares of the Fund to the Distributor. The entire 12b-1 fee payable by
                Class A and a portion of the 12b-1 fee payable by each of Class B and Class C
                equal to 0.25% of the average daily net assets of the Class are currently each
                characterized as a service fee within the meaning of the National Association of
                Securities Dealers, Inc. guidelines. The remaining portion of the 12b-1 fee, if
                any, is characterized as an asset-based sales charge (see pages 15 and 24).
- --------------------------------------------------------------------------------------------------
Alternative     Four classes of shares are offered:
Purchase
Arrangements    - Class A shares are offered with a front-end sales charge, starting at 5.25% and
                reduced for larger purchases. Investments of $1 million or more (and investments
                by certain other limited categories of investors) are not subject to any sales
                charge at the time of purchase but a contingent deferred sales charge ("CDSC") of
                1.0% may be imposed on redemptions within one year of purchase. The Fund is
                authorized to reimburse the Distributor for specific expenses incurred in
                promoting the distribution of the Fund's Class A shares and servicing shareholder
                accounts pursuant to the Fund's 12b-1 Plan. Reimbursement may in no event exceed
                an amount equal to payments at an annual rate of 0.25% of average daily net assets
                of the Class (see pages 15, 18 and 24).
</TABLE>
    
 
                                       2
<PAGE>
- --------------------------------------------------------------------------------
   
<TABLE>
<S>             <C>
                - Class B shares are offered without a front-end sales charge, but will in most
                cases be subject to a CDSC (scaled down from 5.0% to 1.0%) if redeemed within six
                years after purchase. The CDSC will be imposed on any redemption of shares if
                after such redemption the aggregate current value of a Class B account with the
                Fund falls below the aggregate amount of the investor's purchase payments made
                during the six years preceding the redemption. A different CDSC schedule applies
                to investments by certain qualified plans. Class B shares are also subject to a
                12b-1 fee assessed at the annual rate of 1.0% of the lesser of: (a) the average
                daily net sales of the Fund's Class B shares or (b) the average daily net assets
                of Class B. All shares of the Fund held prior to July 28, 1997 have been
                designated Class B shares. Shares held before May 1, 1997 will convert to Class A
                shares in May, 2007. In all other instances, Class B shares convert to Class A
                shares approximately ten years after the date of the original purchase (see pages
                15, 21 and 24).
 
                - Class C shares are offered without a front-end sales charge, but will in most
                cases be subject to a CDSC of 1.0% if redeemed within one year after purchase. The
                Fund is authorized to reimburse the Distributor for specific expenses incurred in
                promoting the distribution of the Fund's Class C shares and servicing shareholder
                accounts pursuant to the Fund's 12b-1 Plan. Reimbursement may in no event exceed
                an amount equal to payments at an annual rate of 1.0% of average daily net assets
                of the Class (see pages 15, 23 and 24).
 
                - Class D shares are offered only to investors meeting an initial investment
                minimum of $5 million and to certain other limited categories of investors. Class
                D shares are offered without a front-end sales charge or CDSC and are not subject
                to any 12b-1 fee (see pages 15, 23 and 24).
- --------------------------------------------------------------------------------------------------
Dividends       Income dividends are paid quarterly; capital gains, if any, are paid at least once
and             per year. The Fund may, however, determine to retain all or part of any net
Capital Gains   long-term capital gains in any year for reinvestment. Dividends and capital gains
Distributions   distributions paid on shares of a Class are automatically reinvested in additional
                shares of the same Class at net asset value unless the shareholder elects to
                receive cash. Shares acquired by dividend and distribution reinvestment will not
                be subject to any sales charge or CDSC (see pages 26 and 30).
- --------------------------------------------------------------------------------------------------
Redemption      Shares are redeemable by the shareholder at net asset value less any applicable
                CDSC on Class A, Class B or Class C shares. An account may be involuntarily
                redeemed if the total value of the account is less than $100 or, if the account
                was opened through EasyInvest-SM-, if after twelve months the shareholder has
                invested less than $1,000 in the account (see page 29).
- --------------------------------------------------------------------------------------------------
Risks           The net asset value of the Fund's shares will fluctuate with changes in the market
                value of its portfolio securities. Emphasis on convertible securities will result
                in price fluctuations of the Fund's portfolio securities with varying interest
                rates and with changes in the prices of the common stocks associated with their
                conversion rights. In addition, the investor is directed to the discussions of
                corporate fixed-income securities (certain of which may be lower rated securities
                commonly known as "junk bonds" or securities which are unrated by recognized
                rating agencies), "enhanced" and "synthetic" convertible securities, when-issued
                and delayed delivery securities and forward commitments, when, as and if issued
                securities, options, futures contracts, foreign securities, repurchase agreements,
                and options on futures (see page 8).
- --------------------------------------------------------------------------------------------------
</TABLE>
    
 
<TABLE>
<S>              <C>
 THE ABOVE IS QUALIFIED IN ITS ENTIRETY BY THE DETAILED INFORMATION APPEARING ELSEWHERE IN THIS PROSPECTUS
                              AND IN THE STATEMENT OF ADDITIONAL INFORMATION.
</TABLE>
 
                                       3
<PAGE>
   
SUMMARY OF FUND EXPENSES
    
- --------------------------------------------------------------------------------
 
   
The following table illustrates all expenses and fees that a shareholder of the
Fund will incur. The expenses and fees set forth in the table are based on the
expenses and fees for the fiscal year ended September 30, 1996.
    
 
   
<TABLE>
<CAPTION>
                                                                       CLASS A      CLASS B      CLASS C      CLASS D
                                                                     -----------  -----------  -----------  -----------
<S>                                                                  <C>          <C>          <C>          <C>
SHAREHOLDER TRANSACTION EXPENSES
- -------------------------------------------------------------------
Maximum Sales Charge Imposed on Purchases (as a percentage of
 offering price)...................................................        5.25%(1)       None       None         None
Sales Charge Imposed on Dividend Reinvestments.....................        None         None         None         None
Maximum Contingent Deferred Sales Charge (as a percentage of
 original purchase price or redemption proceeds)...................        None(2)       5.00%(3)       1.00%(4)       None
Redemption Fees....................................................        None         None         None         None
Exchange Fee.......................................................        None         None         None         None
 
ANNUAL FUND OPERATING EXPENSES (AS A PERCENTAGE OF AVERAGE NET
 ASSETS)
- -------------------------------------------------------------------
Management Fees....................................................        0.60%        0.60%        0.60%        0.60%
12b-1 Fees (5) (6).................................................        0.25%        1.00%        1.00%        None
Other Expenses.....................................................        0.29%        0.29%        0.29%        0.29%
Total Fund Operating Expenses (7)..................................        1.14%        1.89%        1.89%        0.89%
</TABLE>
    
 
- ------------
   
(1) REDUCED FOR PURCHASES OF $25,000 AND OVER (SEE "PURCHASE OF FUND
    SHARES--INITIAL SALES CHARGE ALTERNATIVE--CLASS A SHARES").
    
 
   
(2) INVESTMENTS THAT ARE NOT SUBJECT TO ANY SALES CHARGE AT THE TIME OF PURCHASE
    ARE SUBJECT TO A CDSC OF 1.00% THAT WILL BE IMPOSED ON REDEMPTIONS MADE
    WITHIN ONE YEAR AFTER PURCHASE, EXCEPT FOR CERTAIN SPECIFIC CIRCUMSTANCES
    (SEE "PURCHASE OF FUND SHARES--INITIAL SALES CHARGE ALTERNATIVE--CLASS A
    SHARES").
    
 
   
(3) THE CDSC IS SCALED DOWN TO 1.00% DURING THE SIXTH YEAR, REACHING ZERO
    THEREAFTER.
    
 
   
(4) ONLY APPLICABLE TO REDEMPTIONS MADE WITHIN ONE YEAR AFTER PURCHASE (SEE
    "PURCHASE OF FUND SHARES-- LEVEL LOAD ALTERNATIVE--CLASS C SHARES").
    
 
   
(5) THE 12B-1 FEE IS ACCRUED DAILY AND PAYABLE MONTHLY. THE ENTIRE 12B-1 FEE
    PAYABLE BY CLASS A AND A PORTION OF THE 12B-1 FEE PAYABLE BY EACH OF CLASS B
    AND CLASS C EQUAL TO 0.25% OF THE AVERAGE DAILY NET ASSETS OF THE CLASS ARE
    CURRENTLY EACH CHARACTERIZED AS A SERVICE FEE WITHIN THE MEANING OF NATIONAL
    ASSOCIATION OF SECURITIES DEALERS, INC. ("NASD") GUIDELINES AND ARE PAYMENTS
    MADE FOR PERSONAL SERVICE AND/OR MAINTENANCE OF SHAREHOLDER ACCOUNTS. THE
    REMAINDER OF THE 12B-1 FEE, IF ANY, IS AN ASSET-BASED SALES CHARGE, AND IS A
    DISTRIBUTION FEE PAID TO THE DISTRIBUTOR TO COMPENSATE IT FOR THE SERVICES
    PROVIDED AND THE EXPENSES BORNE BY THE DISTRIBUTOR AND OTHERS IN THE
    DISTRIBUTION OF THE FUND'S SHARES (SEE "PURCHASE OF FUND SHARES--PLAN OF
    DISTRIBUTION").
    
 
   
(6) UPON CONVERSION OF CLASS B SHARES TO CLASS A SHARES, SUCH SHARES WILL BE
    SUBJECT TO THE LOWER 12B-1 FEE APPLICABLE TO CLASS A SHARES. NO SALES CHARGE
    IS IMPOSED AT THE TIME OF CONVERSION OF CLASS B SHARES TO CLASS A SHARES.
    CLASS C SHARES DO NOT HAVE A CONVERSION FEATURE AND, THEREFORE, ARE SUBJECT
    TO AN ONGOING 1.00% DISTRIBUTION FEE (SEE "PURCHASE OF FUND
    SHARES--ALTERNATIVE PURCHASE ARRANGEMENTS").
    
 
   
(7) THERE WERE NO OUTSTANDING SHARES OF CLASS A, CLASS C OR CLASS D PRIOR TO THE
    DATE OF THIS PROSPECTUS. ACCORDINGLY, "TOTAL FUND OPERATING EXPENSES," AS
    SHOWN ABOVE WITH RESPECT TO THOSE CLASSES, ARE BASED UPON THE SUM OF 12B-1
    FEES, MANAGEMENT FEES AND ESTIMATED "OTHER EXPENSES."
    
 
                                       4
<PAGE>
- --------------------------------------------------------------------------------
   
<TABLE>
<CAPTION>
EXAMPLES                                                                              1 YEAR       3 YEARS      5 YEARS
- ----------------------------------------------------------------------------------  -----------  -----------  -----------
<S>                                                                                 <C>          <C>          <C>
You would pay the following expenses on a $1,000 investment assuming (1) a 5%
annual return and (2) redemption at the end of each time period:
    Class A.......................................................................   $      64    $      87    $     112
    Class B.......................................................................   $      69    $      89    $     122
    Class C.......................................................................   $      29    $      59    $     102
    Class D.......................................................................   $       9    $      28    $      49
 
You would pay the following expenses on the same $1,000 investment assuming no
redemption at the end of the period:
    Class A.......................................................................   $      64    $      87    $     112
    Class B.......................................................................   $      19    $      59    $     102
    Class C.......................................................................   $      19    $      59    $     102
    Class D.......................................................................   $       9    $      28    $      49
 
<CAPTION>
EXAMPLES                                                                             10 YEARS
- ----------------------------------------------------------------------------------  -----------
<S>                                                                                 <C>
You would pay the following expenses on a $1,000 investment assuming (1) a 5%
annual return and (2) redemption at the end of each time period:
    Class A.......................................................................   $     184
    Class B.......................................................................   $     221
    Class C.......................................................................   $     221
    Class D.......................................................................   $     110
You would pay the following expenses on the same $1,000 investment assuming no
redemption at the end of the period:
    Class A.......................................................................   $     184
    Class B.......................................................................   $     221
    Class C.......................................................................   $     221
    Class D.......................................................................   $     110
</TABLE>
    
 
   
    THE ABOVE EXAMPLES SHOULD NOT BE CONSIDERED A REPRESENTATION OF PAST OR
FUTURE EXPENSES OR PERFORMANCE. ACTUAL EXPENSES OF EACH CLASS MAY BE GREATER OR
LESS THAN THOSE SHOWN.
    
 
   
    The purpose of this table is to assist the investor in understanding the
various costs and expenses that an investor in the Fund will bear directly or
indirectly. For a more complete description of these costs and expenses, see
"The Fund and its Management," "Purchase of Fund Shares--Plan of Distribution"
and "Redemptions and Repurchases."
    
 
   
    Long-term shareholders of Class B and Class C may pay more in sales charges,
including distribution fees, than the economic equivalent of the maximum
front-end sales charges permitted by the NASD.
    
 
                                       5
<PAGE>
FINANCIAL HIGHLIGHTS
- --------------------------------------------------------------------------------
 
   
    The following ratios and per share data for a share of beneficial interest
outstanding throughout each of the periods through September 30, 1996 have been
audited by Price Waterhouse LLP, independent accountants. The information for
the six-month period ended March 31, 1997 is unaudited. The financial highlights
should be read in conjunction with the financial statements, the notes thereto
and the unqualified report of independent accountants, which are contained in
the Statement of Additional Information. Further information about the
performance of the Fund is contained in the Fund's Annual Report to
Shareholders, which may be obtained without charge upon request to the Fund. All
shares of the Fund held prior to July 28, 1997 have been designated Class B
shares.
    
 
   
<TABLE>
<CAPTION>
                                                                 FOR THE YEAR ENDED SEPTEMBER 30
                                 -----------------------------------------------------------------------------------------------
                                   1996      1995     1994     1993     1992     1991     1990       1989      1988       1987
                      FOR THE    --------   -------  -------  -------  -------  -------  -------    -------   -------    -------
                        SIX
                       MONTHS
                       ENDED
                       MARCH
                      31, 1997
                      --------
                      (UNAUDITED)
<S>                   <C>        <C>        <C>      <C>      <C>      <C>      <C>      <C>        <C>       <C>        <C>
PER SHARE OPERATING
 PERFORMANCE:
  Net asset value,
   beginning of
   period...........    12.72    $ 11.67    $ 10.75  $ 10.62  $  8.92  $  8.67  $  7.65  $ 9.68     $  8.63   $12.42     $ 11.22
                      --------   --------   -------  -------  -------  -------  -------  -------    -------   -------    -------
  Net investment
   income...........     0.26       0.55       0.60     0.42     0.37     0.34     0.37    0.46        0.48     0.38        0.48
  Net realized and
   unrealized gain
   (loss)...........     0.27       1.12       0.82     0.11     1.67     0.15     1.05   (2.06)       1.20    (2.87)       1.59
                      --------   --------   -------  -------  -------  -------  -------  -------    -------   -------    -------
  Total from
   investment
   operations.......     0.53       1.67       1.42     0.53     2.04     0.49     1.42   (1.60)       1.68    (2.49)       2.07
                      --------   --------   -------  -------  -------  -------  -------  -------    -------   -------    -------
  Less dividends and
   distributions
   from:
    Net investment
     income.........    (0.29)     (0.62)     (0.50)   (0.40)   (0.34)   (0.24)   (0.40)  (0.43)      (0.63)   (0.23)      (0.46)
    Net realized
     gain...........      -0-        -0-        -0-      -0-      -0-      -0-      -0-     -0-         -0-    (1.07)      (0.41)
                      --------   --------   -------  -------  -------  -------  -------  -------    -------   -------    -------
  Total dividends
   and
   distributions....    (0.29)     (0.62)     (0.50)   (0.40)   (0.34)   (0.24)   (0.40)  (0.43)      (0.63)   (1.30)      (0.87)
                      --------   --------   -------  -------  -------  -------  -------  -------    -------   -------    -------
  Net asset value,
   end of period....  $ 12.96    $ 12.72    $ 11.67  $ 10.75  $ 10.62  $  8.92  $  8.67  $ 7.65     $  9.68   $ 8.63     $ 12.42
                      --------   --------   -------  -------  -------  -------  -------  -------    -------   -------    -------
                      --------   --------   -------  -------  -------  -------  -------  -------    -------   -------    -------
TOTAL INVESTMENT
 RETURN+............    4.17%(1)  14.70%     13.68%    5.02%   23.22%    5.69%   18.93%  (16.93)%    20.20%   (19.79)%    19.21%
RATIOS TO AVERAGE
 NET ASSETS:
  Expenses..........    1.84%(2)   1.89%      1.96%    1.93%    1.93%    1.92%    1.92%   1.88%       1.76%    1.79%       1.62%
  Net investment
   income...........    4.27%(2)   4.78%      5.24%    3.68%    3.44%    3.43%    4.34%   4.96%       4.93%    3.87%       3.85%
SUPPLEMENTAL DATA:
  Net assets, end of
   period, in
   millions.........     $256       $234       $185     $190     $208     $218     $297    $413        $822   $1,073      $2,029
  Portfolio turnover
   rate.............      82%(1)    171%       138%     184%     221%     145%     133%     92%        167%     472%        572%
  Average commission
   rate paid........  $0.0566     $0.0581        --       --       --       --       --      --          --       --          --
</TABLE>
    
 
- ------------
+ DOES NOT REFLECT THE DEDUCTION OF SALES CHARGE. CALCULATED BASED ON THE NET
  ASSET VALUE AS OF THE LAST BUSINESS DAY OF THE PERIOD.
   
(1) NOT ANNUALIZED.
    
   
(2) ANNUALIZED.
    
 
                                       6
<PAGE>
THE FUND AND ITS MANAGEMENT
- --------------------------------------------------------------------------------
 
    Dean Witter Convertible Securities Trust (the "Fund") is an open-end
diversified management investment company. The Fund is a trust of the type
commonly known as a "Massachusetts business trust" and was organized under the
laws of the Commonwealth of Massachusetts on May 21, 1985.
 
   
    Dean Witter InterCapital Inc. ("InterCapital" or the "Investment Manager"),
whose address is Two World Trade Center, New York, New York 10048, is the Fund's
Investment Manager. The Investment Manager, which was incorporated in July,
1992, is a wholly-owned subsidiary of Morgan Stanley, Dean Witter, Discover &
Co., a preeminent global financial services firm that maintains leading market
positions in each of its three primary businesses -- securities, asset
management and credit services.
    
 
   
    InterCapital and its wholly-owned subsidiary, Dean Witter Services Company
Inc., serve in various investment management, advisory, management and
administrative capacities to 100 investment companies, 30 of which are listed on
the New York Stock Exchange, with combined total net assets of approximately
$93.1 billion as of June 30, 1997. The Investment Manager also manages and
advises managers of portfolios of pension plans, other institutions and
individuals which aggregated approximately $3.5 billion at such date.
    
 
    The Fund has retained the Investment Manager to provide administrative
services, manage its business affairs and manage the investment of the Fund's
assets, including the placing of orders for the purchase and sale of portfolio
securities. InterCapital has retained Dean Witter Services Company Inc. to
perform the aforementioned administrative services for the Fund.
 
    The Fund's Trustees review the various services provided by or under the
direction of the Investment Manager to ensure that the Fund's general investment
policies and programs are being properly carried out and that administrative
services are being provided to the Fund in a satisfactory manner.
 
    As full compensation for the services and facilities furnished to the Fund
and for expenses of the Fund assumed by the Investment Manager, the Fund pays
the Investment Manager monthly compensation calculated daily by applying the
following annual rates to the Fund's net assets determined as of the close of
each business day: 0.60% of the portion of the daily net assets not exceeding
$750 million, scaled down at various asset levels to 0.425% of the portion of
the daily net assets exceeding $3 billion. For the fiscal year ended September
30, 1996, the Fund accrued total compensation to the Investment Manager
amounting to 0.60% of the Fund's average daily net assets and the Fund's total
expenses amounted to 1.89% of the Fund's average daily net assets.
 
INVESTMENT OBJECTIVE AND POLICIES
- --------------------------------------------------------------------------------
 
    The investment objective of the Fund is to seek a high level of total return
on its assets through a combination of current income and capital appreciation.
There is no assurance that this objective will be achieved. It is a fundamental
policy of the Fund and cannot be changed without shareholder approval. The
following policies may be changed by the Trustees of the Fund without
shareholder approval.
 
    (1) The Fund will normally invest at least 65% of its total assets (taken at
current value) in "convertible securities," i.e., securities (bonds, debentures,
corporate notes, preferred stocks and other securities) which are convertible
into common stock. Securities received upon conversion may be retained in the
Fund's portfolio to permit orderly disposition or to establish long-term holding
periods for federal income tax purposes. The Fund is
 
                                       7
<PAGE>
not required to sell these securities for the purpose of assuring that 65% of
its assets are invested in convertible securities.
 
    (2) The Fund may invest up to 35% of its total assets (taken at current
value and subject to any restrictions appearing elsewhere in this Prospectus) in
any combination and quantity of the following securities: (a) common stock; (b)
nonconvertible preferred stock; (c) nonconvertible corporate debt securities;
(d) options on debt and equity securities; (e) financial futures contracts and
related options thereon; and (f) money market instruments.
 
    (3) Notwithstanding paragraphs (1) and (2) above, when market conditions
dictate a "defensive" investment strategy, the Fund may invest without limit in
money market instruments, including commercial paper, certificates of deposit,
bankers' acceptances and other obligations of domestic banks or domestic
branches of foreign banks, or foreign branches of domestic banks, in each case
having total assets of at least $500 million, and obligations issued or
guaranteed by the United States Government, or foreign governments or their
respective instrumentalities or agencies.
 
    The Fund may invest in fixed-income securities rated Baa or lower by Moody's
Investors Service, Inc. ("Moody's"), or BBB or lower by Standard & Poor's
Corporation ("S&P"). Fixed-income securities rated Baa by Moody's or BBB by S&P
have speculative characteristics greater than those of more highly rated bonds,
while fixed-income securities rated Ba or BB or lower by Moody's and S&P,
respectively, are considered to be speculative investments. Furthermore, the
Fund does not have any minimum quality rating standard for its investments. As
such, the Fund may invest in securities rated as low as Caa, Ca or C by Moody's
or CCC, CC, C or C1 by S&P. Fixed-income securities rated Caa or Ca by Moody's
may already be in default on payment of interest or principal, while bonds rated
C by Moody's, their lowest bond rating, can be regarded as having extremely poor
prospects of ever attaining any real investment standing. Bonds rated C1 by S&P,
their lowest bond rating, are no longer making interest payments.
 
    Non-rated securities are also considered for investment by the Fund when the
Investment Manager believes that the financial condition of the issuers of such
securities, or the protection afforded by the terms of the securities
themselves, makes them appropriate investments for the Fund.
 
    A general description of Moody's and S&P's ratings is set forth in the
Appendix at the end of this Prospectus.
 
RISK CONSIDERATIONS
 
    CONVERTIBLE SECURITIES.  The Fund will seek to meet its investment objective
by investing primarily in convertible securities in accordance with the
above-stated policies. Investments in these securities can provide a high level
of total return by virtue of their affording current income through interest and
dividend payments and because of the opportunity they provide for capital
appreciation by virtue of their convertibility into common stock. The Fund may
invest in investment grade convertible securities which are rated within the
four highest categories by recognized rating agencies; i.e., S & P and Moody's,
as well as in such securities which are lower rated or which are not rated by
such agencies. See the Statement of Additional Information for a discussion of
S&P and Moody's ratings.
 
    Convertible securities rank senior to common stocks in a corporation's
capital structure and, therefore, entail less risk than the corporation's common
stock. The value of a convertible security is a function of its "investment
value" (its value as if it did not have a conversion privilege), and its
"conversion value" (the security's worth if it were to be exchanged for the
underlying security, at market value, pursuant to its conversion privilege).
 
    To the extent that a convertible security's investment value is greater than
its conversion value, its price will be primarily a reflection of such
investment value and its price will be likely to increase when interest rates
fall and decrease when interest rates
 
                                       8
<PAGE>
rise, as with a fixed-income security (the credit standing of the issuer and
other factors may also have an effect on the convertible security's value). If
the conversion value exceeds the investment value, the price of the convertible
security will rise above its investment value and, in addition, will sell at
some premium over its conversion value. (This premium represents the price
investors are willing to pay for the privilege of purchasing a fixed-income
security with a possibility of capital appreciation due to the conversion
privilege.) At such times the price of the convertible security will tend to
fluctuate directly with the price of the underlying equity security. Convertible
securities may be purchased by the Fund at varying price levels above their
investment values and/or their conversion values in keeping with the Fund's
objective.
 
    The Fund may invest up to 25% of its total assets in "enhanced" convertible
securities. Enhanced convertible securities offer holders the opportunity to
obtain higher current income than would be available from a traditional equity
security issued by the same company, in return for reduced participation or a
cap on appreciation in the underlying common stock of the issuer which the
holder can realize. In addition, in many cases, enhanced convertible securities
are convertible into the underlying common stock of the issuer automatically at
maturity, unlike traditional convertible securities which are convertible only
at the option of the security holder. Enhanced convertible securities may be
more volatile than traditional convertible securities due to the mandatory
conversion feature.
 
    The Fund also may invest up to 10% in "synthetic" convertible securities.
Unlike traditional convertible securities whose conversion values are based on
the common stock of the issuer of the convertible security, "synthetic"
convertible securities are preferred stocks or debt obligations of an issuer
which are combined with an equity component whose conversion value is based on
the value of the common stock of a different issuer or a particular benchmark
(which may include a foreign issuer or basket of foreign stocks, or a company
whose stock is not yet publicly traded). In many cases, "synthetic" convertible
securities are not convertible prior to maturity, at which time the value of the
security is paid in cash by the issuer.
 
    "Synthetic" convertible securities may be less liquid than traditional
convertible securities and their price changes may be more volatile. Reduced
liquidity may have an adverse impact on the Fund's ability to sell particular
synthetic securities promptly at favorable prices and may also make it more
difficult for the Fund to obtain market quotations based on actual trades, for
purposes of valuing the Fund's portfolio securities.
 
    The Fund may invest without limitation in "exchangeable" convertible bonds
and convertible preferred stock which are issued by one company, but convertible
into the common stock of a different publicly traded company. These securities
generally have liquidity trading and risk characteristics similar to traditional
convertible securities noted above.
 
    ZERO COUPON SECURITIES.  A portion of the securities purchased by the Fund
may be zero coupon securities. Such securities are purchased at a discount from
their face amount, giving the purchaser the right to receive their full value at
maturity. The interest earned on such securities is, implicitly, automatically
compounded and paid out at maturity. While such compounding at a constant rate
eliminates the risk of receiving lower yields upon reinvestment of interest if
prevailing interest rates decline, the owner of a zero coupon security will be
unable to participate in higher yields upon reinvestment of interest received on
interest-paying securities if prevailing interest rates rise.
 
    A zero coupon security pays no interest to its holder during its life.
Therefore, to the extent the Fund invests in zero coupon securities, it will not
receive current cash available for distribution to shareholders. In addition,
zero coupon securities are subject to substantially greater price fluctuations
during periods of changing prevailing interest rates than are comparable
securities which pay interest on a current basis. Current federal tax law
requires that a holder (such as the Fund) of a zero coupon security accrue a
portion of the discount at
 
                                       9
<PAGE>
which the security was purchased as income each year even though the Fund
receives no interest payments in cash on the security during the year.
 
    CORPORATE FIXED-INCOME SECURITIES.  In order to generate the current income
needed to achieve its investment objective, the Fund may invest in investment
grade nonconvertible fixed-income securities as well as in such securities which
are in the lower rating categories of S & P and Moody's or which are not rated
by such agencies. Such investments may be deemed speculative in nature.
 
    The ratings of fixed-income securities by Moody's and S & P are a generally
accepted barometer of credit risk. The Investment Manager will primarily rely
upon such ratings in assessing the creditworthiness of the issuers of the
securities it purchases. Nevertheless, the Investment Manager takes into account
in its security selection process the fact that credit ratings evaluate the
safety of a security's continuing payments of principal and interest, rather
than the risk of decline in its market value. Moreover, as credit rating
agencies may fail to make timely changes in their credit ratings to reflect
changing circumstances and events, the Investment Manager will continuously
monitor the issuers of the lower-rated securities held in the Fund's portfolio
to determine whether these issuers have sufficient cash flow and profits to meet
required principal and interest payments.
 
    All fixed-income securities are subject to two types of risks: the credit
risk and the interest rate risk. The credit risk relates to the ability of the
issuer to meet interest or principal payments or both as they come due. The
interest rate risk refers to the fluctuations in net asset value of any
portfolio of fixed-income securities resulting from the inverse relationship
between price and yield of fixed-income securities; that is, when the general
level of interest rates rises, the prices of outstanding fixed-income securities
decline, and when interest rates fall, prices rise.
 
    FOREIGN SECURITIES.  The Fund may invest in securities of foreign companies.
However, the Fund will not invest more than 10% of the value of its total
assets, at the time of purchase, in foreign securities (other than securities of
Canadian issuers registered under the Securities Exchange Act of 1934 or
American Depository Receipts, on which there is no such limit). Foreign
securities investments may be affected by changes in currency rates or exchange
control regulations, changes in governmental administration or economic or
monetary policy (in the United States and abroad) or changed circumstances in
dealings between nations. Costs will be incurred in connection with conversions
between various currencies held by the Fund. Investments in foreign securities
will also occasion risks relating to political and economic developments abroad,
including the possibility of expropriations or confiscatory taxation,
limitations on the use or transfer of Fund assets and any effects of foreign
social, economic or political instability.
 
    WHEN-ISSUED AND DELAYED DELIVERY SECURITIES AND FORWARD COMMITMENTS.  From
time to time, in the ordinary course of business, the Fund may purchase
securities on a when-issued or delayed delivery basis or may purchase or sell
securities on a forward commitment basis. When such transactions are negotiated,
the price is fixed at the time of the commitment, but delivery and payment can
take place a month or more after the date of the commitment. While the Fund will
only purchase securities on a when-issued, delayed delivery or forward
commitment basis with the intention of acquiring the securities, the Fund may
sell the securities before the settlement date, if it is deemed advisable. The
securities so purchased or sold are subject to market fluctuation and no
interest accrues to the purchaser during this period.
 
    WHEN, AS AND IF ISSUED SECURITIES.  The Fund may purchase securities on a
"when, as and if issued" basis under which the issuance of the security depends
upon the occurrence of a subsequent event, such as approval of a merger,
corporate reorganization or debt restructuring. If the anticipated event does
not occur and the securities are not issued, the Fund will have lost an
investment opportunity. There is no overall limit on the percentage of the
Fund's assets which may be committed
 
                                       10
<PAGE>
to the purchase of securities on a "when, as and if issued" basis. An increase
in the percentage of the Fund's assets committed to the purchase of securities
on a "when, as and if issued" basis may increase the volatility of its net asset
value.
 
    PRIVATE PLACEMENTS.  The Fund may invest up to 5% of its total assets in
securities which are subject to restrictions on resale because they have not
been registered under the Securities Act of 1933, as amended (the "Securities
Act"), or which are otherwise not readily marketable. (Securities eligible for
resale pursuant to Rule 144A under the Securities Act, and determined to be
liquid pursuant to the procedures discussed in the following paragraph, are not
subject to the foregoing restriction.) These securities are generally referred
to as private placements or restricted securities. Limitations on the resale of
such securities may have an adverse effect on their marketability, and may
prevent the Fund from disposing of them promptly at reasonable prices. The Fund
may have to bear the expense of registering such securities for resale and the
risk of substantial delays in effecting such registration.
 
    The Securities and Exchange Commission has adopted Rule 144A under the
Securities Act, which permits the Fund to sell restricted securities to
qualified institutional buyers without limitation. The Investment Manager,
pursuant to procedures adopted by the Trustees of the Fund, will make a
determination as to the liquidity of each restricted security purchased by the
Fund. If a restricted security is determined to be "liquid", such security will
not be included within the category "illiquid securities", which under current
policy may not exceed 15% of the Fund's net assets. Investing in Rule 144A
securities could have the effect of increasing the level of Fund illiquidity to
the extent the Fund, at a particular time, may be unable to find qualified
institutional buyers interested in purchasing such securities.
 
    INVESTMENT IN REAL ESTATE INVESTMENT TRUSTS. The Fund may invest in real
estate investment trusts, which pool investors' funds for investments primarily
in commercial real estate properties. Investment in real estate investment
trusts may be the most practical available means for the Fund to invest in the
real estate industry (the Fund is prohibited from investing in real estate
directly). As a shareholder in a real estate investment trust, the Fund would
bear its ratable share of the real estate investment trust's expenses, including
its advisory and administration fees. At the same time the Fund would continue
to pay its own investment management fees and other expenses, as a result of
which the Fund and its shareholders in effect will be absorbing duplicate levels
of fees with respect to investments in real estate investment trusts.
 
    RIGHTS AND WARRANTS.  The Fund may acquire rights and/or warrants which are
attached to other securities in its portfolio, or which are issued as a
distribution by the issuer of a security held in its portfolio. Rights and/or
warrants are, in effect, options to purchase equity securities at a specific
price, generally valid for a specific period of time, and have no voting rights,
pay no dividends and have no rights with respect to the corporation issuing
them.
 
    REPURCHASE AGREEMENTS.  The Fund may enter into repurchase agreements, which
may be viewed as a type of secured lending by the Fund, and which typically
involve the acquisition by the Fund of government securities or other securities
from a selling financial institution such as a bank, savings and loan
association or broker-dealer. The agreement provides that the Fund will sell
back to the institution, and that the institution will repurchase, the
underlying security at a specified price and at a fixed time in the future,
usually not more than seven days from the date of purchase. While repurchase
agreements involve certain risks not associated with direct investments in debt
securities, including the risks of default or bankruptcy of the selling
financial institution, the Fund follows procedures to minimize such risks. These
procedures include effecting repurchase transactions only with large,
well-capitalized and well-established financial institutions and maintaining
adequate collateralization.
 
                                       11
<PAGE>
    LOWER-RATED SECURITIES.  Because of the special nature of the Fund's
investments in lower rated securities (certain lower rated securities in which
the Fund may invest are commonly known as junk bonds), the Investment Manager
must take account of certain special considerations in assessing the risks
associated with such investments. For example, as the lower rated securities
market is relatively new, its growth had paralleled a long economic expansion
and, until recently, it had not faced adverse economic and market conditions.
Therefore, an economic downturn or increase in interest rates is likely to have
a negative effect on this market and on the value of the lower rated securities
held by the Fund, as well as on the ability of the securities' issuers to repay
principal and interest on their borrowings.
    The prices of lower rated securities have been found to be less sensitive to
changes in prevailing interest rates than higher rated investments, but are
likely to be more sensitive to adverse economic changes or individual corporate
developments. During an economic downturn or substantial period of rising
interest rates, highly leveraged issuers may experience financial stress which
would adversely effect their ability to service their principal and interest
payment obligations, to meet their projected business goals or to obtain
additional financing. If the issuer of a fixed-income security owned by the Fund
defaults, the Fund may incur additional expenses to seek recovery. In addition,
periods of economic uncertainty and change can be expected to result in an
increased volatility of market prices of lower rated securities and a
concomitant volatility in the net asset value of a share of the Fund. Moreover,
the market prices of certain of the Fund's portfolio securities which are
structured as zero coupon and payment-in-kind securities are affected to a
greater extent by interest rate changes and thereby tend to be more volatile
than securities which pay interest periodically and in cash (see "Dividends,
Distributions and Taxes" for a discussion of the tax ramifications of
investments in such securities).
 
    The secondary market for lower rated securities may be less liquid than the
markets for higher quality securities and, as such, may have an adverse affect
on the market prices of certain securities. The limited liquidity of the market
may also adversely affect the ability of the Fund's Trustees to arrive at a fair
value for certain lower rated securities at certain times and should make it
difficult for the Fund to sell certain securities. In addition, new laws and
proposed new laws may have an adverse effect upon the value of lower rated
securities and a concomitant negative impact upon the net asset value of a share
of the Fund.
 
    During the fiscal year ended September 30, 1996, the monthly dollar weighted
average ratings of the debt obligations held by the Fund, expressed as a
percentage of the Fund's total investments, were as follows:
 
<TABLE>
<CAPTION>
                              PERCENTAGE OF
RATINGS                     TOTAL INVESTMENTS
- -------------------------  --------------------
<S>                        <C>
AAA/Aaa..................            0.0%
AA/Aa....................            1.4%
A/A......................           14.2%
BBB/Baa..................           10.2%
BB/Ba....................           19.5%
B/B......................           42.4%
CCC/Caa..................            1.2%
CC/Ca....................            0.0%
C/C......................            0.0%
Unrated..................           11.1%
</TABLE>
 
    OPTIONS AND FUTURES TRANSACTIONS.  The Fund is permitted to enter into call
and put options on U.S. Treasury notes, bonds and bills and equity securities
which are listed on Exchanges and are written in over-the-counter transactions
("OTC options"). Listed options are issued by the Options Clearing Corporation.
OTC options are purchased from or sold (written) to dealers or financial
institutions which have entered into direct agreements with the Fund. The Fund
is permitted to write covered call options on portfolio securities, in an amount
not exceeding 20% of the value of its total assets, in order to aid it in
achieving its investment objective.
 
    The Fund may purchase listed and OTC call and put options in amounts
equalling up to 5% of its total assets. The Fund may purchase call options only
in order to close out a covered call position.
 
                                       12
<PAGE>
The Fund may purchase put options on securities which it holds (or has the right
to acquire) in its portfolio only to protect itself against a decline in the
value of the security. The Fund may also purchase put options to close out
written put positions. There are no other limits on the Fund's ability to
purchase call and put options.
 
    The Fund may purchase and sell financial futures contracts ("futures
contracts") that are traded on U.S. commodity exchanges on such underlying
securities as U.S. Treasury bonds, notes, and bills. The Fund may invest in
financial futures contracts only as a hedge against anticipated interest rate
changes.
 
    The Fund may also purchase and write call and put options on futures
contracts which are traded on an Exchange and enter into closing transactions
with respect to such options to terminate an existing position. The Fund will
purchase and write options on futures contracts for identical purposes to those
set forth above for the purchase of a futures contract and the sale of a futures
contract or to close out a long or short position in futures contracts.
 
    The Fund may not enter into futures contracts or purchase related options
thereon if, immediately thereafter, the amount committed to initial margin plus
the amount paid for premiums for unexpired options on futures contracts exceeds
5% of the value of the Fund's total assets, after taking into account unrealized
gains and unrealized losses on such contracts it has entered into, provided,
however, that in the case of an option that is in-the-money (the exercise price
of the call (put) option is less (more) than the market price of the underlying
security) at the time of purchase, the in-the-money amount may be excluded in
calculating the 5%. Moreover, the Fund may only buy and write options which are
listed on national securities exchanges and may not purchase options if, as a
result, the aggregate cost of all outstanding options exceeds 10% of the Fund's
total assets. In addition, the Fund may not purchase or sell futures contracts
or related options thereon if, immediately thereafter, more than one-third of
its net assets would be hedged.
 
    RISKS OF OPTIONS AND FUTURES TRANSACTIONS. The Fund may close out its
position as writer of an option, or as a buyer or seller of a futures contract
only if a liquid secondary market exists for options or futures contracts of
that series. There is no assurance that such a market will exist particularly in
the case of OTC options, as such options generally will only be closed out by
entering into a closing purchase transaction with the purchasing dealer. Also,
exchanges may limit the amount by which the price of many futures contracts may
move on any day. If the price moves equal the daily limit on successive days,
then it may prove impossible to liquidate a futures position until the daily
limit moves have ceased.
 
    While the futures contracts and options transactions to be engaged in by the
Fund for the purpose of hedging the Fund's portfolio securities are not
speculative in nature, there are risks inherent in the use of such instruments.
One such risk is that the Investment Manager could be incorrect in its
expectations as to the direction or extent of various interest rate or price
movements or the time span within which the movements take place. For example,
if the Fund sold futures contracts for the sale of securities in anticipation of
an increase in interest rates, and then interest rates went down instead,
causing bond prices to rise, the Fund would lose money on the sale. Another risk
which may arise in employing futures contracts to protect against the price
volatility of portfolio securities is that the prices of securities and indices
subject to futures contracts (and thereby the futures contract prices) may
correlate imperfectly with the behavior of the cash prices of the Fund's
portfolio securities. See the Statement of Additional Information for further
discussion of such risks.
 
PORTFOLIO MANAGEMENT
 
    The Fund's portfolio is actively managed by its Investment Manager with a
view to achieving the Fund's investment objective. In determining which
securities to purchase for the Fund or hold in the Fund's portfolio, the
Investment Manager will rely on information from various sources, including
rating
 
                                       13
<PAGE>
   
agencies, research, analysis and appraisals of brokers and dealers, including
Dean Witter Reynolds Inc. ("DWR") and other broker-dealer affiliates of
InterCapital, others regarding economic developments and interest rate trends,
and the Investment Manager's own analysis of factors it deems relevant. The Fund
is managed within InterCapital's Growth and Income Group, which manages 22 funds
and fund portfolios with approximately $27.4 billion in assets at June 30, 1997.
Michael G. Knox, Vice President of InterCapital since May, 1995, and a member of
InterCapital's Growth and Income Group, has been the primary portfolio manager
of the Fund since November, 1994 and has been the sole portfolio manager of the
Fund since December, 1995. Mr. Knox has been managing portfolios comprised of
growth and other securities at InterCapital since August, 1993; prior thereto he
was a portfolio manager and analyst with Eagle Asset Management, Inc. (February,
1991-August, 1993).
    
 
   
    Orders for transactions in portfolio securities are placed for the Fund with
a number of brokers and dealers, including DWR and other brokers and dealers
that are affiliates of InterCapital. The Fund may incur brokerage commissions on
transactions conducted through such affiliates. Pursuant to an order of the
Securities and Exchange Commission, the Fund may effect principal transactions
in certain money market instruments with DWR.
    
 
    The portfolio trading engaged in by the Fund may result in its portfolio
turnover rate exceeding 100%. The Fund is expected to incur higher than normal
brokerage commission costs due to its portfolio turnover rate. Short-term gains
and losses taxable at ordinary income rates may result from such portfolio
transactions. See "Dividends, Distributions and Taxes" for a full discussion of
the tax implications of the Fund's trading policy. A more extensive discussion
of the Fund's portfolio brokerage policies is set forth in the Statement of
Additional Information.
 
    Except as specifically noted, all investment objectives, policies and
practices discussed above are not fundamental policies of the Fund and, as such,
may be changed without shareholder approval.
 
INVESTMENT RESTRICTIONS
- --------------------------------------------------------------------------------
 
    The investment restrictions listed below are among the restrictions that
have been adopted by the Fund as fundamental policies. Under the Investment
Company Act of 1940, as amended (the "Act"), a fundamental policy may not be
changed without the vote of a majority of the outstanding voting securities of
the Fund, as defined in the Act.
 
    The Fund may not:
 
   1. Invest more than 5% of the value of its total assets in the securities of
any one issuer (other than obligations issued or guaranteed by the United States
Government, its agencies or instrumentalities).
 
   2. Purchase more than 10% of all outstanding voting securities or any class
of securities of any one issuer. For purposes of compliance with this
restriction, the Fund will not invest in the convertible securities of any one
issuer if, upon conversion of such securities, the Fund would hold more than 10%
of the outstanding voting securities of that issuer.
 
   3. Invest more than 25% of the value of its total assets in securities of
issuers in any one industry. This restriction does not apply to obligations
issued or guaranteed by the United States Government or its agencies or
instrumentalities.
 
                                       14
<PAGE>
   4. Invest more than 5% of the value of its total assets in securities of
issuers having a record, together with predecessors, of less than three years of
continuous operation. This restriction shall not apply to any obligation of the
United States Government, its agencies or instrumentalities.
 
   5. Borrow money, except that the Fund may borrow from a bank for temporary or
emergency purposes in amounts not exceeding 5% (taken at the lower of cost or
current value) of the value of its total assets (not including the amount
borrowed).
 
   6. Invest more than 5% of the value of its total assets in warrants,
including not more than 2% of such assets in warrants not listed on either the
New York or American Stock Exchange. However, the acquisition of warrants
attached to other securities is not subject to this restriction.
 
    If a percentage restriction is adhered to at the time of investment, a later
increase or decrease in percentage resulting from a change in values of
portfolio securities or amount of total or net assets will not be considered a
violation of any of the foregoing restrictions.
 
   
    Notwithstanding any other investment policy or restriction, the Fund may
seek to achieve its investment objective by investing all or substantially all
of its assets in another investment company having substantially the same
investment objective and policies as the Fund.
    
 
PURCHASE OF FUND SHARES
- --------------------------------------------------------------------------------
 
   
GENERAL
    
 
   
    The Fund offers each class of its shares for sale to the public on a
continuous basis. Pursuant to a Distribution Agreement between the Fund and Dean
Witter Distributors Inc. (the "Distributor"), an affiliate of the Investment
Manager, shares of the Fund are distributed by the Distributor and offered by
DWR and other dealers who have entered into selected dealer agreements with the
Distributor ("Selected Broker-Dealers"). The principal executive office of the
Distributor is located at Two World Trade Center, New York, New York 10048.
    
 
   
    The Fund offers four classes of shares (each, a "Class"). Class A shares are
sold to investors with an initial sales charge that declines to zero for larger
purchases; however, Class A shares sold without an initial sales charge are
subject to a contingent deferred sales charge ("CDSC") of 1.0% if redeemed
within one year of purchase, except for certain specific circumstances. Class B
shares are sold without an initial sales charge but are subject to a CDSC
(scaled down from 5.0% to 1.0%) payable upon most redemptions within six years
after purchase. (Class B shares purchased by certain qualified employer-
sponsored benefit plans are subject to a CDSC scaled down from 2.0% to 1.0% if
redeemed within three years after purchase.) Class C shares are sold without an
initial sales charge but are subject to a CDSC of 1.0% on most redemptions made
within one year after purchase. Class D shares are sold without an initial sales
charge or CDSC and are available only to investors meeting an initial investment
minimum of $5 million, and to certain other limited categories of investors. At
the discretion of the Board of Trustees of the Fund, Class A shares may be sold
to categories of investors in addition to those set forth in this prospectus at
net asset value without a front-end sales charge, and Class D shares may be sold
to certain other categories of investors, in each case as may be described in
the then current prospectus of the Fund. See "Alternative Purchase
Arrangements--Selecting a Particular Class" for a discussion of factors to
consider in selecting which Class of shares to purchase.
    
 
   
    The minimum initial purchase is $1,000 for each Class of shares, although
Class D shares are only available to persons investing $5 million or more and to
certain other limited categories of investors. For the purpose of meeting the
minimum $5 million initial investment for Class D shares, and subject to
    
 
                                       15
<PAGE>
   
the $1,000 minimum initial investment for each Class of the Fund, an investor's
existing holdings of Class A shares of the Fund and other Dean Witter Funds that
are multiple class funds ("Dean Witter Multi-Class Funds") and shares of Dean
Witter Funds sold with a front-end sales charge ("FSC Funds") and concurrent
investments in Class D shares of the Fund and other Dean Witter Multi-Class
Funds will be aggregated. Subsequent purchases of $100 or more may be made by
sending a check, payable to Dean Witter Convertible Securities Trust, directly
to Dean Witter Trust Company (the "Transfer Agent") at P.O. Box 1040, Jersey
City, NJ 07303 or by contacting an account executive of DWR or other Selected
Broker-Dealer. When purchasing shares of the Fund, investors must specify
whether the purchase is for Class A, Class B, Class C or Class D shares. If no
Class is specified, the Transfer Agent will not process the transaction until
the proper Class is identified. The minimum initial purchase in the case of
investments through EasyInvest-SM-, an automatic purchase plan (see "Shareholder
Services"), is $100, provided that the schedule of automatic investments will
result in investments totalling $1,000 within the first twelve months. In the
case of investments pursuant to Systematic Payroll Deduction Plans (including
Individual Retirement Plans), the Fund, in its discretion, may accept
investments without regard to any minimum amounts which would otherwise be
required, if the Fund has reason to believe that additional investments will
increase the investment in all accounts under such Plans to at least $1,000.
Certificates for shares purchased will not be issued unless requested by the
shareholder in writing to the Transfer Agent.
    
 
   
    Shares of the Fund are sold through the Distributor on a normal three
business day settlement basis; that is, payment is due on the third business day
(settlement date) after the order is placed with the Distributor. Since DWR and
other Selected Broker-Dealers forward investors' funds on settlement date, they
will benefit from the temporary use of the funds if payment is made prior
thereto. As noted above, orders placed directly with the Transfer Agent must be
accompanied by payment. Investors will be entitled to receive income dividends
and capital gains distributions if their order is received by the close of
business on the day prior to the record date for such dividends and
distributions. Sales personnel of a Selected Broker-Dealer are compensated for
selling shares of the Fund by the Distributor or any of its affiliates and/or
the Selected Broker-Dealer. In addition, some sales personnel of the Selected
Broker-Dealer will receive various types of non-cash compensation as special
sales incentives, including trips, educational and/or business seminars and
merchandise. The Fund and the Distributor reserve the right to reject any
purchase orders.
    
 
   
ALTERNATIVE PURCHASE ARRANGEMENTS
    
 
   
    The Fund offers several Classes of shares to investors designed to provide
them with the flexibility of selecting an investment best suited to their needs.
The general public is offered three Classes of shares: Class A shares, Class B
shares and Class C shares, which differ principally in terms of sales charges
and rate of expenses to which they are subject. A fourth Class of shares, Class
D shares, is offered only to limited categories of investors (see "No Load
Alternative--Class D Shares" below).
    
 
   
    Each Class A, Class B, Class C or Class D share of the Fund represents an
identical interest in the investment portfolio of the Fund except that Class A,
Class B and Class C shares bear the expenses of the ongoing shareholder service
fees, Class B and Class C shares bear the expenses of the ongoing distribution
fees and Class A, Class B and Class C shares which are redeemed subject to a
CDSC bear the expense of the additional incremental distribution costs resulting
from the CDSC applicable to shares of those Classes. The ongoing distribution
fees that are imposed on Class A, Class B and Class C shares will be imposed
directly against those Classes and not against all assets of the Fund and,
accordingly, such charges against one Class will not affect the net asset value
of any
    
 
                                       16
<PAGE>
   
other Class or have any impact on investors choosing another sales charge
option. See "Plan of Distribution" and "Redemptions and Repurchases."
    
 
   
    Set forth below is a summary of the differences between the Classes and the
factors an investor should consider when selecting a particular Class. This
summary is qualified in its entirety by detailed discussion of each Class that
follows this summary.
    
 
   
    CLASS A SHARES.  Class A shares are sold at net asset value plus an initial
sales charge of up to 5.25%. The initial sales charge is reduced for certain
purchases. Investments of $1 million or more (and investments by certain other
limited categories of investors) are not subject to any sales charges at the
time of purchase but are subject to a CDSC of 1.0% on redemptions made within
one year after purchase, except for certain specific circumstances. Class A
shares are also subject to a 12b-1 fee of up to 0.25% of the average daily net
assets of the Class. See "Initial Sales Charge Alternative--Class A Shares."
    
 
   
    CLASS B SHARES.  Class B shares are offered at net asset value with no
initial sales charge but are subject to a CDSC (scaled down from 5.0% to 1.0%)
if redeemed within six years of purchase. (Class B shares purchased by certain
qualified employer-sponsored benefit plans are subject to a CDSC scaled down
from 2.0% to 1.0% if redeemed within three years after purchase.) This CDSC may
be waived for certain redemptions. Class B shares are also subject to an annual
12b-1 fee of 1.0% of the lesser of: (a) the average daily aggregate gross sales
of the Fund's Class B shares since the inception of the Fund (not including
reinvestments of dividends or capital gains distributions), less the average
daily aggregate net asset value of the Fund's Class B shares redeemed since the
Fund's inception upon which a CDSC has been imposed or waived, or (b) the
average daily net assets of Class B. The Class B shares' distribution fee will
cause that Class to have higher expenses and pay lower dividends than Class A or
Class D shares.
    
 
   
    After approximately ten (10) years, Class B shares will convert
automatically to Class A shares of the Fund, based on the relative net asset
values of the shares of the two Classes on the conversion date. In addition, a
certain portion of Class B shares that have been acquired through the
reinvestment of dividends and distributions will be converted at that time. See
"Contingent Deferred Sales Charge Alternative--Class B Shares."
    
 
   
    CLASS C SHARES.  Class C shares are sold at net asset value with no initial
sales charge but are subject to a CDSC of 1.0% on redemptions made within one
year after purchase. This CDSC may be waived for certain redemptions. They are
subject to an annual 12b-1 fee of up to 1.0% of the average daily net assets of
the Class C shares. The Class C shares' distribution fee may cause that Class to
have higher expenses and pay lower dividends than Class A or Class D shares. See
"Level Load Alternative--Class C Shares."
    
 
   
    CLASS D SHARES.  Class D shares are available only to limited categories of
investors (see "No Load Alternative--Class D Shares" below). Class D shares are
sold at net asset value with no initial sales charge or CDSC. They are not
subject to any 12b-1 fees. See "No Load Alternative--Class D Shares."
    
 
   
    SELECTING A PARTICULAR CLASS.  In deciding which Class of Fund shares to
purchase, investors should consider the following factors, as well as any other
relevant facts and circumstances:
    
 
   
    The decision as to which Class of shares is more beneficial to an investor
depends on the amount and intended length of his or her investment. Investors
who prefer an initial sales charge alternative may elect to purchase Class A
shares. Investors qualifying for significantly reduced or, in the case of
purchases of $1 million or more, no initial sales charges may find Class A
shares particularly attractive because similar sales charge reductions are not
available with respect to Class B or Class C shares. Moreover, Class A shares
are subject to lower ongoing expenses than are Class B or
    
 
                                       17
<PAGE>
   
Class C shares over the term of the investment. As an alternative, Class B and
Class C shares are sold without any initial sales charge so the entire purchase
price is immediately invested in the Fund. Any investment return on these
additional investment amounts may partially or wholly offset the higher annual
expenses of these Classes. Because the Fund's future return cannot be predicted,
however, there can be no assurance that this would be the case.
    
 
   
    Finally, investors should consider the effect of the CDSC period and any
conversion rights of the Classes in the context of their own investment time
frame. For example, although Class C shares are subject to a significantly lower
CDSC upon redemptions, they do not, unlike Class B shares, convert into Class A
shares after approximately ten years, and, therefore, are subject to an ongoing
12b-1 fee of 1.0% (rather than the 0.25% fee applicable to Class A shares) for
an indefinite period of time. Thus, Class B shares may be more attractive than
Class C shares to investors with longer term investment outlooks. Other
investors, however, may elect to purchase Class C shares if, for example, they
determine that they do not wish to be subject to a front-end sales charge and
they are uncertain as to the length of time they intend to hold their shares.
    
 
   
    For the purpose of meeting the $5 million minimum investment amount for
Class D shares, holdings of Class A shares in all Dean Witter Multi-Class Funds,
shares of FSC Funds and shares of Dean Witter Funds for which such shares have
been exchanged will be included together with the current investment amount.
    
 
   
    Sales personnel may receive different compensation for selling each Class of
shares. Investors should understand that the purpose of a CDSC is the same as
that of the initial sales charge in that the sales charges applicable to each
Class provide for the financing of the distribution of shares of that Class.
    
 
   
    Set forth below is a chart comparing the sales charge, 12b-1 fees and
conversion options applicable to each Class of shares:
    
 
   
<TABLE>
<CAPTION>
<C>        <S>              <C>         <C>
                                         CONVERSION
  CLASS     SALES CHARGE    12B-1 FEE      FEATURE
    A      Maximum 5.25%        0.25%        No
           initial sales
           charge reduced
           for purchases
           of $25,000 and
           over; shares
           sold without an
           initial sales
           charge
           generally
           subject to a
           1.0% CDSC
           during first
           year.
    B      Maximum 5.0%        1.0%     B shares
           CDSC during the              convert to A
           first year                   shares
           decreasing to 0              automatically
           after six years              after
                                        approximately
                                        ten years
    C      1.0% CDSC           1.0%          No
           during first
           year
    D           None           None          No
</TABLE>
    
 
   
    See "Purchase of Fund Shares" and "The Fund and its Management" for a
complete description of the sales charges and service and distribution fees for
each Class of shares and "Determination of Net Asset Value," "Dividends,
Distributions and Taxes" and "Shareholder Services--Exchange Privilege" for
other differences between the Classes of shares.
    
 
   
INITIAL SALES CHARGE ALTERNATIVE--CLASS A SHARES
    
 
   
    Class A shares are sold at net asset value plus an initial sales charge. In
some cases, reduced sales charges may be available, as described below.
Investments of $1 million or more (and investments by certain other limited
categories of investors) are not subject to any sales charges at the time of
purchase but are subject to a CDSC of 1.0% on redemptions made within one year
after purchase (calculated from the last day of the month
    
 
                                       18
<PAGE>
   
in which the shares were purchased), except for certain specific circumstances.
The CDSC will be assessed on an amount equal to the lesser of the current market
value or the cost of the shares being redeemed. The CDSC will not be imposed (i)
in the circumstances set forth below in the section "Contingent Deferred Sales
Charge Alternative--Class B Shares--CDSC Waivers," except that the references to
six years in the first paragraph of that section shall mean one year in the case
of Class A shares, and (ii) in the circumstances identified in the section
"Additional Net Asset Value Purchase Options" below. Class A shares are also
subject to an annual 12b-1 fee of up to 0.25% of the average daily net assets of
the Class.
    
 
   
    The offering price of Class A shares will be the net asset value per share
next determined following receipt of an order (see "Determination of Net Asset
Value" below), plus a sales charge (expressed as a percentage of the offering
price) on a single transaction as shown in the following table:
    
 
   
<TABLE>
<CAPTION>
                                          SALES CHARGE
                           ------------------------------------------
                              PERCENTAGE OF          APPROXIMATE
    AMOUNT OF SINGLE         PUBLIC OFFERING    PERCENTAGE OF AMOUNT
       TRANSACTION                PRICE               INVESTED
- -------------------------  -------------------  ---------------------
<S>                        <C>                  <C>
Less than $25,000........           5.25%                 5.44%
$25,000 but less
     than $50,000........           4.75%                 4.99%
$50,000 but less
     than $100,000.......           4.00%                 4.17%
$100,000 but less
     than $250,000.......           3.00%                 3.09%
$250,000 but less
     than $1 million.....           2.00%                 2.04%
$1 million and over......              0                     0
</TABLE>
    
 
   
    Upon notice to all Selected Broker-Dealers, the Distributor may reallow up
to the full applicable sales charge as shown in the above schedule during
periods specified in such notice. During periods when 90% or more of the sales
charge is reallowed, such Selected Broker-Dealers may be deemed to be
underwriters as that term is defined in the Securities Act of 1933.
    
 
   
    The above schedule of sales charges is applicable to purchases in a single
transaction by, among others: (a) an individual; (b) an individual, his or her
spouse and their children under the age of 21 purchasing shares for his, her or
their own accounts; (c) a trustee or other fiduciary purchasing shares for a
single trust estate or a single fiduciary account; (d) a pension, profit-sharing
or other employee benefit plan qualified or non-qualified under Section 401 of
the Internal Revenue Code; (e) tax-exempt organizations enumerated in Section
501(c)(3) or (13) of the Internal Revenue Code; (f) employee benefit plans
qualified under Section 401 of the Internal Revenue Code of a single employer or
of employers who are "affiliated persons" of each other within the meaning of
Section 2(a)(3)(c) of the Act; and for investments in Individual Retirement
Accounts of employees of a single employer through Systematic Payroll Deduction
plans; or (g) any other organized group of persons, whether incorporated or not,
provided the organization has been in existence for at least six months and has
some purpose other than the purchase of redeemable securities of a registered
investment company at a discount.
    
 
   
    COMBINED PURCHASE PRIVILEGE.  Investors may have the benefit of reduced
sales charges in accordance with the above schedule by combining purchases of
Class A shares of the Fund in single transactions with the purchase of Class A
shares of other Dean Witter Multi-Class Funds and shares of FSC Funds. The sales
charge payable on the purchase of the Class A shares of the Fund, the Class A
shares of the other Dean Witter Multi-Class Funds and the shares of the FSC
Funds will be at their respective rates applicable to the total amount of the
combined concurrent purchases of such shares.
    
 
   
    RIGHT OF ACCUMULATION.  The above persons and entities may benefit from a
reduction of the sales charges in accordance with the above schedule if the
cumulative net asset value of Class A shares purchased in a single transaction,
together with shares of the Fund and other Dean Witter Funds previously
purchased at a price including a front-end sales charge (including shares of the
Fund and other Dean Witter Funds acquired in exchange for those shares, and
including in each
    
 
                                       19
<PAGE>
   
case shares acquired through reinvestment of dividends and distributions), which
are held at the time of such transaction, amounts to $25,000 or more. If such
investor has a cumulative net asset value of shares of FSC Funds and Class A and
Class D shares equal to at least $5 million, such investor is eligible to
purchase Class D shares subject to the $1,000 minimum initial investment
requirement of that Class of the Fund. See "No Load Alternative-- Class D
Shares" below.
    
 
   
    The Distributor must be notified by DWR or a Selected Broker-Dealer or the
shareholder at the time a purchase order is placed that the purchase qualifies
for the reduced charge under the Right of Accumulation. Similar notification
must be made in writing by the dealer or shareholder when such an order is
placed by mail. The reduced sales charge will not be granted if: (a) such
notification is not furnished at the time of the order; or (b) a review of the
records of the Selected Broker-Dealer or the Transfer Agent fails to confirm the
investor's represented holdings.
    
 
   
    LETTER OF INTENT.  The foregoing schedule of reduced sales charges will also
be available to investors who enter into a written Letter of Intent providing
for the purchase, within a thirteen-month period, of Class A shares of the Fund
from DWR or other Selected Broker-Dealers. The cost of Class A shares of the
Fund or shares of other Dean Witter Funds which were previously purchased at a
price including a front-end sales charge during the 90-day period prior to the
date of receipt by the Distributor of the Letter of Intent, or of Class A shares
of the Fund or shares of other Dean Witter Funds acquired in exchange for shares
of such funds purchased during such period at a price including a front-end
sales charge, which are still owned by the shareholder, may also be included in
determining the applicable reduction.
    
 
   
    ADDITIONAL NET ASSET VALUE PURCHASE OPTIONS. In addition to investments of
$1 million or more, Class A shares also may be purchased at net asset value by
the following:
    
 
   
   (1) trusts for which Dean Witter Trust Company ("DWTC") or Dean Witter Trust
FSB ("DWTFSB") (each of which is an affiliate of the Investment Manager)
provides discretionary trustee services;
    
 
   
   (2) persons participating in a fee-based program approved by the Distributor,
pursuant to which such persons pay an asset based fee for services in the nature
of investment advisory or administrative services (such investments are subject
to all of the terms and conditions of such programs, which may include
termination fees and restrictions on transferability of Fund shares);
    
 
   
   (3) retirement plans qualified under Section 401(k) of the Internal Revenue
Code ("401(k) plans") and other employer-sponsored plans qualified under Section
401(a) of the Internal Revenue Code with at least 200 eligible employees and for
which DWTC or DWTFSB serves as Trustee or the 401(k) Support Services Group of
DWR serves as recordkeeper;
    
 
   
   (4) 401(k) plans and other employer-sponsored plans qualified under Section
401(a) of the Internal Revenue Code for which DWTC or DWTFSB serves as Trustee
or the 401(k) Support Services Group of DWR serves as recordkeeper whose Class B
shares have converted to Class A shares, regardless of the plan's asset size or
number of eligible employees;
    
 
   
   (5) investors who are clients of a Dean Witter account executive who joined
Dean Witter from another investment firm within six months prior to the date of
purchase of Fund shares by such investors, if the shares are being purchased
with the proceeds from a redemption of shares of an open-end proprietary mutual
fund of the account executive's previous firm which imposed either a front-end
or deferred sales charge, provided such purchase was made within sixty days
after the redemption and the proceeds of the redemption had been maintained in
the interim in cash or a money market fund; and
    
 
   
   (6) other categories of investors, at the discretion of the Board, as
disclosed in the then current prospectus of the Fund.
    
 
                                       20
<PAGE>
   
    No CDSC will be imposed on redemptions of shares purchased pursuant to
paragraphs (1), (2) or (5), above.
    
 
   
    For further information concerning purchases of the Fund's shares, contact
DWR or another Selected Broker-Dealer or consult the Statement of Additional
Information.
    
 
   
CONTINGENT DEFERRED SALES CHARGE ALTERNATIVE-- CLASS B SHARES
    
 
   
    Class B shares are sold at net asset value next determined without an
initial sales charge so that the full amount of an investor's purchase payment
may be immediately invested in the Fund. A CDSC, however, will be imposed on
most Class B shares redeemed within six years after purchase. The CDSC will be
imposed on any redemption of shares if after such redemption the aggregate
current value of a Class B account with the Fund falls below the aggregate
amount of the investor's purchase payments for Class B shares made during the
six years (or, in the case of shares held by certain employer-sponsored benefit
plans, three years) preceding the redemption. In addition, Class B shares are
subject to an annual 12b-1 fee of 1.0% of the lesser of: (a) the average daily
aggregate gross sales of the Fund's Class B shares since the inception of the
Fund (not including reinvestments of dividends or capital gains distributions),
less the average daily aggregate net asset value of the Fund's Class B shares
redeemed since the Fund's inception upon which a CDSC has been imposed or
waived, or (b) the average daily net assets of Class B.
    
 
   
    Except as noted below, Class B shares of the Fund which are held for six
years or more after purchase (calculated from the last day of the month in which
the shares were purchased) will not be subject to any CDSC upon redemption.
Shares redeemed earlier than six years after purchase may, however, be subject
to a CDSC which will be a percentage of the dollar amount of shares redeemed and
will be assessed on an amount equal to the lesser of the current market value or
the cost of the shares being redeemed. The size of this percentage will depend
upon how long the shares have been held, as set forth in the following table:
    
 
   
<TABLE>
<CAPTION>
           YEAR SINCE                     CDSC AS A
            PURCHASE                    PERCENTAGE OF
          PAYMENT MADE                 AMOUNT REDEEMED
- ---------------------------------  -----------------------
<S>                                <C>
First............................              5.0%
Second...........................              4.0%
Third............................              3.0%
Fourth...........................              2.0%
Fifth............................              2.0%
Sixth............................              1.0%
Seventh and thereafter...........              None
</TABLE>
    
 
   
    In the case of Class B shares of the Fund held by 401 (k) plans or other
employer-sponsored plans qualified under Section 401(a) of the Internal Revenue
Code for which DWTC or DWTFSB serves as Trustee or the 401(k) Support Services
Group of DWR serves as recordkeeper and whose accounts are opened on or after
July 28, 1997, shares held for three years or more after purchase (calculated as
described in the paragraph above) will not be subject to any CDSC upon
redemption. However, shares redeemed earlier than three years after purchase may
be subject to a CDSC (calculated as described in the paragraph above), the
percentage of which will depend on how long the shares have been held, as set
forth in the following table:
    
 
   
<TABLE>
<CAPTION>
           YEAR SINCE
            PURCHASE               CDSC AS A PERCENTAGE OF
          PAYMENT MADE                 AMOUNT REDEEMED
- ---------------------------------  -----------------------
<S>                                <C>
First............................              2.0%
Second...........................              2.0%
Third............................              1.0%
Fourth and thereafter............              None
</TABLE>
    
 
   
    CDSC WAIVERS.  A CDSC will not be imposed on: (i) any amount which
represents an increase in value of shares purchased within the six years (or, in
the case of shares held by certain employer-sponsored benefit plans, three
years) preceding the redemption; (ii) the current net asset value of shares
purchased more than six years (or, in the case of shares held by certain
employer-sponsored benefit plans, three years) prior to the redemption; and
(iii) the current net asset value of shares purchased
    
 
                                       21
<PAGE>
   
through reinvestment of dividends or distributions and/or shares acquired in
exchange for shares of FSC Funds or of other Dean Witter Funds acquired in
exchange for such shares. Moreover, in determining whether a CDSC is applicable
it will be assumed that amounts described in (i), (ii) and (iii) above (in that
order) are redeemed first. In addition, no CDSC will be imposed on redemptions
of shares which are attributable to reinvestment of dividends or distributions
from, or the proceeds of, certain Unit Investment Trusts.
    
 
   
    In addition, the CDSC, if otherwise applicable, will be waived in the case
of:
    
 
   
   (1) redemptions of shares held at the time a shareholder dies or becomes
disabled, only if the shares are:  (A) registered either in the name of an
individual shareholder (not a trust), or in the names of such shareholder and
his or her spouse as joint tenants with right of survivorship; or  (B) held in a
qualified corporate or self-employed retirement plan, Individual Retirement
Account ("IRA") or Custodial Account under Section 403(b)(7) of the Internal
Revenue Code ("403(b) Custodial Account"), provided in either case that the
redemption is requested within one year of the death or initial determination of
disability;
    
 
   
   (2) redemptions in connection with the following retirement plan
distributions:  (A) lump-sum or other distributions from a qualified corporate
or self-employed retirement plan following retirement (or, in the case of a "key
employee" of a "top heavy" plan, following attainment of age 59 1/2); (B)
distributions from an IRA or 403(b) Custodial
Account following attainment of age 59 1/2; or  (C) a tax-free return of an
excess contribution to an IRA; and
    
 
   
   (3) all redemptions of shares held for the benefit of a participant in a
401(k) plan or other employer-sponsored plan qualified under Section 401(a) of
the Internal Revenue Code which offers investment companies managed by the
Investment Manager or its subsidiary, Dean Witter Services Company Inc., as
self-directed investment alternatives and for which DWTC or DWTFSB serves as
Trustee or the 401(k) Support Services Group of DWR serves as recordkeeper
("Eligible Plan"), provided that either:  (a) the plan continues to be an
Eligible Plan after the redemption; or  (b) the redemption is in connection with
the complete termination of the plan involving the distribution of all plan
assets to participants.
    
 
   
    With reference to (1) above, for the purpose of determining disability, the
Distributor utilizes the definition of disability contained in Section 72(m)(7)
of the Internal Revenue Code, which relates to the inability to engage in
gainful employment. With reference to (2) above, the term "distribution" does
not encompass a direct transfer of IRA, 403(b) Custodial Account or retirement
plan assets to a successor custodian or trustee. All waivers will be granted
only following receipt by the Distributor of confirmation of the shareholder's
entitlement.
    
 
   
    CONVERSION TO CLASS A SHARES.  All shares of the Fund held prior to July 28,
1997 have been designated Class B shares. Shares held before May 1, 1997 will
convert to Class A shares in May, 2007. In all other instances Class B shares
will convert automatically to Class A shares, based on the relative net asset
values of the shares of the two Classes on the conversion date, which will be
approximately ten (10) years after the date of the original purchase. The ten
year period is calculated from the last day of the month in which the shares
were purchased or, in the case of Class B shares acquired through an exchange or
a series of exchanges, from the last day of the month in which the original
Class B shares were purchased, provided that shares originally purchased before
May 1, 1997 will convert to Class A shares in May, 2007. The conversion of
shares purchased on or after May 1, 1997 will take place in the month following
the tenth anniversary of the purchase. There will also be converted at that time
such proportion of Class B shares acquired through automatic reinvestment of
dividends and distributions owned by the shareholder as the total number of his
or her Class B shares converting at the time bears to the
    
 
                                       22
<PAGE>
   
total number of outstanding Class B shares purchased and owned by the
shareholder. In the case of Class B shares held by a 401(k) plan or other
employer-sponsored plan qualified under Section 401(a) of the Internal Revenue
Code and for which DWTC or DWTFSB serves as Trustee or the 401(k) Support
Services Group of DWR serves as recordkeeper, the plan is treated as a single
investor and all Class B shares will convert to Class A shares on the conversion
date of the first shares of a Dean Witter Multi-Class Fund purchased by that
plan. In the case of Class B shares previously exchanged for shares of an
"Exchange Fund" (see "Shareholder Services--Exchange Privilege"), the period of
time the shares were held in the Exchange Fund (calculated from the last day of
the month in which the Exchange Fund shares were acquired) is excluded from the
holding period for conversion. If those shares are subsequently re-exchanged for
Class B shares of a Dean Witter Multi-Class Fund, the holding period resumes on
the last day of the month in which Class B shares are reacquired.
    
 
   
    If a shareholder has received share certificates for Class B shares, such
certificates must be delivered to the Transfer Agent at least one week prior to
the date for conversion. Class B shares evidenced by share certificates that are
not received by the Transfer Agent at least one week prior to any conversion
date will be converted into Class A shares on the next scheduled conversion date
after such certificates are received.
    
 
   
    Effectiveness of the conversion feature is subject to the continuing
availability of a ruling of the Internal Revenue Service or an opinion of
counsel that (i) the conversion of shares does not constitute a taxable event
under the Internal Revenue Code, (ii) Class A shares received on conversion will
have a basis equal to the shareholder's basis in the converted Class B shares
immediately prior to the conversion, and (iii) Class A shares received on
conversion will have a holding period that includes the holding period of the
converted Class B shares. The conversion feature may be suspended if the ruling
or opinion is no longer available. In such event, Class B shares would continue
to be subject to Class B 12b-1 fees.
    
 
   
    Class B shares purchased before July 28, 1997 by trusts for which DWTC or
DWTFSB provides discretionary trustee services will convert to Class A shares on
or about August 29, 1997. The CDSC will not be applicable to such shares.
    
 
   
LEVEL LOAD ALTERNATIVE--CLASS C SHARES
    
 
   
    Class C shares are sold at net asset value next determined without an
initial sales charge but are subject to a CDSC of 1.0% on most redemptions made
within one year after purchase (calculated from the last day of the month in
which the shares were purchased). The CDSC will be assessed on an amount equal
to the lesser of the current market value or the cost of the shares being
redeemed. The CDSC will not be imposed in the circumstances set forth above in
the section "Contingent Deferred Sales Charge Alternative--Class B Shares--CDSC
Waivers," except that the references to six years in the first paragraph of that
section shall mean one year in the case of Class C shares. Class C shares are
subject to an annual 12b-1 fee of up to 1.0% of the average daily net assets of
the Class. Unlike Class B shares, Class C shares have no conversion feature and,
accordingly, an investor that purchases Class C shares will be subject to 12b-1
fees applicable to Class C shares for an indefinite period subject to annual
approval by the Fund's Board of Trustees and regulatory limitations.
    
 
   
NO LOAD ALTERNATIVE--CLASS D SHARES
    
 
   
    Class D shares are offered without any sales charge on purchase or
redemption and without any 12b-1 fee. Class D shares are offered only to
investors meeting an initial investment minimum of $5 million and the following
categories of investors: (i) investors participating in the InterCapital mutual
fund asset allocation program pursuant to which such persons pay an asset based
fee; (ii) persons participating in a fee-based program approved by the
Distributor, pursuant to which such persons pay an asset based fee for services
in the nature of investment advisory or administrative services
    
(sub-
 
                                       23
<PAGE>
   
ject to all of the terms and conditions of such programs, which may include
termination fees and restrictions on transferability of Fund shares); (iii)
401(k) plans established by DWR and SPS Transaction Services, Inc. (an affiliate
of DWR) for their employees; (iv) certain Unit Investment Trusts sponsored by
DWR; (v) certain other open-end investment companies whose shares are
distributed by the Distributor; and (vi) other categories of investors, at the
discretion of the Board, as disclosed in the then current prospectus of the
Fund. Investors who require a $5 million minimum initial investment to qualify
to purchase Class D shares may satisfy that requirement by investing that amount
in a single transaction in Class D shares of the Fund and other Dean Witter
Multi-Class Funds, subject to the $1,000 minimum initial investment required for
that Class of the Fund. In addition, for the purpose of meeting the $5 million
minimum investment amount, holdings of Class A shares in all Dean Witter
Multi-Class Funds, shares of FSC Funds and shares of Dean Witter Funds for which
such shares have been exchanged will be included together with the current
investment amount. If a shareholder redeems Class A shares and purchases Class D
shares, such redemption may be a taxable event.
    
 
   
PLAN OF DISTRIBUTION
    
 
   
    The Fund has adopted a Plan of Distribution pursuant to Rule 12b-1 under the
Act with respect to the distribution of Class A, Class B and Class C shares of
the Fund. In the case of Class A and Class C shares, the Plan provides that the
Fund will reimburse the Distributor and others for the expenses of certain
activities and services incurred by them specifically on behalf of those shares.
Reimbursements for these expenses will be made in monthly payments by the Fund
to the Distributor, which will in no event exceed amounts equal to payments at
the annual rates of 0.25% and 1.0% of the average daily net assets of Class A
and Class C, respectively. In the case of Class B shares, the Plan provides that
the Fund will pay the Distributor a fee, which is accrued daily and paid
monthly, at the annual rate of 1.0% of the lesser of: (a) the average daily
aggregate gross sales of the Fund's Class B shares since the inception of the
Fund (not including reinvestments of dividends or capital gains distributions),
less the average daily aggregate net asset value of the Fund's Class B shares
redeemed since the Fund's inception upon which a CDSC has been imposed or
waived, or (b) the average daily net assets of Class B. The fee is treated by
the Fund as an expense in the year it is accrued. In the case of Class A shares,
the entire amount of the fee currently represents a service fee within the
meaning of the NASD guidelines. In the case of Class B and Class C shares, a
portion of the fee payable pursuant to the Plan, equal to 0.25% of the average
daily net assets of each of these Classes, respectively, is currently
characterized as a service fee. A service fee is a payment made for personal
service and/or the maintenance of shareholder accounts.
    
 
   
    Additional amounts paid under the Plan in the case of Class B and Class C
shares are paid to the Distributor for services provided and the expenses borne
by the Distributor and others in the distribution of the shares of those
Classes, including the payment of commissions for sales of the shares of those
Classes and incentive compensation to and expenses of DWR's account executives
and others who engage in or support distribution of shares or who service
shareholder accounts, including overhead and telephone expenses; printing and
distribution of prospectuses and reports used in connection with the offering of
the Fund's shares to other than current shareholders; and preparation, printing
and distribution of sales literature and advertising materials. In addition, the
Distributor may utilize fees paid pursuant to the Plan in the case of Class B
shares to compensate DWR and other Selected Broker-Dealers for their opportunity
costs in advancing such amounts, which compensation would be in the form of a
carrying charge on any unreimbursed expenses.
    
 
    For the fiscal year ended September 30, 1996, Class B shares of the Fund
accrued payments under the Plan amounting to $2,057,104, which
 
                                       24
<PAGE>
   
amount is equal to 1.0% of the Fund's average daily net assets for the fiscal
year. The payments accrued under the Plan were calculated pursuant to clause (b)
of the compensation formula under the Plan. All shares held prior to July 28,
1997 have been designated Class B shares.
    
 
   
    In the case of Class B shares, at any given time, the expenses in
distributing Class B shares of the Fund may be in excess of the total of (i) the
payments made by the Fund pursuant to the Plan, and (ii) the proceeds of CDSCs
paid by investors upon the redemption of Class B shares. For example, if $1
million in expenses in distributing Class B shares of the Fund had been incurred
and $750,000 had been received as described in (i) and (ii) above, the excess
expense would amount to $250,000. The Distributor has advised the Fund that such
excess amounts, including the carrying charge described above, totalled
$71,800,910 at September 30, 1996, which was equal to 30.64% of the net assets
of the Fund on such date. Of this amount, $1,471,908 represents excess
distribution expenses of TCW/DW Global Convertible Trust, the net assets of
which were combined with those of the Fund on December 22, 1995 as pursuant to
an Agreement and Plan of Reorganization. Because there is no requirement under
the Plan that the Distributor be reimbursed for all distribution expenses or any
requirement that the Plan be continued from year to year, such excess amount
does not constitute a liability of the Fund. Although there is no legal
obligation for the Fund to pay expenses incurred in excess of payments made to
the Distributor under the Plan, and the proceeds of CDSCs paid by investors upon
redemption of shares, if for any reason the Plan is terminated the Trustees will
consider at that time the manner in which to treat such expenses. Any cumulative
expenses incurred, but not yet recovered through distribution fees or CDSCs, may
or may not be recovered through future distribution fees or CDSCs.
    
 
   
    In the case of Class A and Class C shares, expenses incurred pursuant to the
Plan in any calendar year in excess of 0.25% or 1.0% of the average daily net
assets of Class A or Class C, respectively, will not be reimbursed by the Fund
through payments in any subsequent year, except that expenses representing a
gross sales commission credited to account executives at the time of sale may be
reimbursed in the subsequent calendar year. No interest or other financing
charges will be incurred on any Class A or Class C distribution expenses
incurred by the Distributor under the Plan or on any unreimbursed expenses due
to the Distributor pursuant to the Plan.
    
 
DETERMINATION OF NET ASSET VALUE
 
   
    The net asset value per share is determined once daily at 4:00 p.m., New
York time, on each day that the New York Stock Exchange is open, or, on days
when the New York Stock Exchange closes prior to 4:00 p.m., at such earlier
time, by taking the net assets of the Fund, dividing by the number of shares
outstanding and adjusting to the nearest cent. The assets belonging to the Class
A, Class B, Class C and Class D shares will be invested together in a single
portfolio. The net asset value of each Class, however, will be determined
separately by subtracting each Class's accrued expenses and liabilities. The net
asset value per share will not be determined on Good Friday and on such other
federal and non-federal holidays as are observed by the New York Stock Exchange.
    
 
    In the calculation of the Fund's net asset value: (1) an equity portfolio
security listed or traded on the New York or American Stock Exchange or other
domestic or foreign exchange is valued at its latest sale price on that exchange
prior to the time assets are valued; if there were no sales that day, the
security is valued at the latest bid price (in cases where a security is traded
on more than one exchange, the security is valued on the exchange designated as
the primary market pursuant to procedures adopted by the Trustees), and (2) all
other portfolio securities for which over-the-counter market quotations are
readily available are valued at the latest bid price. When market quotations are
not readily available, or when it is determined by the Investment Manager that
sale or
 
                                       25
<PAGE>
bid prices are not reflective of a security's fair value, portfolio securities
are valued at their fair value as determined in good faith under procedures
established by and under the general supervision of the Fund's Trustees.
 
    Short-term debt securities with remaining maturities of sixty days or less
at the time of purchase are valued at amortized cost, unless the Trustees
determine such does not reflect the securities' market value, in which case
these securities will
 
be valued at their fair value as determined by the Trustees.
 
    Certain of the Fund's portfolio securities may be valued by an outside
pricing service approved by the Fund's Trustees. The pricing service may utilize
a matrix system incorporating security quality, maturity and coupon as the
evaluation model parameters, and/or research evaluations by its staff, including
review of broker-dealer market price quotations in determining what it believes
is the fair valuation of the portfolio securities valued by such pricing
service.
 
SHAREHOLDER SERVICES
- --------------------------------------------------------------------------------
 
   
    AUTOMATIC INVESTMENT OF DIVIDENDS AND DISTRIBUTIONS.  All income dividends
and capital gains distributions are automatically paid in full and fractional
shares of the applicable Class of the Fund (or, if specified by the shareholder,
in shares of any other open-end Dean Witter Fund), unless the shareholder
requests that they be paid in cash. Shares so acquired are acquired at net asset
value and are not subject to the imposition of a front-end sales charge or a
CDSC (see "Redemptions and Repurchases").
    
 
   
    INVESTMENT OF DIVIDENDS AND DISTRIBUTIONS RECEIVED IN CASH.  Any shareholder
who receives a cash payment representing a dividend or capital gains
distribution may invest such dividend or distribution in shares of the
applicable Class at the net asset value per share next determined after receipt
by the Transfer Agent, by returning the check or the proceeds to the Transfer
Agent within thirty days after the payment date. Shares so acquired are acquired
at net asset value and are not subject to the imposition of a front-end sales
charge or a CDSC (see "Redemptions and Repurchases.")
    
 
   
    EASYINVEST-SM-.  Shareholders may subscribe to EasyInvest, an automatic
purchase plan which provides for any amount from $100 to $5,000 to be
transferred automatically from a checking or savings account or following
redemption of shares of a Dean Witter money market fund, on a semi-monthly,
monthly or quarterly basis, to the Transfer Agent for investment in shares of
the Fund (see "Purchase of Fund Shares" and "Redemptions and
Repurchases--Involuntary Redemption").
    
 
   
    SYSTEMATIC WITHDRAWAL PLAN.  A systematic withdrawal plan (the "Withdrawal
Plan") is available for shareholders who own or purchase shares of the Fund
having a minimum value of $10,000 based upon the then current net asset value.
The Withdrawal Plan provides for monthly or quarterly (March, June, September
and December) checks in any dollar amount, not less than $25, or in any whole
percentage of the account balance, on an annualized basis. Any applicable CDSC
will be imposed on shares redeemed under the Withdrawal Plan (see "Purchase of
Fund Shares"). Therefore, any shareholder participating in the Withdrawal Plan
will have sufficient shares redeemed from his or her account so that the
proceeds (net of any applicable CDSC) to the shareholder will be the designated
monthly or quarterly amount. Withdrawal plan payments should not be considered
as dividends, yields or income. If periodic withdrawal plan payments
continuously exceed net investment income and net capital gains, the
shareholder's original investment will be correspondingly reduced and ultimately
exhausted. Each withdrawal constitutes a redemption of shares and any gain or
loss realized must be recognized for federal income tax purposes.
    
 
                                       26
<PAGE>
   
    Shareholders should contact their DWR or other Selected Broker-Dealer
account executive or the Transfer Agent for further information about any of the
above services.
    
 
    TAX-SHELTERED RETIREMENT PLANS.  Retirement plans are available through the
Distributor for use by corporations, the self-employed, Individual Retirement
Accounts and Custodial Accounts under Section 403(b)(7) of the Internal Revenue
Code. Adoption of such plans should be on advice of legal counsel or tax
adviser.
 
    For further information regarding plan administration, custodial fees and
other details, investors should contact their DWR or other Selected Broker-
Dealer account executive or the Transfer Agent.
 
EXCHANGE PRIVILEGE
 
   
    Shares of each Class may be exchanged for shares of the same Class of any
other Dean Witter Multi-Class Fund without the imposition of any exchange fee.
Shares may also be exchanged for shares of the following funds: Dean Witter
Short-Term U.S. Treasury Trust, Dean Witter Limited Term Municipal Trust, Dean
Witter Short-Term Bond Fund, Dean Witter Intermediate Term U.S. Treasury Trust
and five Dean Witter funds which are money market funds (the "Exchange Funds").
Class A shares may also be exchanged for shares of Dean Witter Multi-State
Municipal Series Trust and Dean Witter Hawaii Municipal Trust, which are Dean
Witter Funds sold with a front-end sales charge ("FSC Funds"). Class B shares
may also be exchanged for shares of Dean Witter Global Short-Term Income Fund
Inc., Dean Witter High Income Securities and Dean Witter National Municipal
Trust, which are Dean Witter Funds offered with a CDSC ("CDSC Funds"). Exchanges
may be made after the shares of the Fund acquired by purchase (not by exchange
or dividend reinvestment) have been held for thirty days. There is no waiting
period for exchanges of shares acquired by exchange or dividend reinvestment.
    
 
   
    An exchange to another Dean Witter Multi-Class Fund, any FSC Fund, any CDSC
Fund or any Exchange Fund that is not a money market fund is on the basis of the
next calculated net asset value per share of each fund after the exchange order
is received. When exchanging into a money market fund from the Fund, shares of
the Fund are redeemed out of the Fund at their next calculated net asset value
and the proceeds of the redemption are used to purchase shares of the money
market fund at their net asset value determined the following business day.
Subsequent exchanges between any of the money market funds and any of the Dean
Witter Multi-Class Funds, FSC Funds or CDSC Funds or any Exchange Fund that is
not a money market fund can be effected on the same basis.
    
 
   
    No CDSC is imposed at the time of any exchange of shares, although any
applicable CDSC will be imposed upon ultimate redemption. During the period of
time the shareholder remains in an Exchange Fund (calculated from the last day
of the month in which the Exchange Fund shares were acquired), the holding
period (for the purpose of determining the rate of the CDSC) is frozen. If those
shares are subsequently re-exchanged for shares of a Dean Witter Multi-Class
Fund or shares of a CDSC Fund, the holding period previously frozen when the
first exchange was made resumes on the last day of the month in which shares of
a Dean Witter Multi-Class Fund or shares of a CDSC Fund are reacquired. Thus,
the CDSC is based upon the time (calculated as described above) the shareholder
was invested in shares of a Dean Witter Multi-Class Fund or in shares of a CDSC
Fund (see "Purchase of Fund Shares"). In the case of exchanges of Class A shares
which are subject to a CDSC, the holding period also includes the time
(calculated as described above) the shareholder was invested in shares of a FSC
Fund. However, in the case of shares exchanged into an Exchange Fund on or after
April 23, 1990, upon a redemption of shares which results in a CDSC being
imposed, a credit (not to exceed the amount of the CDSC) will be given in an
amount equal to the Exchange Fund 12b-1 distribution fees incurred on or after
that date which are attributable to those shares. (Exchange Fund 12b-1
distribution fees are described in the
    
 
                                       27
<PAGE>
   
prospectuses for those funds.) Class B shares of the Fund acquired in exchange
for Class B shares of another Dean Witter Multi-Class Fund or shares of a CDSC
Fund having a different CDSC schedule than that of this Fund will be subject to
the higher CDSC schedule, even if such shares are subsequently re-exchanged for
shares of the fund with the lower CDSC schedule.
    
 
   
    ADDITIONAL INFORMATION REGARDING EXCHANGES. Purchases and exchanges should
be made for investment purposes only. A pattern of frequent exchanges may be
deemed by the Investment Manager to be abusive and contrary to the best
interests of the Fund's other shareholders and, at the Investment Manager's
discretion, may be limited by the Fund's refusal to accept additional purchases
and/ or exchanges from the investor. Although the Fund does not have any
specific definition of what constitutes a pattern of frequent exchanges, and
will consider all relevant factors in determining whether a particular situation
is abusive and contrary to the best interests of the Fund and its other
shareholders, investors should be aware that the Fund and each of the other Dean
Witter Funds may in their discretion limit or otherwise restrict the number of
times this Exchange Privilege may be exercised by any investor. Any such
restriction will be made by the Fund on a prospective basis only, upon notice to
the shareholder not later than ten days following such shareholder's most recent
exchange. Also the Exchange Privilege may be terminated or revised at any time
by the Fund and/or any of such Dean Witter Funds for which shares of the Fund
have been exchanged, upon such notice as may be required by applicable
regulatory agencies. Shareholders maintaining margin accounts with DWR or
another Selected Broker-Dealer are referred to their account executive regarding
restrictions on exchange of shares of the Fund pledged in the margin account.
    
 
   
    The current prospectus for each fund describes its investment objective(s)
and policies, and shareholders should obtain a copy and examine it carefully
before investing. Exchanges are subject to the minimum investment requirement of
each Class of shares and any other conditions imposed by each fund. In the case
of a shareholder holding a share certificate or certificates, no exchanges may
be made until all applicable share certificates have been received by the
Transfer Agent and deposited in the shareholder's account. An exchange will be
treated for federal income tax purposes the same as a repurchase or redemption
of shares, on which the shareholder may realize a capital gain or loss. However,
the ability to deduct capital losses on an exchange may be limited in situations
where there is an exchange of shares within ninety days after the shares are
purchased. The Exchange Privilege is only available in states where an exchange
may legally be made.
    
 
    If DWR or other Selected Broker-Dealer is the current dealer of record and
its account numbers are part of the account information, shareholders may
initiate an exchange of shares of the Fund for shares of any of the Dean Witter
Funds (for which the Exchange Privilege is available) pursuant to this Exchange
Privilege by contacting their account executive (no Exchange Privilege
Authorization Form is required). Other shareholders (and those shareholders who
are clients of DWR or another Selected Broker-Dealer but who wish to make
exchanges directly by writing or telephoning the Transfer Agent) must complete
and forward to the Transfer Agent an Exchange Privilege Authorization Form,
copies of which may be obtained from the Transfer Agent, to initiate an
exchange. If the Authorization Form is used, exchanges may be made in writing or
by contacting the Transfer Agent at (800) 869-NEWS (toll-free). The Fund will
employ reasonable procedures to confirm that exchange instructions communicated
over the telephone are genuine. Such procedures may include requiring various
forms of personal identification such as name, mailing address, social security
or other tax identification number and DWR or other Selected Broker-Dealer
account number (if any). Telephone instructions may also be recorded. If such
procedures are not employed, the Fund may be
 
                                       28
<PAGE>
liable for any losses due to unauthorized or fraudulent instructions.
 
    Telephone exchange instructions will be accepted if received by the Transfer
Agent between 9:00 a.m. and 4:00 p.m., New York time, on any day the New York
Stock Exchange is open. Any shareholder wishing to make an exchange who has
previously filed an Exchange Privilege Authorization Form and who is unable to
reach the Fund by telephone should contact his or her DWR or another Selected
Broker-Dealer account executive, if appropriate, or make a written exchange
request. Shareholders are advised that during periods of drastic economic or
market changes, it is possible that the telephone exchange procedures may be
difficult to implement, although this has not been the case with the Dean Witter
Funds in the past.
 
    Shareholders should contact their DWR or other Selected Broker-Dealer
account executive or the Transfer Agent for further information about the
Exchange Privilege.
 
REDEMPTIONS AND REPURCHASES
- --------------------------------------------------------------------------------
 
   
    REDEMPTION.  Shares of each Class of the Fund can be redeemed for cash at
any time at the net asset value per share next determined; less the amount of
any applicable CDSC in the case of Class A, Class B or Class C shares (see
"Purchase of Fund Shares"). If shares are held in a shareholder's account
without a share certificate, a written request for redemption sent to the Fund's
Transfer Agent at P.O. Box 983, Jersey City, NJ 07303 is required. If
certificates are held by the shareholder(s), the shares may be redeemed by
surrendering the certificate(s) with a written request for redemption, along
with any additional information required by the Transfer Agent.
    
 
    REPURCHASE.  DWR and other Selected Broker-Dealers are authorized to
repurchase shares represented by a share certificate which is delivered to any
of their offices. Shares held in a shareholder's account without a share
certificate may also be repurchased by DWR and other Selected Broker-Dealers
upon the telephonic or telegraphic request of the shareholder. The repurchase
price is the net asset value next computed (see "Purchase of Fund Shares") after
such repurchase order is received by DWR or other Selected Broker-Dealer,
reduced by any applicable CDSC.
 
   
    The CDSC, if any, will be the only fee imposed upon repurchase by the Fund
or the Distributor. The offer by DWR and other Selected Broker-Dealers to
repurchase shares may be suspended without notice by them at any time. In that
event, shareholders may redeem their shares through the Fund's Transfer Agent as
set forth above under "Redemption."
    
 
    PAYMENT FOR SHARES REDEEMED OR REPURCHASED.  Payment for shares presented
for repurchase or redemption will be made by check within seven days after
receipt by the Transfer Agent of the certificate and/or written request in good
order. Such payment may be postponed or the right of redemption suspended under
unusual circumstances, e.g., when normal trading is not taking place on the New
York Stock Exchange. If the shares to be redeemed have recently been purchased
by check, payment of the redemption proceeds may be delayed for the minimum time
needed to verify that the check used for investment has been honored (not more
than fifteen days from the time of receipt of the check by the Transfer Agent).
Shareholders maintaining margin accounts with DWR or another Selected
Broker-Dealer are referred to their account executives regarding restrictions on
redemption of shares of the Fund pledged in the margin account.
 
   
    REINSTATEMENT PRIVILEGE.  A shareholder who has had his or her shares
redeemed or repurchased and has not previously exercised this reinstatement
privilege may, within 35 days after the date of the redemption or repurchase,
reinstate any portion or all of the proceeds of such redemption or
    
repur-
 
                                       29
<PAGE>
   
chase in shares of the Fund in the same Class from which such shares were
redeemed or repurchased, at the net asset value next determined after a
reinstatement request, together with the proceeds, is received by the Transfer
Agent and receive a pro rata credit for any CDSC paid in connection with such
redemption or repurchase.
    
 
    INVOLUNTARY REDEMPTION.  The Fund reserves the right, on sixty days' notice,
to redeem, at their net asset value, the shares of any shareholder (other than
shares held in an Individual Retirement Account or Custodial Account under
Section 403(b)(7) of the Internal Revenue Code) whose shares, due to redemptions
by the shareholder,
 
have a value of less than $100 or such lesser amount as may be fixed by the
Fund's Trustees or, in the case of an account opened through EasyInvest, if
after twelve months the Shareholder has invested less than $1,000 in the
account. However, before the Fund redeems such shares and sends the proceeds to
the shareholder, it will notify the shareholder that the value of the shares is
less than the applicable amount and allow him or her sixty days to make an
additional investment in an amount which will increase the value of his or her
account to at least the applicable amount or more before the redemption is
processed. No CDSC will be imposed on any involuntary redemption.
 
DIVIDENDS, DISTRIBUTIONS AND TAXES
- --------------------------------------------------------------------------------
 
   
    DIVIDENDS AND DISTRIBUTIONS.  The Fund declares dividends separately for
each Class of shares and intends to pay quarterly income dividends and to
distribute net short-term and net long-term gains, if any, at least once per
year. The Fund may, however, determine either to distribute or to retain all or
part of any long-term gains in any year for reinvestment.
    
 
   
    All dividends and capital gains distributions will be paid in additional
shares of the same Class and automatically credited to the shareholder's account
without issuance of a share certificate unless the shareholder requests in
writing that all dividends and/or distributions be paid in cash. Shares acquired
by dividend and distribution reinvestments will not be subject to any front-end
sales charge or CDSC. Class B shares acquired through dividend and distribution
reinvestments will become eligible for conversion to Class A shares on a pro
rata basis. Distributions paid on Class A and Class D shares will be higher than
for Class B and Class C shares because distribution fees paid by Class B and
Class C shares are higher. (See "Shareholder Services--Automatic Investment of
Dividends and Distributions".)
    
 
   
    TAXES.  Because the Fund intends to distribute substantially all of its net
investment income and net capital gains to shareholders and otherwise remain
qualified as a regulated investment company under Subchapter M of the Internal
Revenue Code, it is not expected that the Fund will be required to pay any
federal income tax on such income and capital gains. Shareholders who are
required to pay taxes on their income will normally have to pay federal income
taxes, and any state income taxes, on the dividends and distributions they
receive from the Fund. Such dividends and distributions, to the extent they are
derived from net investment income or net short-term capital gains, are taxable
to the shareholder as ordinary dividend income regardless of whether the
shareholder receives such payments in additional shares or in cash. Any
dividends declared in the last quarter of any calendar year which are paid in
the following year prior to February 1 will be deemed, for tax purposes, to have
been received by the shareholder in the prior year.
    
 
    Gains or losses on the Fund's transactions in listed non-equity options,
futures and options on futures generally are treated as 60% long-term and 40%
short-term. When the Fund engages in options and futures transactions, various
tax regulations applicable to the Fund may have the effect of causing the Fund
to recognize a gain or loss for tax purposes before that gain or loss is
realized, or to defer recognition of a realized loss for tax purposes.
 
                                       30
<PAGE>
Recognition, for tax purposes, of an unrealized loss may result in a lesser
amount of the Fund's realized gains being available for annual distribution.
 
    With respect to the Fund's investments in zero coupon and payment-in-kind
bonds, the Fund accrues income prior to any actual cash payments by their
issuers. In order to continue to comply with Subchapter M of the Code and remain
able to forego payment of Federal income tax on its income and capital gains,
the Fund must distribute all of its net investment income, including income
accrued from zero coupon and payment-in-kind bonds. As such, the Fund may be
required to dispose of some of its portfolio securities under disadvantageous
circumstances to generate the cash required for distribution.
 
    One of the requirements for the Fund to remain qualified as a regulated
investment company is that less than 30% of the Fund's gross income be derived
from gains from the sale or other disposition of securities held for less than
three months. Accordingly, the Fund may be restricted in the writing of options
on securities held for less than three months, in the writing of options which
expire in less than three months, and in effecting closing transactions with
respect to call or put options which have been written or purchased less than
three months prior to such transactions. The Fund may also be restricted in its
ability to engage in transactions involving futures contracts.
 
   
    The Fund may at times make payments from sources other than income or net
capital gains. Payments from such sources would, in effect, represent a return
of a portion of each shareholder's investment. All, or a portion, of such
payments would not be taxable to shareholders.
    
 
    After the end of the calendar year, shareholders will receive full
information on their dividends and capital gains distributions for tax purposes.
To avoid being subject to a 31% federal backup withholding tax on taxable
dividends, capital gains distributions and the proceeds of redemptions and
repurchases, shareholders' taxpayer identification numbers must be furnished and
certified as to their accuracy.
 
    Distributions of net long-term capital gains, if any, are taxable to
shareholders as long-term capital gains regardless of how long a shareholder has
held the Fund's shares and regardless of whether the distribution is received in
additional shares or in cash. Capital gains distributions are not eligible for
the dividends received deduction.
 
    Shareholders should consult their tax advisers as to the applicability of
the foregoing to their current situation.
 
PERFORMANCE INFORMATION
- --------------------------------------------------------------------------------
 
   
    From time to time the Fund may quote its "yield" and/or its "total return"
in advertisements and sales literature. These figures are computed separately
for Class A, Class B, Class C and Class D shares. Both the yield and the total
return of the Fund are based on historical earnings and are not intended to
indicate future performance. The yield of each Class of the Fund is computed by
dividing the Class's net investment income over a 30-day period by an average
value (using the average number of shares entitled to receive dividends and the
maximum offering price per share at the end of the period), all in accordance
with applicable regulatory
    
 
   
requirements. Such amount is compounded for six months and then annualized for a
twelve-month period to derive the Fund's yield for each Class.
    
 
   
    The "average annual total return" of the Fund refers to a figure reflecting
the average annualized percentage increase (or decrease) in the value of an
initial investment in a Class of the Fund of $1,000 over periods of one, five
and ten years, as well as over the life of the Fund. Average annual total return
reflects all income earned by the Fund, any appreciation or depreciation of the
Fund's assets, all expenses incurred by the applicable Class and all sales
charges incurred by shareholders, for the
    
 
                                       31
<PAGE>
stated periods. It also assumes reinvestment of all dividends and distributions
paid by the Fund.
 
   
    In addition to the foregoing, the Fund may advertise its total return for
each Class over different periods of time by means of aggregate, average,
year-by-year or other types of total return figures. Such calculations may or
may not reflect the deduction of any sales charge which, if reflected, would
    
 
   
reduce the performance quoted. The Fund may also advertise the growth of
hypothetical investments of $10,000, $50,000 and $100,000 in each Class of
shares of the Fund. The Fund from time to time may also advertise its
performance relative to certain performance rankings and indices compiled by
independent organizations (such as mutual fund performance rankings of Lipper
Analytical Services, Inc.).
    
 
ADDITIONAL INFORMATION
- --------------------------------------------------------------------------------
 
   
    VOTING RIGHTS.  All shares of beneficial interest of the Fund are of $0.01
par value and are equal as to earnings, assets and voting privileges except that
each Class will have exclusive voting privileges with respect to matters
relating to distribution expenses borne solely by such Class or any other matter
in which the interests of one Class differ from the interests of any other
Class. In addition, Class B shareholders will have the right to vote on any
proposed material increase in Class A's expenses, if such proposal is submitted
separately to Class A shareholders. Also, as discussed herein, Class A, Class B
and Class C bear the expenses related to the distribution of their respective
shares.
    
 
    The Fund is not required to hold Annual Meetings of Shareholders and, in
ordinary circumstances, the Fund does not intend to hold such meetings. The
Trustees may call Special Meetings of Shareholders for action by shareholder
vote as may be required by the Act or the Declaration of Trust. Under certain
circumstances the Trustees may be removed by action of the Trustees or by the
Shareholders.
 
    Under Massachusetts law, shareholders of a business trust may, under certain
circumstances, be held personally liable as partners for the obligations of the
Fund. However, the Declaration of Trust contains an express disclaimer of
shareholder liability for acts or obligations of the Fund, requires that Fund
obligations include such disclaimer, and provides for indemnification and
reimbursement of expenses out of the Fund's property for 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
limited to circumstances in which the Fund itself would be unable to meet its
obligations. Given the above limitations on shareholder personal liability and
the nature of the Fund's assets and operations, the possibility of the Fund's
being unable to meet its obligations is remote and, thus, in the opinion of
Massachusetts counsel to the Fund, the risk to Fund shareholders of personal
liability is remote.
 
    CODE OF ETHICS.  Directors, officers and employees of InterCapital, Dean
Witter Services Company Inc. and the Distributor are subject to a strict Code of
Ethics adopted by those companies. The Code of Ethics is intended to ensure that
the interests of shareholders and other clients are placed ahead of any personal
interest, that no undue personal benefit is obtained from person's employment
activities and that actual and potential conflicts of interest are avoided. To
achieve these goals and comply with regulatory requirements, the Code of Ethics
requires, among other things, that personal securities transactions by employees
of the companies be subject to an advance clearance process to monitor that no
investment company managed or advised by InterCapital ("Dean Witter Fund") is
engaged at the same time in a purchase or sale of the same security. The Code of
Ethics bans the purchase of securities in an initial public offering, and also
prohibits engaging in futures and options transactions and profiting on
short-term trading (that is, a purchase within sixty days of a sale
 
                                       32
<PAGE>
or a sale within sixty days of a purchase) of a security. In addition,
investment personnel may not purchase or sell a security for their personal
account within thirty days before or after any transaction in any Dean Witter
Fund managed by them. Any violations of the Code of Ethics are subject to
sanctions, including reprimand, demotion or suspension or termination of
employment. The Code of Ethics comports with regulatory requirements and the
recommendations in the 1994 report by the Investment Company Institute Advisory
Group on Personal Investing.
 
   
    MASTER/FEEDER CONVERSION.  The Fund reserves the right to seek to achieve
its investment objective by investing all of its investable assets in a
diversified, open-end management investment company having the same investment
objective and policies and substantially the same investment restrictions as
those applicable to the Fund.
    
 
    SHAREHOLDER INQUIRIES.  All inquiries regarding the Fund should be directed
to the Fund at the telephone numbers or address set forth on the front cover of
this Prospectus.
 
                                       33
<PAGE>
APPENDIX
- --------------------------------------------------------------------------------
 
RATINGS OF INVESTMENTS
MOODY'S INVESTORS SERVICE INC. ("MOODY'S")
 
                                  BOND RATINGS
 
<TABLE>
<S>        <C>
Aaa        Bonds which 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 which are rated Aa are judged to be of 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 which make the long-term risks appear somewhat larger than in
           Aaa securities.
A          Bonds which 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 which suggest a
           susceptibility to impairment sometime in the future.
Baa        Bonds which 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.
           Bonds rated Aaa, Aa, A and Baa are considered investment grade bonds.
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 therefore 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 desirable investments. 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 present 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.
</TABLE>
 
    CONDITIONAL RATING:  Municipal bonds for which the security depends upon the
completion of some act or the fulfillment of some condition are rated
conditionally. These are bonds secured by (a) earnings of projects under
construction, (b) earnings of projects unseasoned in operation experience, (c)
rentals which begin
 
                                       34
<PAGE>
when facilities are completed, or (d) payments to which some other limiting
condition attaches. Parenthetical rating denotes probable credit stature upon
completion of construction or elimination of basis of condition.
 
    RATING REFINEMENTS:  Moody's may apply numerical modifiers, 1, 2 and 3 in
each generic rating classification from Aa through B in its corporate and
municipal bond rating system. The modifier 1 indicates that the security ranks
in the higher end of its generic rating category; the modifier 2 indicates a
mid-range ranking; and a modifier 3 indicates that the issue ranks in the lower
end of its generic rating category.
 
                            COMMERCIAL PAPER RATINGS
 
    Moody's Commercial Paper ratings are opinions of the ability to repay
punctually promissory obligations not having an original maturity in excess of
nine months. Moody's employs the following three designations, all judged to be
investment grade, to indicate the relative repayment capacity of rated issuers:
Prime-1, Prime-2, Prime-3.
 
    Issuers rated Prime-1 have a superior capacity for repayment of short-term
promissory obligations. Issuers rated Prime-2 have a strong capacity for
repayment of short-term promissory obligations; and Issuers rated Prime-3 have
an acceptable capacity for repayment of short-term promissory obligations.
Issuers rated Not Prime do not fall within any of the Prime rating categories.
 
STANDARD & POOR'S CORPORATION ("STANDARD & POOR'S")
 
                                  BOND RATINGS
 
    A Standard & Poor's bond rating is a current assessment of the
creditworthiness of an obligor with respect to a specific obligation. This
assessment may take into consideration obligors such as guarantors, insurers, or
lessees.
 
    The ratings are based on current information furnished by the issuer or
obtained by Standard & Poor's from other sources it considers reliable. The
ratings are based, in varying degrees, on the following considerations: (1)
likelihood of default-capacity and willingness of the obligor as to the timely
payment of interest and repayment of principal in accordance with the terms of
the obligation; (2) nature of and provisions of the obligation; and (3)
protection afforded by, and relative position of, the obligation in the event of
bankruptcy, reorganization or other arrangement under the laws of bankruptcy and
other laws affecting creditors' rights.
 
    Standard & Poor's does not perform an audit in connection with any rating
and may, on occasion, rely on unaudited financial information. The ratings may
be changed, suspended or withdrawn as a result of changes in, or unavailability
of, such information, or for other reasons.
 
<TABLE>
<S>        <C>
AAA        Debt rated AAA has the highest rating assigned by Standard & Poor's. Capacity to pay
           interest and repay principal is extremely strong.
AA         Debt rated AA has a very strong capacity to pay interest and repay principal and differs
           from the highest-rated issues only in small degree.
A          Debt rated A has 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 debt in higher-rated categories.
BBB        Debt rated BBB is regarded as having an adequate capacity to pay interest and repay
           principal. Whereas it normally exhibits adequate protection parameters, adverse economic
           conditions or changing circumstances are more likely to lead to a weakened capacity to
           pay interest and repay principal for debt in this category than for debt in higher-rated
           categories.
           Bonds rated AAA, AA, A and BBB are considered investment grade bonds.
</TABLE>
 
                                       35
<PAGE>
<TABLE>
<S>        <C>
BB         Debt rated BB has less near-term vulnerability to default than other speculative grade
           debt. However, it faces major ongoing uncertainties or exposure to adverse business,
           financial or economic conditions which could lead to inadequate capacity to meet timely
           interest and principal payment.
B          Debt rated B has a greater vulnerability to default but presently has the capacity to
           meet interest payments and principal repayments. Adverse business, financial or economic
           conditions would likely impair capacity or willingness to pay interest and repay
           principal.
CCC        Debt rated CCC has a current identifiable vulnerability to default, and is dependent upon
           favorable business, financial and economic conditions to meet timely payments of interest
           and repayments of principal. In the event of adverse business, financial or economic
           conditions, it is not likely to have the capacity to pay interest and repay principal.
CC         The rating CC is typically applied to debt subordinated to senior debt which is assigned
           an actual or implied CCC rating.
C          The rating C is typically applied to debt subordinated to senior debt which is assigned
           an actual or implied CCC- debt rating.
CI         The rating CI is reserved for income bonds on which no interest is being paid.
NR         Indicates that no rating has been requested, that there is insufficient information on
           which to base a rating or that Standard & Poor's does not rate a particular type of
           obligation as a matter of policy.
           Bonds rated BB, B, CCC, CC and C are regarded as having predominantly speculative
           characteristics with respect to capacity to pay interest and repay principal. BB
           indicates the least degree of speculation and C the highest degree of speculation. While
           such debt will likely have some quality and protective characteristics, these are
           outweighed by large uncertainties or major risk exposures to adverse conditions.
           Plus (+) or minus (-): The ratings from AA to CCC may be modified by the addition of a
           plus or minus sign to show relative standing within the major ratings categories.
           In the case of municipal bonds, the foregoing ratings are sometimes followed by a "p"
           which indicates that the rating is provisional. A provisional rating assumes the
           successful completion of the project being financed by the bonds being rated and
           indicates that payment of debt service requirements is largely or entirely dependent upon
           the successful and timely completion of the project. This rating, however, while
           addressing credit quality subsequent to completion of the project, makes no comment on
           the likelihood or risk of default upon failure of such completion.
</TABLE>
 
                                       36
<PAGE>
                            COMMERCIAL PAPER RATINGS
 
    Standard and Poor's commercial paper rating is a current assessment of the
likelihood of timely payment of debt having an original maturity of no more than
365 days. The commercial paper rating is not a recommendation to purchase or
sell a security. The ratings are based upon current information furnished by the
issuer or obtained by S&P from other sources it considers reliable. The ratings
may be changed, suspended, or withdrawn as a result of changes in or
unavailability of such information. Ratings are graded into group categories,
ranging from "A" for the highest quality obligations to "D" for the lowest.
Ratings are applicable to both taxable and tax-exempt commercial paper. The
categories are as follows:
 
    Issues assigned A ratings are regarded as having the greatest capacity for
timely payment. Issues in this category are further refined with the designation
1, 2 and 3 to indicate the relative degree of safety.
 
<TABLE>
<S>        <C>
A-1        indicates that the degree of safety regarding timely payment is very strong.
A-2        indicates capacity for timely payment on issues with this designation is strong. However,
           the relative degree of safety is not as overwhelming as for issues designated "A-1".
A-3        indicates a satisfactory capacity for timely payment. Obligations carrying this
           designation are, however, somewhat more vulnerable to the adverse effects of changes in
           circumstances than obligations carrying the higher designations.
</TABLE>
 
                                       37
<PAGE>
                        THE DEAN WITTER FAMILY OF FUNDS
 
   
MONEY MARKET FUNDS                       DEAN WITTER RETIREMENT SERIES
Dean Witter Liquid Asset Fund Inc.       Liquid Asset Series
Dean Witter Tax-Free Daily Income Trust  U.S. Government Money Market Series
Dean Witter U.S. Government Money        U.S. Government Securities Series
Market Trust                             Intermediate Income Securities Series
Dean Witter New York Municipal Money     American Value Series
Market Trust                             Capital Growth Series
Dean Witter California Tax-Free Daily    Dividend Growth Series
Income Trust                             Strategist Series
                                         Utilities Series
EQUITY FUNDS                             Value-Added Market Series
Dean Witter American Value Fund          Global Equity Series
Dean Witter Natural Resource
Development Securities Inc.              ASSET ALLOCATION FUNDS
Dean Witter Dividend Growth Securities   Dean Witter Strategist Fund
Inc.                                     Dean Witter Global Asset Allocation
Dean Witter Developing Growth            Fund
Securities Trust
Dean Witter World Wide Investment Trust  ACTIVE ASSETS ACCOUNT PROGRAM
Dean Witter Value-Added Market Series    Active Assets Money Trust
Dean Witter Utilities Fund               Active Assets Tax-Free Trust
Dean Witter Capital Growth Securities    Active Assets California Tax-Free Trust
Dean Witter European Growth Fund Inc.    Active Assets Government Securities
Dean Witter Pacific Growth Fund Inc.     Trust
Dean Witter Precious Metals and
Minerals Trust
Dean Witter Health Sciences Trust
Dean Witter Global Dividend Growth
Securities
Dean Witter Global Utilities Fund
Dean Witter International SmallCap Fund
Dean Witter Mid-Cap Growth Fund
Dean Witter Balanced Growth Fund
Dean Witter Capital Appreciation Fund
Dean Witter Information Fund
Dean Witter Japan Fund
Dean Witter Income Builder Fund
Dean Witter Special Value Fund
Dean Witter Financial Services Trust
Dean Witter Market Leader Trust
FIXED-INCOME FUNDS
Dean Witter High Yield Securities Inc.
Dean Witter Tax-Exempt Securities Trust
Dean Witter U.S. Government Securities
Trust
Dean Witter Intermediate Term U.S.
Treasury Trust
Dean Witter Federal Securities Trust
Dean Witter California Tax-Free Income
Fund
Dean Witter Convertible Securities
Trust
Dean Witter New York Tax-Free Income
Fund
Dean Witter World Wide Income Trust
Dean Witter Intermediate Income
Securities
Dean Witter Global Short-Term Income
Fund Inc.
Dean Witter Multi-State Municipal
Series Trust
Dean Witter Short-Term U.S. Treasury
Trust
Dean Witter Diversified Income Trust
Dean Witter Limited Term Municipal
Trust
Dean Witter Short-Term Bond Fund
Dean Witter National Municipal Trust
Dean Witter High Income Securities
Dean Witter Balanced Income Fund
Dean Witter Hawaii Municipal Trust
    
<PAGE>
 
Dean Witter                         DEAN WITTER
Convertible Securities Trust        CONVERTIBLE
Two World Trade Center              SECURITIES
New York, New York 10048            TRUST
 
   
TRUSTEES
Michael Bozic
Charles A. Fiumefreddo
Edwin J. Garn
John R. Haire
Dr. Manuel H. Johnson
Michael E. Nugent
Philip J. Purcell
John L. Schroeder
 
OFFICERS
Charles A. Fiumefreddo
Chairman and Chief Executive
Officer
 
Barry Fink
Vice President, Secretary and
General Counsel
 
Michael G. Knox                                   [LOGO]
Vice President
 
Thomas F. Caloia
Treasurer
 
CUSTODIAN
The Bank of New York
90 Washington Street
New York, New York 10286
 
TRANSFER AGENT AND DIVIDEND
DISBURSING AGENT
Dean Witter Trust Company
Harborside Financial Center
Plaza Two
Jersey City, New Jersey 07311
 
INDEPENDENT ACCOUNTANTS
Price Waterhouse LLP
1177 Avenue of the Americas
New York, New York 10036
 
INVESTMENT MANAGER
Dean Witter InterCapital Inc.
                                            PROSPECTUS -- JULY 28, 1997
 
    
<PAGE>
   
STATEMENT OF ADDITIONAL INFORMATION
JULY 28, 1997
    
 
- --------------------------------------------------------------------------------
 
DEAN WITTER
CONVERTIBLE
SECURITIES TRUST
 
    Dean Witter Convertible Securities Trust (the "Fund") is an open-end
diversified management investment company whose investment objective is to seek
a high level of total return on its assets through a combination of current
income and capital appreciation. It seeks to achieve its investment objective by
investing principally in "convertible securities," that is, bonds, notes,
debentures, preferred stocks and other securities which are convertible into
common stocks. (See "Investment Practices and Policies".)
 
   
    A Prospectus for the Fund dated July 28, 1997, which provides the basic
information you should know before investing in the Fund, may be obtained
without charge from the Fund at the address or telephone numbers listed below or
from the Fund's Distributor, Dean Witter Distributors Inc., or from Dean Witter
Reynolds Inc. at any of its branch offices. This Statement of Additional
Information is not a Prospectus. It contains information in addition to and more
detailed than that set forth in the Prospectus. It is intended to provide
additional information regarding the activities and operations of the Fund, and
should be read in conjunction with the Prospectus.
    
 
Dean Witter
Convertible Securities Trust
Two World Trade Center
New York, New York 10048
(212) 392-2550 or
(800) 869-NEWS (toll-free)
<PAGE>
TABLE OF CONTENTS
- --------------------------------------------------------------------------------
 
   
<TABLE>
<S>                                                                                      <C>
The Fund and its Management............................................................          3
 
Trustees and Officers..................................................................          6
 
Investment Practices and Policies......................................................         12
 
Investment Restrictions................................................................         23
 
Portfolio Transactions and Brokerage...................................................         24
 
The Distributor........................................................................         25
 
Purchase of Fund Shares................................................................         30
 
Shareholder Services...................................................................         33
 
Redemptions and Repurchases............................................................         37
 
Dividends, Distributions and Taxes.....................................................         39
 
Performance Information................................................................         40
 
Description of Shares of the Fund......................................................         41
 
Custodian and Transfer Agent...........................................................         42
 
Independent Accountants................................................................         42
 
Reports to Shareholders................................................................         42
 
Legal Counsel..........................................................................         42
 
Experts................................................................................         42
 
Registration Statement.................................................................         42
 
Report of Independent Accountants......................................................         43
 
Financial Statements -- September 30, 1996.............................................         53
 
Financial Statements -- March 31, 1997 (unaudited).....................................         69
</TABLE>
    
 
                                       2
<PAGE>
THE FUND AND ITS MANAGEMENT
- --------------------------------------------------------------------------------
 
THE FUND
 
    The Fund is a Trust of the type commonly known as a "Massachusetts business
trust" and was organized under the laws of the Commonwealth of Massachusetts on
May 21, 1985.
 
THE INVESTMENT MANAGER
 
   
    Dean Witter InterCapital Inc. (the "Investment Manager" or "InterCapital"),
a Delaware corporation, whose address is Two World Trade Center, New York, New
York 10048, is the Fund's Investment Manager. InterCapital is a wholly-owned
subsidiary of Morgan Stanley, Dean Witter, Discover & Co. ("MSDWD"), a Delaware
corporation. In an internal reorganization which took place in January, 1993,
InterCapital assumed the investment advisory, administrative and management
activities previously performed by the InterCapital Division of Dean Witter
Reynolds Inc. ("DWR"), a broker-dealer affiliate of InterCapital. (As
hereinafter used in this Statement of Additional Information, the terms
"InterCapital" and "Investment Manager" refer to DWR's InterCapital Division
prior to the internal reorganization and to Dean Witter InterCapital Inc.
thereafter.) The daily management of the Fund and research relating to the
Fund's portfolio are conducted by or under the direction of officers of the Fund
and of the Investment Manager, subject to review by the Fund's Board of
Trustees. In addition, Trustees of the Fund provide guidance on economic factors
and interest rate trends. Information as to these Trustees and Officers is
contained under the caption "Trustees and Officers."
    
 
   
    InterCapital is also the investment manager or investment adviser of the
following management investment companies: Active Assets Money Trust, Active
Assets Tax-Free Trust, Active Assets California Tax-Free Trust, Active Assets
Government Securities Trust, InterCapital Income Securities Inc., InterCapital
Insured Municipal Bond Trust, InterCapital Insured Municipal Trust, InterCapital
Insured Municipal Income Trust, InterCapital Insured Municipal Securities,
InterCapital California Insured Municipal Income Trust, InterCapital Insured
California Municipal Securities, InterCapital Quality Municipal Investment
Trust, InterCapital Quality Municipal Income Trust, InterCapital Quality
Municipal Securities, InterCapital California Quality Municipal Securities,
InterCapital New York Quality Municipal Securities, High Income Advantage Trust,
High Income Advantage Trust II, High Income Advantage Trust III, Dean Witter
Government Income Trust, Dean Witter High Yield Securities Inc., Dean Witter
Tax-Free Daily Income Trust, Dean Witter Tax-Exempt Securities Trust, Dean
Witter Dividend Growth Securities Inc., Dean Witter Natural Resource Development
Securities Inc., Dean Witter American Value Fund, Dean Witter Developing Growth
Securities Trust, Dean Witter U.S. Government Money Market Trust, Dean Witter
Variable Investment Series, Dean Witter World Wide Investment Trust, Dean Witter
Select Municipal Reinvestment Fund, Dean Witter U.S. Government Securities
Trust, Dean Witter World Wide Income Trust, Dean Witter California Tax-Free
Income Fund, Dean Witter New York Tax-Free Income Fund, Dean Witter Convertible
Securities Trust, Dean Witter Federal Securities Trust, Dean Witter Value-Added
Market Series, Dean Witter Utilities Fund, Dean Witter California Tax-Free Daily
Income Trust, Dean Witter Strategist Fund, Dean Witter Intermediate Income
Securites, Dean Witter Capital Growth Securities, Dean Witter Precious Metals
and Minerals Trust, Dean Witter New York Municipal Money Market Trust, Dean
Witter European Growth Fund Inc., Dean Witter Global Short-Term Income Fund
Inc., Dean Witter Pacific Growth Fund Inc., Dean Witter Multi-State Municipal
Series Trust, Dean Witter Short-Term U.S. Treasury Trust, Dean Witter
Diversified Income Trust, Dean Witter Health Sciences Trust, Dean Witter
Retirement Series, Dean Witter Global Dividend Growth Securities, Dean Witter
Limited Term Municipal Trust, Dean Witter Short-Term Bond Fund, Dean Witter
Global Utilities Fund, Dean Witter High Income Securities, Dean Witter
Information Fund, Dean Witter National Municipal Trust, Dean Witter
International SmallCap Fund, Dean Witter Mid-Cap Growth Fund, Dean Witter Select
Dimensions Investment Series, Dean Witter Balanced Income Fund, Dean Witter
Balanced Growth Fund, Dean Witter Hawaii Municipal Trust, Dean Witter Japan
Fund, Dean Witter Income Builder Fund, Dean Witter Special Value Fund, Dean
Witter Financial Services Trust, Dean Witter Market Leader Trust, Dean Witter
Capital Appreciation Fund, Dean Witter Intermediate Term U.S. Treasury Trust,
Municipal Income Trust, Municipal Income Trust II, Municipal Income Trust III,
Municipal Income Opportunities Trust, Municipal Income
    
 
                                       3
<PAGE>
Opportunities Trust II, Municipal Income Opportunities Trust III, Municipal
Premium Income Trust and Prime Income Trust. The foregoing investment companies,
together with the Fund, are collectively referred to as the Dean Witter Funds.
 
   
    In addition, Dean Witter Services Company Inc. ("DWSC"), a wholly-owned
subsidiary of InterCapital, serves as manager for the following investment
companies for which TCW Funds Management, Inc. is the investment adviser: TCW/DW
Core Equity Trust, TCW/DW North American Government Income Trust, TCW/DW Latin
American Growth Fund, TCW/DW Income and Growth Fund, TCW/DW Small Cap Growth
Fund, TCW/DW Balanced Fund, TCW/DW Total Return Trust, TCW/DW Mid-Cap Equity
Trust, TCW/DW Global Telecom Trust, TCW/DW Strategic Income Trust, TCW/DW
Emerging Markets Opportunities Trust, TCW/DW Term Trust 2000, TCW/DW Term Trust
2002 and TCW/DW Term Trust 2003 (the "TCW/DW Funds"). InterCapital also serves
as: (i) administrator of The BlackRock Strategic Term Trust Inc., a closed-end
investment company; and (ii) sub-administrator of MassMutual Participation
Investors and Templeton Global Governments Income Trust, closed-end investment
companies.
    
 
    Pursuant to an Investment Management Agreement (the "Agreement") with the
Investment Manager, the Fund has retained the Investment Manager to manage the
investment of the Fund's assets, including the placing of orders for the
purchase and sale of portfolio securities. The Investment Manager obtains and
evaluates such information and advice relating to the economy, securities
markets, and specific securities as it considers necessary or useful to
continuously manage the assets of the Fund in a manner consistent with its
investment objective and policies.
 
    Under the terms of the Agreement, in addition to managing the Fund's
investments, the Investment Manager maintains certain of the Fund's books and
records and furnishes, at its own expense, such office space, facilities,
equipment, clerical help, bookkeeping and certain legal services as the Fund may
reasonably require in the conduct of its business, including the preparation of
prospectuses, statements of additional information, proxy statements and reports
required to be filed with federal and state securities commissions (except
insofar as the participation or assistance of independent accountants and
attorneys is, in the opinion of the Investment Manager, necessary or desirable).
In addition, the Investment Manager pays the salaries of all personnel,
including officers of the Fund, who are employees of the Investment Manager. The
Investment Manager also bears the cost of telephone service, heat, light, power
and other utilities provided to the Fund.
 
    Effective December 31, 1993, pursuant to a Services Agreement between
InterCapital and DWSC, DWSC began to provide the administrative services to the
Fund which were previously performed directly by InterCapital. On April 17,
1995, DWSC was reorganized in the State of Delaware, necessitating the entry
into a new Services Agreement by InterCapital and DWSC on such date. The
foregoing internal reorganizations did not result in any change in the nature or
scope of the administrative services being provided to the Fund or any of the
fees being paid by the Fund for the overall services being performed under the
terms of the existing Agreement.
 
   
    Expenses not expressly assumed by the Investment Manager under the Agreement
or by the Distributor of the Fund's shares (see "The Distributor") will be paid
by the Fund. These expenses will be allocated among the four classes of shares
of the Fund (each, a "Class") pro rata based on the net assets of the Fund
attributable to each Class, except as described below. The expenses borne by the
Fund include, but are not limited to: expenses of the Plan of Distribution
pursuant to Rule 12b-1 (the "12b-1 fee") (see "The Distributor"), charges and
expenses of any registrar, custodian, stock transfer and dividend disbursing
agent; brokerage commissions; taxes; engraving and printing of share
certificates; registration costs of the Fund and its shares under federal and
state securities laws; the cost and expense of printing, including typesetting,
and distributing Prospectuses and Statements of Additional Information of the
Fund and supplements thereto to the Fund's shareholders; all expenses of
shareholders' and Trustees' meetings and of preparing, printing and mailing of
proxy statements and reports to shareholders; fees and travel expenses of
trustees or members of any advisory board or committee who are not employees of
the Investment Manager or any corporate affiliate of the Investment Manager; all
    
 
                                       4
<PAGE>
   
expenses incident to any dividend, withdrawal or redemption options; charges and
expenses of any outside service used for pricing of the Fund's shares; fees and
expenses of legal counsel, including counsel to the trustees who are not
interested persons of the Fund or of the Investment Manager (not including
compensation or expenses of attorneys who are employees of the Investment
Manager) and independent accountants; membership dues of industry associations;
interest on Fund borrowings; postage; insurance premiums on property or
personnel (including officers and trustees) of the Fund which inure to its
benefit; extraordinary expenses (including, but not limited to, legal claims and
liabilities and litigation costs and any indemnification relating thereto); and
all other costs of the Fund's operation. The 12b-1 fees relating to a particular
Class will be allocated directly to that Class. In addition, other expenses
associated with a particular Class (except advisory or custodial fees) may be
allocated directly to that Class, provided that such expenses are reasonably
identified as specifically attributable to that Class and the direct allocation
to that Class is approved by the Trustees.
    
 
    As full compensation for the services and facilities furnished to the Fund
and expenses of the Fund assumed by the Investment Manager, the Fund pays the
Investment Manager monthly compensation calculated daily by applying the
following annual rates to the Fund's daily net assets: 0.60% of the portion of
the daily net assets of the Fund not exceeding $750 million and 0.55% of the
portion of the daily net assets exceeding $750 million but not exceeding $1
billion; 0.50% of the portion of the daily net assets of the Fund exceeding $1
billion but not exceeding $1.5 billion; 0.475% of the portion of the Fund's
daily net assets exceeding $1.5 billion but not exceeding $2 billion; 0.45% of
the portion of the Fund's daily net assets exceeding $2 billion but not
exceeding $3 billion; and 0.425% of the portion of the Fund's daily net assets
exceeding $3 billion. Total compensation accrued to the Investment Manager for
the fiscal years ended September 30, 1994, 1995 and 1996 amounted to $1,201,442,
$1,074,494 and $1,234,262, respectively.
 
   
    The Agreement provides that in the absence of willful misfeasance, bad
faith, gross negligence or reckless disregard of its obligations thereunder, the
Investment Manager is not liable to the Fund or any of its investors for any act
or omission by the Investment Manager or for any losses sustained by the Fund or
its investors. The Agreement in no way restricts the Investment Manager from
acting as investment manager or adviser to others.
    
 
   
    The Agreement was initially approved by the Board of Trustees on February
21, 1997 and by the shareholders of the Fund at a Special Meeting of
Shareholders held on May 21, 1997. The Agreement is substantially identical to a
prior investment management agreement which was initially approved by the Board
of Trustees on October 30, 1992 and by the shareholders of the Fund at a Special
Meeting of Shareholders held on January 12, 1993. The Agreement took effect on
May 31, 1997 upon the consummation of the merger of Dean Witter, Discover & Co.
with Morgan Stanley Group Inc. The Agreement may be terminated at any time,
without penalty, on thirty days' notice by the Board of Trustees of the Fund, by
the holders of a majority, as defined in the Investment Company Act of 1940 (the
"Act"), of the outstanding shares of the Fund, or by the Investment Manager. The
Agreement will automatically terminate in the event of its assignment (as
defined in the Act).
    
 
   
    Under its terms, the Agreement has an initial term ending April 30, 1999 and
will remain in effect from year to year thereafter, provided continuance of the
Agreement is approved at least annually by the vote of the holders of a
majority, as defined in the Act, of the outstanding shares of the Fund, or by
the Board of Trustees of the Fund; provided that in either event such
continuance is approved annually by the vote of a majority of the Trustees of
the Fund who are not parties to the Agreement or "interested persons" (as
defined in the Act) of any such party (the "Independent Trustees"), which vote
must be cast in person at a meeting called for the purpose of voting on such
approval.
    
 
    The Fund has acknowledged that the name "Dean Witter" is a property right of
DWR. The Fund has agreed that DWR or its parent company may use or, at any time,
permit others to use, the name "Dean Witter." The Fund has also agreed that in
the event the Agreement is terminated, or if the affiliation between
InterCapital and its parent company is terminated, the Fund will eliminate the
name "Dean Witter" from its name if DWR or its parent company shall so request.
 
                                       5
<PAGE>
TRUSTEES AND OFFICERS
- --------------------------------------------------------------------------------
 
    The Trustees and Executive Officers of the Fund, their principal business
occupations during the last five years and their affiliations, if any, with
InterCapital and with the 83 Dean Witter Funds and the 14 TCW/DW Funds are shown
below.
 
   
<TABLE>
<CAPTION>
      NAME, AGE, POSITION WITH FUND AND ADDRESS                PRINCIPAL OCCUPATIONS DURING LAST FIVE YEARS
- ------------------------------------------------------  ----------------------------------------------------------
<S>                                                     <C>
Michael Bozic (56)                                      Chairman and Chief Executive Officer of Levitz Furniture
Trustee                                                 Corporation (since November 1995); Director or Trustee of
c/o Levitz Furniture Corporation                        the Dean Witter Funds; formerly President and Chief
6111 Broken Sound Parkway, N.W.                         Executive Officer of Hills Department Stores (May,
Boca Raton, Florida                                     1991-July, 1995); formerly variously Chairman, Chief
                                                        Executive Officer, President and Chief Operating Officer
                                                        (1987-1991) of the Sears Merchandise Group of Sears,
                                                        Roebuck and Co.; Director of Eaglemark Financial Services,
                                                        Inc., the United Negro College Fund and Weirton Steel Cor-
                                                        poration.
 
Charles A. Fiumefreddo* (64)                            Chairman, Chief Executive Officer and Director of
Chairman of the Board, President, Chief                 InterCapital, Dean Witter Distributors Inc. ("Distribu-
 Executive Officer and Trustee                          tors") and DWSC; Executive Vice President and Director of
Two World Trade Center                                  DWR; Chairman, Director or Trustee, President and Chief
New York, New York                                      Executive Officer of the Dean Witter Funds; Chairman,
                                                        Chief Executive Officer and Trustee of the TCW/DW Funds;
                                                        Chairman and Director of Dean Witter Trust Company
                                                        ("DWTC"); Director and/or officer of various MSDWD
                                                        subsidiaries; formerly Executive Vice President and
                                                        Director of Dean Witter Discover & Co. (until February,
                                                        1993).
 
Edwin J. Garn (64)                                      Director or Trustee of the Dean Witter Funds; formerly
Trustee                                                 United States Senator (R-Utah) (1974-1992) and Chairman,
c/o Huntsman Corporation                                Senate Banking Committee (1980-1986); formerly Mayor of
500 Huntsman Way                                        Salt Lake City, Utah (1972-1974); formerly Astronaut,
Salt Lake City, Utah                                    Space Shuttle Discovery (April 12-19, 1985); Vice
                                                        Chairman, Huntsman Corporation (since January, 1993);
                                                        Director of Franklin Quest (time management systems) and
                                                        John Alden Financial Corp. (health insurance); member of
                                                        the board of various civic and charitable organizations.
John R. Haire (72)                                      Chairman of the Audit Committee and Chairman of the
Trustee                                                 Committee of the Independent Directors or Trustees and
Two World Trade Center                                  Director or Trustee of the Dean Witter Funds; Chairman of
New York, New York                                      the Audit Committee and Chairman of the Committee of the
                                                        Independent Trustees and Trustee of the TCW/DW Funds;
                                                        formerly President, Council for Aid to Education
                                                        (1978-1989) and Chairman and Chief Executive Officer of
                                                        Anchor Corporation, an Investment Adviser (1964-1978);
                                                        Director of Washington National Corporation (insurance).
</TABLE>
    
 
                                       6
<PAGE>
   
<TABLE>
<CAPTION>
      NAME, AGE, POSITION WITH FUND AND ADDRESS                PRINCIPAL OCCUPATIONS DURING LAST FIVE YEARS
- ------------------------------------------------------  ----------------------------------------------------------
<S>                                                     <C>
Wayne E. Hedien** (63)                                  Retired, Director or Trustee of the Dean Witter Funds
Trustee                                                 (commencing on September 1, 1997); Director of The PMI
c/o Gordon Altman Butowsky                              Group, Inc. (private mortgage insurance); Trustee and Vice
 Weitzen Shalov & Wein                                  Chairman of The Field Museum of Natural History; formerly
Counsel to the Independent Trustees                     associated with the Allstate Companies (1966-1994), most
114 West 47th Street                                    recently as Chairman of The Allstate Corporation (March,
New York, New York                                      1993-December, 1994) and Chairman and Chief Executive
                                                        Officer of its wholly-owned subsidiary, Allstate Insurance
                                                        Company (July, 1989-December, 1994); director of various
                                                        other business and charitable organizations.
Dr. Manuel H. Johnson (48)                              Senior Partner, Johnson Smick International, Inc., a
Trustee                                                 consulting firm; Co-Chairman and a founder of the Group of
c/o Johnson Smick International, Inc.                   Seven Council (G7C), an international economic commission;
1133 Connecticut Avenue, N.W.                           Trustee of the TCW/DW Funds; Director of Greenwich Capital
Washington, D.C.                                        Markets Inc. (broker-dealer); Director of NASDAQ (since
                                                        June, 1995); Trustee of the Financial Accounting
                                                        Foundation (oversight organization for the Financial
                                                        Accounting Standards Board); formerly Vice Chairman of the
                                                        Board of Governors of the Federal Reserve System
                                                        (1986-1990) and Assistant Secretary of the U.S. Treasury
                                                        (1982-1986).
Michael E. Nugent (60)                                  General Partner, Triumph Capital, L.P., a private in-
Trustee                                                 vestment partnership; Director or Trustee of the Dean
c/o Triumph Capital, L.P.                               Witter Funds; Trustee of the TCW/DW Funds; formerly Vice
237 Park Avenue                                         President, Bankers Trust Company and BT Capital
New York, New York                                      Corporation (1984-1988); Director of various business
                                                        organizations.
Philip J. Purcell* (53)                                 Chairman of the Board of Directors and Chief Executive
Trustee                                                 Officer of MSDWD, DWR and Novus Credit Services Inc.;
1585 Broadway                                           Director of InterCapital, DWSC and Distributors; Director
New York, New York                                      or Trustee of the Dean Witter Funds; Director and/or
                                                        officer of various MSDWD subsidiaries.
 
John L. Schroeder (66)                                  Retired; Director or Trustee of the Dean Witter Funds;
Trustee                                                 Trustee of the TCW/DW Funds; Director of Citizens
c/o Gordon Altman Butowsky                              Utilities Company; formerly Executive Vice President and
  Weitzen Shalov & Wein                                 Chief Investment Officer of the Home Insurance Company
Counsel to the Independent Trustees                     (August, 1991-September, 1995) and Chairman and Chief
114 West 47th Street                                    Investment Officer of Axe-Houghton Management and the
New York, New York                                      Axe-Houghton Funds (1983-1991).
</TABLE>
    
 
                                       7
<PAGE>
   
<TABLE>
<CAPTION>
      NAME, AGE, POSITION WITH FUND AND ADDRESS                PRINCIPAL OCCUPATIONS DURING LAST FIVE YEARS
- ------------------------------------------------------  ----------------------------------------------------------
<S>                                                     <C>
Barry Fink (42)                                         Senior Vice President (since March, 1997) and Secretary
Vice President, Secretary                               and General Counsel (since February, 1997) of InterCapital
 and General Counsel                                    and DWSC; Senior Vice President (since March, 1997) and
Two World Trade Center                                  Assistant Secretary and Assistant General Counsel (since
New York, New York                                      February, 1997) of Distributors; Assistant Secretary of
                                                        DWR (since August, 1996); Vice President, Secretary and
                                                        General Counsel of the Dean Witter Funds and the TCW/DW
                                                        Funds (since February, 1997); previously First Vice
                                                        President (June, 1993-February, 1997), Vice President
                                                        (until June, 1993) and Assistant Secretary and Assistant
                                                        General Counsel of InterCapital and DWSC and Assistant
                                                        Secretary of the Dean Witter Funds and the TCW/DW Funds.
 
Michael G. Knox (31)                                    Vice President of InterCapital (since May, 1995); pre-
Vice President                                          viously, Senior Portfolio Manager of InterCapital (Au-
Two World Trade Center                                  gust, 1993-May, 1995); formerly a portfolio manager and
New York, New York                                      analyst with Eagle Asset Management, Inc. (February,
                                                        1991-August, 1993) and assistant portfolio manager and
                                                        analyst with Heritage Asset Management, Inc. (July,
                                                        1988-February, 1991).
 
Thomas F. Caloia (51)                                   First Vice President and Assistant Treasurer of Inter-
Treasurer                                               Capital and DWSC; Treasurer of the Dean Witter Funds and
Two World Trade Center                                  the TCW/DW Funds.
New York, New York
</TABLE>
    
 
- ---------
 *Denotes Trustees who are "interested persons" of the Fund, as defined in the
  Act.
   
**Mr.Hedien's term as Trustee will commence on September 1, 1997.
    
 
   
    In addition, Robert M. Scanlan, President and Chief Operating Officer of
InterCapital and DWSC, Executive Vice President of Distributors and DWTC and
Director of DWTC, Mitchell M. Merin, President and Chief Strategic Officer of
InterCapital and DWSC, Executive Vice President of Distributors and DWTC and
Director of DWTC, Executive Vice President and Director of DWR, Director of SPS
Transaction Services Inc. and various other MSDWD subsidiaries, Robert S.
Giambrone, Senior Vice President of InterCapital, DWSC, Distributors and DWTC
and Director of DWTC, Joseph J. McAlinden, Executive Vice President and Chief
Investment Officer of InterCapital and Director of DWTC, and Kevin Hurley, Paul
D. Vance and Ira N. Ross, Senior Vice Presidents of InterCapital, are Vice
Presidents of the Fund. Marilyn K. Cranney, First Vice President and Assistant
General Counsel of InterCapital and DWSC, LouAnne D. McInnis, Ruth Rossi and
Carsten Otto, Vice Presidents and Assistant General Counsels of InterCapital and
DWSC, and Frank Bruttomesso, a Staff Attorney with InterCapital, are Assistant
Secretaries of the Fund.
    
 
   
THE BOARD OF TRUSTEES, THE INDEPENDENT TRUSTEES, AND THE COMMITTEES
    
 
   
    The Board of Trustees currently consists of eight (8) trustees; as noted
above, Mr. Hedien's term will commence on September 1, 1997. These same
individuals also serve as directors or trustees for all of the Dean Witter
Funds, and are referred to in this section as Trustees. As of the date of this
Statement of Additional Information, there are a total of 83 Dean Witter Funds,
comprised of 126 portfolios. As of June 30, 1997, the Dean Witter Funds had
total net assets of approximately $87.9 billion and more than six million
shareholders.
    
 
   
    Six Trustees and Mr. Hedien (77% of the total number) have no affiliation or
business connection with InterCapital or any of its affiliated persons and do
not own any stock or other securities issued by
    
 
                                       8
<PAGE>
   
InterCapital's parent company, MSDWD. These are the "disinterested" or
"independent" Trustees. The other two Trustees (the "management Trustees") are
affiliated with InterCapital. Four of the six independent Trustees are also
Independent Trustees of the TCW/DW Funds.
    
 
   
    Law and regulation establish both general guidelines and specific duties for
the Independent Trustees. The Dean Witter Funds seek as Independent Trustees
individuals of distinction and experience in business and finance, government
service or academia; these are people whose advice and counsel are in demand by
others and for whom there is often competition. To accept a position on the
Funds' Boards, such individuals may reject other attractive assignments because
the Funds make substantial demands on their time. Indeed, by serving on the
Funds' Boards, certain Trustees who would otherwise be qualified and in demand
to serve on bank boards would be prohibited by law from doing so.
    
 
   
    All of the current Independent Trustees serve as members of the Audit
Committee and the Committee of the Independent Trustees. Three of them also
serve as members of the Derivatives Committee. During the calendar year ended
December 31, 1996, the three Committees held a combined total of sixteen
meetings. The Committees hold some meetings at InterCapital's offices and some
outside InterCapital. Management Trustees or officers do not attend these
meetings unless they are invited for purposes of furnishing information or
making a report.
    
 
   
    The Committee of the Independent Trustees is charged with recommending to
the full Board approval of management, advisory and administration contracts,
Rule 12b-1 plans and distribution and underwriting agreements; continually
reviewing Fund performance; checking on the pricing of portfolio securities,
brokerage commissions, transfer agent costs and performance, and trading among
Funds in the same complex; and approving fidelity bond and related insurance
coverage and allocations, as well as other matters that arise from time to time.
The Independent Trustees are required to select and nominate individuals to fill
any Independent Trustee vacancy on the Board of any Fund that has a Rule 12b-1
plan of distribution. Most of the Dean Witter Funds have such a plan.
    
 
   
    The Audit Committee is charged with recommending to the full Board the
engagement or discharge of the Fund's independent accountants; directing
investigations into matters within the scope of the independent accountants'
duties, including the power to retain outside specialists; reviewing with the
independent accountants the audit plan and results of the auditing engagement;
approving professional services provided by the independent accountants and
other accounting firms prior to the performance of such services; reviewing the
independence of the independent accountants; considering the range of audit and
non-audit fees; reviewing the adequacy of the Fund's system of internal
controls; and preparing and submitting Committee meeting minutes to the full
Board.
    
 
   
    Finally, the Board of each Fund has formed a Derivatives Committee to
establish parameters for and oversee the activities of the Fund with respect to
derivative investments, if any, made by the Fund.
    
 
   
DUTIES OF CHAIRMAN OF COMMITTEE OF THE INDEPENDENT TRUSTEES AND AUDIT COMMITTEE
    
 
   
    The Chairman of the Committee of the Independent Trustees and the Audit
Committee maintains an office at the Funds' headquarters in New York. He is
responsible for keeping abreast of regulatory and industry developments and the
Funds' operations and management. He screens and/or prepares written materials
and identifies critical issues for the Independent Trustees to consider,
develops agendas for Committee meetings, determines the type and amount of
information that the Committees will need to form a judgment on various issues,
and arranges to have that information furnished to Committee members. He also
arranges for the services of independent experts and consults with them in
advance of meetings to help refine reports and to focus on critical issues.
Members of the Committees believe that the person who serves as Chairman of both
Committees and guides their efforts is pivotal to the effective functioning of
the Committees.
    
 
   
    The Chairman of the Committees also maintains continuous contact with the
Funds' management, with independent counsel to the Independent Trustees and with
the Funds' independent auditors. He
    
 
                                       9
<PAGE>
   
arranges for a series of special meetings involving the annual review of
investment advisory, management and other operating contracts of the Funds and,
on behalf of the Committees, conducts negotiations with the Investment Manager
and other service providers. In effect, the Chairman of the Committees serves as
a combination of chief executive and support staff of the Independent Trustees.
    
 
   
    The Chairman of the Committee of the Independent Trustees and the Audit
Committee is not employed by any other organization and devotes his time
primarily to the services he performs as Committee Chairman and Independent
Trustee of the Dean Witter Funds and as an Independent Trustee and, since July
1, 1996, as Chairman of the Committee of the Independent Trustees and the Audit
Committee of the TCW/DW Funds. The current Committee Chairman has had more than
35 years experience as a senior executive in the investment company industry.
    
 
   
ADVANTAGES OF HAVING SAME INDIVIDUALS AS INDEPENDENT TRUSTEES FOR ALL DEAN
WITTER FUNDS
    
 
   
    The Independent Trustees and the Funds' management believe that having the
same Independent Trustees for each of the Dean Witter Funds avoids the
duplication of effort that would arise from having different groups of
individuals serving as Independent Trustees for each of the Funds or even of
sub-groups of Funds. They believe that having the same individuals serve as
Independent Trustees of all the Funds tends to increase their knowledge and
expertise regarding matters which affect the Fund complex generally and enhances
their ability to negotiate on behalf of each Fund with the Fund's service
providers. This arrangement also precludes the possibility of separate groups of
Independent Trustees arriving at conflicting decisions regarding operations and
management of the Funds and avoids the cost and confusion that would likely
ensue. Finally, having the same Independent Trustees serve on all Fund Boards
enhances the ability of each Fund to obtain, at modest cost to each separate
Fund, the services of Independent Trustees, and a Chairman of their Committees,
of the caliber, experience and business acumen of the individuals who serve as
Independent Trustees of the Dean Witter Funds.
    
 
COMPENSATION OF INDEPENDENT TRUSTEES
 
    The Fund pays each Independent Trustee an annual fee of $1,000 plus a per
meeting fee of $50 for meetings of the Board of Trustees or committees of the
Board of Trustees attended by the Trustee (the Fund pays the Chairman of the
Audit Committee an annual fee of $750 and pays the Chairman of the Committee of
the Independent Trustees an additional annual fee of $1,200). The Fund also
reimburses such Trustees for travel and other out-of-pocket expenses incurred by
them in connection with attending such meetings. Trustees and officers of the
Fund who are or have been employed by the Investment Manager or an affiliated
company receive no compensation or expense reimbursement from the Fund.
 
    The following table illustrates the compensation paid to the Fund's
Independent Trustees by the Fund for the fiscal year ended September 30, 1996.
 
                               FUND COMPENSATION
 
<TABLE>
<CAPTION>
                                                                   AGGREGATE
                                                                 COMPENSATION
NAME OF INDEPENDENT TRUSTEE                                      FROM THE FUND
- --------------------------------------------------------------  ---------------
<S>                                                             <C>
Michael Bozic.................................................      $1,750
Edwin J. Garn.................................................       1,850
John R. Haire.................................................       3,850
Dr. Manuel H. Johnson.........................................       1,800
Michael E. Nugent.............................................       1,750
John L. Schroeder.............................................       1,800
</TABLE>
 
   
    The following table illustrates the compensation paid to the Fund's
Independent Trustees for the calendar year ended December 31, 1996 for services
to the 82 Dean Witter Funds and, in the case of Messrs. Haire, Johnson, Nugent
and Schroeder, the 14 TCW/DW Funds that were in operation at December 31, 1996.
With respect to Messrs. Haire, Johnson, Nugent and Schroeder, the TCW/DW Funds
are included solely because of a limited exchange privilege between those Funds
and five Dean Witter Money Market Funds.
    
 
                                       10
<PAGE>
   
           CASH COMPENSATION FROM DEAN WITTER FUNDS AND TCW/DW FUNDS
    
 
   
<TABLE>
<CAPTION>
                                                                   FOR SERVICE AS    FOR SERVICE     TOTAL CASH
                                                                    CHAIRMAN OF          AS         COMPENSATION
                                                                   COMMITTEES OF     CHAIRMAN OF        PAID
                               FOR SERVICE                          INDEPENDENT     COMMITTEES OF   FOR SERVICES
                              AS DIRECTOR OR                         DIRECTORS/      INDEPENDENT         TO
                               TRUSTEE AND       FOR SERVICE AS     TRUSTEES AND    TRUSTEES AND       82 DEAN
                             COMMITTEE MEMBER     TRUSTEE AND          AUDIT            AUDIT          WITTER
                                OF 82 DEAN      COMMITTEE MEMBER   COMMITTEES OF    COMMITTEES OF     FUNDS AND
NAME OF                           WITTER          OF 14 TCW/DW     82 DEAN WITTER     14 TCW/DW       14 TCW/DW
INDEPENDENT TRUSTEE               FUNDS              FUNDS             FUNDS            FUNDS           FUNDS
- ---------------------------  ----------------   ----------------   --------------   -------------   -------------
Michael Bozic..............      $138,850           --                 --               --            $138,850
<S>                          <C>                <C>                <C>              <C>             <C>
Edwin J. Garn..............       140,900           --                 --               --             140,900
John R. Haire..............       106,400           $64,283           $195,450        $ 12,187         378,320
Dr. Manuel H. Johnson......       137,100            66,483            --               --             203,583
Michael E. Nugent..........       138,850            64,283            --               --             203,133
John L. Schroeder..........       137,150            69,083            --               --             206,233
</TABLE>
    
 
   
    As of the date of this Statement of Additional Information, 57 of the Dean
Witter Funds, including the Fund, have adopted a retirement program under which
an Independent Trustee who retires after serving for at least five years (or
such lesser period as may be determined by the Board) as an Independent Director
or Trustee of any Dean Witter Fund that has adopted the retirement program (each
such Fund referred to as an "Adopting Fund" and each such Trustee referred to as
an "Eligible Trustee") is entitled to retirement payments upon reaching the
eligible retirement age (normally, after attaining age 72). Annual payments are
based upon length of service. Currently, upon retirement, each Eligible Trustee
is entitled to receive from the Adopting Fund, commencing as of his or her
retirement date and continuing for the remainder of his or her life, an annual
retirement benefit (the "Regular Benefit") equal to 25.0% of his or her Eligible
Compensation plus 0.4166666% of such Eligible Compensation for each full month
of service as an Independent Director or Trustee of any Adopting Fund in excess
of five years up to a maximum of 50.0% after ten years of service. The foregoing
percentages may be changed by the Board.(1) "Eligible Compensation" is one-fifth
of the total compensation earned by such Eligible Trustee for service to the
Adopting Fund in the five year period prior to the date of the Eligible
Trustee's retirement. Benefits under the retirement program are not secured or
funded by the Adopting Funds.
    
 
   
    The following table illustrates the retirement benefits accrued to the
Fund's Independent Trustees by the Fund for the fiscal year ended September 30,
1995 and by the 57 Dean Witter Funds (including the Fund) for the year ended
December 31, 1996, and the estimated retirement benefits for the Fund's
Independent Trustees, to commence upon their retirement, from the Fund as of
September 30, 1995 and from the 57 Dean Witter Funds as of December 31, 1996.
    
 
   
          RETIREMENT BENEFITS FROM THE FUND AND ALL DEAN WITTER FUNDS
    
 
   
<TABLE>
<CAPTION>
                                                                               RETIREMENT BENEFITS
                                              FOR ALL ADOPTING FUNDS                                     ESTIMATED ANNUAL
                                      --------------------------------------   ACCRUED AS EXPENSES           BENEFITS
                                           ESTIMATED                                                    UPON RETIREMENT(2)
                                        CREDITED YEARS         ESTIMATED      ----------------------  ----------------------
                                         OF SERVICE AT       PERCENTAGE OF                  BY ALL      FROM      FROM ALL
                                          RETIREMENT           ELIGIBLE         BY THE     ADOPTING      THE      ADOPTING
NAME OF INDEPENDENT TRUSTEE              (MAXIMUM 10)        COMPENSATION        FUND        FUNDS      FUND        FUNDS
- ------------------------------------  -------------------  -----------------  -----------  ---------  ---------  -----------
<S>                                   <C>                  <C>                <C>          <C>        <C>        <C>
Michael Bozic.......................              10               50.0%       $     399   $  20,147  $     950  $    51,325
Edwin J. Garn.......................              10               50.0              589      27,772        950       51,325
John R. Haire.......................              10               50.0              699      46,952      2,343      129,550
Dr. Manuel H. Johnson...............              10               50.0              244      10,926        950       51,325
Michael E. Nugent...................              10               50.0              422      19,217        950       51,325
John L. Schroeder...................               8               41.7              776      38,700        792       42,771
</TABLE>
    
 
- ---------
   
(1) An Eligible Trustee may elect alternate payments of his or her retirement
    benefits based upon the combined life expectancy of such Eligible Trustee
    and his or her spouse on the date of such Eligible Trustee's retirement. The
    amount estimated to be payable under this method, through the remainder of
    the later of the lives of such Eligible Trustee and spouse, will be the
    actuarial equivalent of the Regular Benefit. In addition, the Eligible
    Trustee may elect that the surviving spouse's periodic payment of benefits
    will be equal to either 50% or 100% of the previous periodic amount, an
    election that, respectively, increases or decreases the previous periodic
    amount so that the resulting payments will be the actuarial equivalent of
    the Regular Benefit.
    
 
   
(2) Based on current levels of compensation. Amount of annual benefits also
    varies depending on the Trustee's elections described in Footnote (1) above.
    
 
                                       11
<PAGE>
   
    As of the date of this Statement of Additional Information, the aggregate
number of shares of beneficial interest of the Fund owned by the Fund's officers
and Trustees as a group was less than 1 percent of the Fund's shares of
beneficial interest outstanding.
    
 
INVESTMENT PRACTICES AND POLICIES
- --------------------------------------------------------------------------------
 
    CONVERTIBLE SECURITIES.  A convertible security entitles the holder to
exchange it for a fixed number of shares of common stock or other equity
security, usually of the same company, at fixed prices within a specified period
of time. As such, a convertible security entitles the holder to receive the
fixed income of a bond or the dividend preference of a preferred stock until the
holder elects to exercise the conversion privilege.
 
    A convertible security's position in a company's capital structure depends
upon its particular provisions. In the case of subordinated convertible
debentures, the holders' claims on assets and earnings are subordinated to the
claims of other creditors, and are senior to the claims of preferred and common
shareholders. In the case of convertible preferred stock, the holders' claims on
assets and earnings are subordinated to the claims of all creditors and are
senior to the claims of common shareholders.
 
    Every convertible security may be valued, on a theoretical basis, as if it
did not have a conversion privilege. Such theoretical value is determined by the
yield it provides in comparison with the yields of other securities of
comparable character and quality which do not have a conversion privilege. This
theoretical value, which will change with prevailing interest rates, the credit
standing of the issuer and other pertinent factors, is often referred to as the
"investment value," and represents the security's theoretical price support
level.
 
    "Conversion value" is the amount a convertible security would be worth in
market value if it were to be exchanged for the underlying equity security
pursuant to its conversion privilege. Conversion value fluctuates directly with
the price of the underlying equity security, usually common stock. If, because
of low prices for the common stock, the conversion value is substantially below
the investment value, the price of the convertible security is governed
principally by the factors described in the preceding paragraph. If the
conversion value rises near or above its investment value, the price of the
convertible security generally will rise above its investment value and, in
addition, will sell at some premium over its conversion value. This premium
represents the price investors are willing to pay for the privilege of
purchasing a fixed-income security with a possibility of capital appreciation
due to the conversion privilege. If this appreciation potential is not realized,
this premium may not be recovered.
 
    To the degree that the price of a convertible security rises above its
investment value because of a rise in price of the common stock, it is
influenced more by price fluctuations of the common stock and less by its
investment value. The price of a convertible security that is supported
principally by its conversion value will rise along with any increase in the
price of the common stock, and such price generally will decline along with any
decline in the price of the common stock except that the security will receive
additional support as its price approaches investment value. A convertible
security purchased or held at a time when its price is influenced by its
conversion value will produce a lower yield than nonconvertible senior
securities with comparable investment values. Convertible securities may be
purchased by the Fund at varying price levels above their investment values
and/or their conversion values in keeping with the Fund's investment objectives.
 
    CORPORATE FIXED-INCOME SECURITIES.  As discussed in the Prospectus, in order
to generate the current income needed to achieve its investment objective, the
Fund may invest in investment grade non-convertible fixed-income securities as
well as in such securities which are in the lower rating categories of
recognized rating agencies (Standard & Poor's Corporation and Moody's Investors
Service, Inc.) or which are not rated by such agencies. The Investment Manager
will perform its own credit analyses in addition to using recognized rating
agencies and other sources. In making such credit analyses, substantial
consideration will be given to a determination of value based upon, among other
 
                                       12
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things, anticipated cash flows, interest or dividend coverage, asset coverage,
earnings, experience of the issuer, responsiveness to changes in interest rates
and business conditions and liquidation value relative to the market price.
 
    WHEN, AS AND IF ISSUED SECURITIES.  As discussed in the Prospectus, the Fund
may purchase securities on a "when, as and if issued" basis under which the
issuance of the security depends upon the occurrence of a subsequent event, such
as approval of a merger, corporate reorganization, leveraged buyout or debt
restructuring. The commitment for the purchase of any such security will not be
recognized in the portfolio of the Fund until the Investment Manager determines
that issuance of the security is probable. At such time, the Fund will record
the transaction and, in determining its net asset value, will reflect the value
of the security daily. At such time, the Fund will also establish a segregated
account with its custodian bank in which it will maintain cash or cash
equivalents or other liquid portfolio securities equal in value to recognized
commitments for such securities. Once a segregated account has been established,
if the anticipated event does not occur and the securities are not issued, the
Fund will have lost an investment opportunity. The value of the Fund's
commitments to purchase the securities of any one issuer, together with the
value of all securities of such issuer owned by the Fund, may not exceed 5% of
the value of the Fund's total assets at the time the initial commitment to
purchase such securities is made (see "Investment Restrictions"). Subject to the
foregoing restrictions, the Fund may purchase securities on such basis without
limit. An increase in the percentage of the Fund's assets committed to the
purchase of securities on a "when, as and if issued" basis may increase the
volatility of its net asset value. The Investment Manager and the Trustees do
not believe that the net asset value of the Fund will be adversely affected by
its purchase of securities on such basis. The Fund may also sell securities on a
"when, as and if issued" basis provided that the issuance of the security will
result automatically from the exchange or conversion of a security owned by the
Fund at the time of sale.
 
OPTIONS AND FUTURES TRANSACTIONS
 
    The Fund may write covered call options against securities held in its
portfolio and covered put options on eligible portfolio securities and purchase
options of the same series to effect closing transactions, and may hedge against
potential changes in the market value of investments (or anticipated
investments) and facilitate the reallocation of the Fund's assets into and out
of equities and fixed-income securities by purchasing put and call options on
portfolio (or eligible portfolio) securities and engaging in transactions
involving futures contracts and options on such contracts.
 
    Call and put options on U.S. Treasury notes, bonds and bills and equity
securities are listed on Exchanges (currently the Chicago Board Options
Exchange, American Stock Exchange, New York Stock Exchange, Pacific Stock
Exchange and Philadelphia Stock Exchange) and are written in over-the-counter
transactions ("OTC Options"). Listed options are issued by the Options Clearing
Corporation ("OCC"). Ownership of a listed call option gives the Fund the right
to buy from the OCC the underlying security covered by the option at the stated
exercise price (the price per unit of the underlying security) by filing an
exercise notice prior to the expiration date of the option. The writer (seller)
of the option would then have the obligation to sell to the OCC the underlying
security at that exercise price prior to the expiration date of the option,
regardless of its then current market price. Ownership of a listed put option
would give the Fund the right to sell the underlying security to the OCC at the
stated exercise price. Upon notice of exercise of the put option, the writer of
the put would have the obligation to purchase the underlying security from the
OCC at the exercise price.
 
    OPTIONS ON TREASURY BONDS AND NOTES.  Because trading interest in options
written on Treasury bonds and notes tends to center on the most recently
auctioned issues, the exchanges on which such securities trade will not continue
indefinitely to introduce options with new expirations to replace expiring
options on particular issues. Instead, the expirations introduced at the
commencement of options trading on a particular issue will be allowed to run
their course, with the possible addition of a limited number of new expirations
as the original ones expire. Options trading on each issue of bonds or notes
will thus be phased out as new options are listed on more recent issues, and
options representing a full range of expirations will not ordinarily be
available for every issue on which options are traded.
 
                                       13
<PAGE>
    OPTIONS ON TREASURY BILLS.  Because a deliverable Treasury bill changes from
week to week, writers of Treasury bill calls cannot provide in advance for their
potential exercise settlement obligations by acquiring and holding the
underlying security. However, if the Fund holds a long position in Treasury
bills with a principal amount of the securities deliverable upon exercise of the
option, the position may be hedged from a risk standpoint by the writing of a
call option. For so long as the call option is outstanding, the Fund will hold
the Treasury bills in a segregated account with its Custodian, so that they will
be treated as being covered.
 
    OTC OPTIONS.  Exchange-listed options are issued by the OCC which assures
that all transactions in such options are properly executed. OTC options are
purchased from or sold (written) to dealers or financial institutions which have
entered into direct agreements with the Fund. With OTC options, such variables
as expiration date, exercise price and premium will be agreed upon between the
Fund and the transacting dealer, without the intermediation of a third party
such as the OCC. If the transacting dealer fails to make or take delivery of the
securities underlying an option it has written, in accordance with the terms of
that option, the Fund would lose the premium paid for the option as well as any
anticipated benefit of the transaction. The Fund will engage in OTC option
transactions only with primary U.S. Government securities dealers recognized by
the Federal Reserve Bank of New York.
 
   
    COVERED CALL WRITING.  The Fund is permitted to write covered call options
on portfolio securities, without limit, in order to aid in achieving its
investment objective. Generally, a call option is "covered" if the Fund owns, or
has the right to acquire, without additional cash consideration (or for
additional cash consideration held for the Fund by its Custodian in a segregated
account) the underlying security subject to the option except that in the case
of call options on U.S. Treasury bills, the Fund might own U.S. Treasury bills
of a different series from those underlying the call option, but with a
principal amount and value corresponding to the exercise price and a maturity
date no later than that of the securities deliverable under the call option. A
call option is also covered if the Fund holds a call on the same security as the
underlying security of the written option, where the exercise price of the call
used for coverage is equal to or less than the exercise price of the call
written or greater than the exercise price of the call written if the
mark-to-market difference is maintained by the Fund in cash, U.S. Government
securities or other liquid portfolio securities which the Fund holds in a
segregated account maintained with its Custodian.
    
 
    The Fund will receive from the purchaser, in return for a call it has
written, a "premium"; i.e., the price of the option. Receipt of these premiums
may better enable the Fund to achieve a greater total return than would be
realized from holding the underlying securities alone. Moreover, the premium
received will offset a portion of the potential loss incurred by the Fund if the
securities underlying the option are ultimately sold by the Fund at a loss. The
premium received will fluctuate with varying economic market conditions. If the
market value of the portfolio securities upon which call options have been
written increases, the Fund may receive less total return from the portion of
its portfolio upon which calls have been written than it would have had such
calls not been written.
 
    As regards listed options and certain over-the-counter ("OTC") options,
during the option period, the Fund may be required, at any time, to deliver the
underlying security against payment of the exercise price on any calls it has
written (exercise of certain listed options may be limited to specific
expiration dates). This obligation is terminated upon the expiration of the
option period or at such earlier time when the writer effects a closing purchase
transaction. A closing purchase transaction is accomplished by purchasing an
option of the same series as the option previously written. However, once the
Fund has been assigned an exercise notice, the Fund will be unable to effect a
closing purchase transaction.
 
    Closing purchase transactions are ordinarily effected to realize a profit on
an outstanding call option to prevent an underlying security from being called,
to permit the sale of an underlying security or to enable the Fund to write
another call option on the underlying security with either a different exercise
price or expiration date or both. Also, effecting a closing purchase transaction
will permit the cash or proceeds from the concurrent sale of any securities
subject to the option to be used for other investments by the Fund. The Fund may
realize a net gain or loss from a closing purchase transaction
 
                                       14
<PAGE>
depending upon whether the amount of the premium received on the call option is
more or less than the cost of effecting the closing purchase transaction. Any
loss incurred in a closing purchase transaction may be wholly or partially
offset by unrealized appreciation in the market value of the underlying
security. Conversely, a gain resulting from a closing purchase transaction could
be offset in whole or in part or exceeded by a decline in the market value of
the underlying security.
 
    If a call option expires unexercised, the Fund realizes a gain in the amount
of the premium on the option less the commission paid. Such a gain, however, may
be offset by depreciation in the market value of the underlying security during
the option period. If a call option is exercised, the Fund realizes a gain or
loss from the sale of the underlying security equal to the difference between
the purchase price of the underlying security and the proceeds of the sale of
the security plus the premium received on the option less the commission paid.
 
    Options written by a Fund normally have expiration dates of from up to nine
months (equity securities) to eighteen months (fixed-income securities) from the
date written. The exercise price of a call option may be below, equal to or
above the current market value of the underlying security at the time the option
is written. See "Risks of Options Transactions," below.
 
   
    COVERED PUT WRITING.  As a writer of a covered put option, the Fund incurs
an obligation to buy the security underlying the option from the purchaser of
the put, at the option's exercise price at any time during the option period, at
the purchaser's election (certain listed put options written by the Fund will be
exercisable by the purchaser only on a specific date). A put is "covered" if the
Fund maintains, in a segregated account maintained on its behalf at the Fund's
Custodian, cash, U.S. Government securities or other liquid portfolio securities
in an amount equal to at least the exercise price of the option, at all times
during the option period. Similarly, a written put position could be covered by
the Fund by its purchase of a put option on the same security as the underlying
security of the written option, where the exercise price of the purchased option
is equal to or more than the exercise price of the put written or less than the
exercise price of the put written if the mark-to-market difference is maintained
by the Fund in cash, U.S. Government securities or other high grade debt
obligations which the Fund holds in a segregated account maintained at its
Custodian. In writing puts, the Fund assumes the risk of loss should the market
value of the underlying security decline below the exercise price of the option
(any loss being decreased by the receipt of the premium on the option written).
During the option period, the Fund may be required, at any time, to make payment
of the exercise price against delivery of the underlying security. The operation
of and limitations on covered put options in other respects are substantially
identical to those of call options.
    
 
    The Fund will write put options for two purposes: (1) to receive the income
derived from the premiums paid by purchasers; and (2) when the Investment
Manager wishes to purchase the security underlying the option at a price lower
than its current market price, in which case it will write the covered put at an
exercise price reflecting the lower purchase price sought. The potential gain on
a covered put option is limited to the premium received on the option (less the
commissions paid on the transaction) while the potential loss equals the
difference between the exercise price of the option and the current market price
of the underlying securities when the put is exercised, offset by the premium
received (less the commissions paid on the transaction).
 
    PURCHASING CALL AND PUT OPTIONS.  The Fund may purchase listed call and put
options in amounts equalling up to 10% of its total assets. The Fund may
purchase call options only in order to close out a covered call position (see
"Covered Call Writing" above). The call purchased is likely to be on the same
securities and have the same terms as the written option. The option would
generally be acquired from the dealer or financial institution which purchased
the call written by the Fund.
 
    The Fund may purchase put options on securities which it holds (or has the
right to acquire) in its portfolio only to protect itself against a decline in
the value of the security. If the value of the underlying security were to fall
below the exercise price of the put purchased in an amount greater than the
premium paid for the option, the Fund would incur no additional loss. The Fund
may also purchase put
 
                                       15
<PAGE>
options to close out written put positions in a manner similar to call options
closing purchase transactions. In addition, the Fund may sell a put option which
it has previously purchased prior to the sale of the securities underlying such
option. Such a sale would result in a net gain or loss depending on whether the
amount received on the sale is more or less than the premium and other
transaction costs paid on the put option when it was purchased. Any such gain or
loss could be offset in whole or in part by a change in the market value of the
underlying security. If a put option purchased by the Fund expired without being
sold or exercised, the premium would be lost.
 
    RISKS OF OPTIONS TRANSACTIONS.  During the option period, the covered call
writer has, in return for the premium on the option, given up the opportunity
for capital appreciation above the exercise price should the market price of the
underlying security increase, but has retained the risk of loss should the price
of the underlying security decline. The secured put writer also retains the risk
of loss should the market value of the underlying security decline below the
exercise price of the option less the premium received on the sale of the
option. In both cases, the writer has no control over the time when it may be
required to fulfill its obligation as a writer of the option. Once an option
writer has received an exercise notice, it cannot effect a closing purchase
transaction in order to terminate its obligation under the option and must
deliver or receive the underlying securities at the exercise price.
 
   
    Prior to exercise or expiration, an option position can only be terminated
by entering into a closing purchase or sale transaction. If a covered call
option writer is unable to effect a closing purchase transaction it cannot sell
the underlying security until the option expires or the option is exercised.
Accordingly, a covered call option writer may not be able to sell an underlying
security at a time when it might otherwise be advantageous to do so. A covered
put option writer who is unable to effect a closing purchase transaction would
continue to bear the risk of decline in the market price of the underlying
security until the option expires or is exercised. In addition, a covered put
writer would be unable to utilize the amount held in cash or U.S. Government or
other liquid portfolio securities as cover for the put option for other
investment purposes until the exercise or expiration of the option.
    
 
    The Fund's ability to close out its position as a writer of an option is
dependent upon the existence of a liquid secondary market on option exchanges.
There is no assurance that such a market will exist. However, the Fund may be
able to purchase an offsetting option which does not close out its position as a
writer but constitutes an asset of equal value to the obligation under the
option written. If the Fund is not able to either enter into a closing purchase
transaction or purchase an offsetting position, it will be required to maintain
the securities subject to the call, or the collateral underlying the put, even
though it might not be advantageous to do so, until a closing transaction can be
entered into (or the option is exercised or expires). In addition, in the event
of the bankruptcy of a broker through which the Fund engages in transactions in
options, the Fund could experience delays and/or losses in liquidating open
positions purchased or sold through the broker and/or incur a loss of all or
part of its margin deposits with the broker.
 
    Among the possible reasons for the absence of a liquid secondary market on
an Exchange are: (i) insufficient trading interest in certain options; (ii)
restrictions on transactions imposed by an Exchange; (iii) trading halts,
suspensions or other restrictions imposed with respect to particular classes or
series of options or underlying securities; (iv) interruption of the normal
operations on an Exchange; (v) inadequacy of the facilities of an Exchange or
the Options Clearing Corporation ("OCC") to handle current trading volume; or
(vi) a decision by one or more Exchanges 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
OCC as a result of trades on that Exchange would generally continue to be
exercisable in accordance with their terms.
 
    In the event of the bankruptcy of a broker through which the Fund engages in
transactions in options, the Fund could experience delays and/or losses in
liquidating open positions purchased or sold through the broker and/or incur a
loss of all or part of its margin deposits with the broker. Similarly, in the
 
                                       16
<PAGE>
event of the bankruptcy of the writer of an OTC option purchased by the Fund,
the Fund could experience a loss of all or part of the value of the option.
Transactions are entered into by the Fund only with brokers or financial
institutions deemed creditworthy by the Investment Manager.
 
    Each of the Exchanges has established limitations governing the maximum
number of call or put options on the same underlying security or futures
contract (whether or not covered) which may be written by a single investor,
whether acting alone or in concert with others (regardless of whether such
options are written on the same or different Exchanges or are held or written on
one or more accounts or through one or more brokers). An Exchange may order the
liquidation of positions found to be in violation of these limits and it may
impose other sanctions or restrictions. These position limits may restrict the
number of listed options which the Fund may write.
 
    The hours of trading for options may not conform to the hours during which
the underlying securities are traded. To the extent that the option markets
close before the markets for the underlying securities, significant price and
rate movements can take place in the underlying markets that cannot be reflected
in the option markets.
 
    FUTURES CONTRACTS.  The Fund may purchase and sell futures contracts that
are traded on U.S. commodity exchanges on such underlying securities as U.S.
Treasury bonds, notes and bills. As a futures contract purchaser, the Fund
incurs an obligation to take delivery of a specified amount of the obligation
underlying the contract at a specified time in the future for a specified price.
As a seller of a futures contract, the Fund incurs an obligation to deliver the
specified amount of the underlying obligation at a specified time in return for
an agreed upon price.
 
    Although most futures contracts call for actual delivery or acceptance of
securities, the contracts usually are closed out before the settlement date
without the making or taking of delivery. A futures contract sale is closed out
by effecting a futures contract purchase for the same aggregate amount of the
specific type of security and the same delivery date. If the sale price exceeds
the offsetting purchase price, the seller would be paid the difference and would
realize a gain. If the offsetting purchase price exceeds the sale price, the
seller would pay the difference and would realize a loss. Similarly, a futures
contract purchase is closed out by effecting a futures contract sale for the
same aggregate amount of the specific type of security and the same delivery
date. If the offsetting sale price exceeds the purchase price, the purchaser
would realize a gain, whereas if the purchase price exceeds the offsetting sale
price, the purchaser would realize a loss. There is no assurance that the Fund
will be able to enter into a closing transaction.
 
    When the Fund enters into a futures contract, it is initially required to
deposit with the Fund's Custodian, in a segregated account in the name of the
broker performing the transaction, an "initial margin" of cash or U.S.
Government securities or other high grade short-term obligations equal to
approximately 2% of the contract amount. Initial margin requirements are
established by the Exchanges on which futures contracts trade and may, from time
to time, change. In addition, brokers may establish margin deposit requirements
in excess of those required by the Exchanges.
 
    Initial margin in futures transactions is different from margin in
securities transactions in that initial margin does not involve the borrowing of
funds by a brokers' client but is, rather, a good faith deposit on the futures
contract which will be returned to the Fund upon the proper termination of the
futures contract. The margin deposits made are mark-to-market daily and the Fund
may be required to make subsequent deposits of cash or U.S. Government
securities called "variation margin", with the Fund's futures contract clearing
broker, which are reflective of price fluctuations in the futures contract.
Currently, interest rate futures contracts can be purchased on debt securities
such as U.S. Treasury Bills and Bonds, U.S. Treasury Notes with maturities
between 6 1/2 and 10 years, GNMA Certificates and Bank Certificates of Deposit.
 
    OPTIONS ON FUTURES CONTRACTS.  The Fund may purchase and write call and put
options on futures contracts which are traded on an Exchange and enter into
closing transactions with respect to such options to terminate an existing
position. An option on a futures contract gives the purchaser the right (in
 
                                       17
<PAGE>
return for the premium paid), to assume a position in a futures contract (a long
position if the option is a call and a short position if the option is a put) at
a specified exercise price at any time during the term of the option. Upon
exercise of the option, the delivery of the futures position by the writer of
the option to the holder of the option is accompanied by delivery of the
accumulated balance in the writer's futures margin account, which represents the
amount by which the market price of the futures contract at the time of exercise
exceeds, in the case of a call, or is less than, in the case of a put, the
exercise price of the option on the futures contract.
 
    The Fund will purchase and write options on futures contracts for identical
purposes to those set forth above for the purchase of a futures contract
(purchase of a call option or sale of a put option) and the sale of a futures
contract (purchase of a put option or sale of a call option), or to close out a
long or short position in futures contracts. If, for example, the Investment
Manager wished to protect against an increase in interest rates and the
resulting negative impact on the value of a portion of its fixed-income
portfolio, it might write a call option on an interest rate futures contract,
the underlying security of which correlates with the portion of the portfolio
the Investment Manager seeks to hedge. Any premiums received in the writing of
options on futures contracts may, of course, augment the total return of the
Fund and thereby provide a further hedge against losses resulting from price
declines in portions of the Fund's portfolio.
 
    The writer of an option on a futures contract is required to deposit initial
and variation margin pursuant to requirements similar to those applicable to
futures contracts. Premiums received from the writing of an option on a futures
contract are included in initial margin deposits.
 
    LIMITATIONS ON FUTURES CONTRACTS AND OPTIONS ON FUTURES.  The Fund may not
enter into futures contracts or purchase related options thereon if, immediately
thereafter, the amount committed to margin plus the amount paid for premiums for
unexpired options on futures contracts exceeds 5% of the value of the Fund's
total assets, after taking into account unrealized gains and unrealized losses
on such contracts it has entered into, provided, however, that in the case of an
option that is in-the-money (the exercise price of the call (put) option is less
(more) than the market price of the underlying security) at the time of
purchase, the in-the-money amount may be excluded in calculating the 5%.
However, there is no overall limitation on the percentage of the Fund's assets
which may be subject to a hedge position. In addition, in accordance with the
regulations of the Commodity Futures Trading Commission ("CFTC") under which the
Fund is exempted from registration as a commodity pool operator, the Fund may
only enter into futures contracts and options on futures contracts transactions
for purposes of hedging a part or all of its portfolio. If the CFTC changes its
regulations so that the Fund would be permitted to write options on futures
contracts for purposes other than hedging the Fund's investments without CFTC
registration, the Fund may engage in such transactions for those purposes.
Except as described above, there are no other limitations on the use of futures
and options thereon by the Fund.
 
    RISKS OF TRANSACTIONS IN FUTURES CONTRACTS AND RELATED OPTIONS.  As stated
in the Prospectus, the Fund may sell a futures contract to protect against the
decline in the value of securities held by the Fund. However, it is possible
that the futures market may advance and the value of securities held in the
portfolio of the Fund may decline. If this occurred, the Fund would lose money
on the futures contract and also experience a decline in value of its portfolio
securities. However, while this could occur for a very brief period or to a very
small degree, over time the value of a diversified portfolio will tend to move
in the same direction as the futures contracts.
 
    If the Fund purchases a futures contract to hedge against the increase in
value of securities it intends to buy, and the value of such securities
decreases, then the Investment Manager may determine not to invest in the
securities as planned and will realize a loss on the futures contract that is
not offset by a reduction in the price of the securities.
 
    In order to assure that the Fund is entering into transactions in futures
contracts for hedging purposes as such is defined by the Commodities Futures
Trading Commission either: 1) a substantial majority (i.e., approximately 75%)
of all anticipatory hedge transactions (transactions in which the Fund does not
own at the time of the transaction, but expects to acquire, the securities
underlying the relevant
 
                                       18
<PAGE>
futures contract) involving the purchase of futures contracts will be completed
by the purchase of securities which are the subject of the hedge or 2) the
underlying value of all long positions in futures contracts will not exceed the
total value of: a) all short-term debt obligations held by the Fund; b) cash
held by the Fund; c) cash proceeds due to the Fund on investments within thirty
days; d) the margin deposited on the contracts; and e) any unrealized
appreciation in the value of the contracts.
 
    If the Fund maintains a short position in a futures contract or has sold a
call option on a futures contract, it will cover this position by holding, in a
segregated account maintained at its Custodian, cash, U.S. Government securities
or other high grade debt obligations equal in value (when added to any initial
or variation margin on deposit) to the market value of the securities underlying
the futures contract or the exercise price of the option. Such a position may
also be covered by owning the securities underlying the futures contract, or by
holding a call option permitting the Fund to purchase the same contract at a
price no higher than the price at which the short position was established.
 
   
    In addition, if the Fund holds a long position in a futures contract or has
sold a put option on a futures contract, it will hold cash, U.S. Government
securities or other liquid portfolio securities equal to the purchase price of
the contract or the exercise price of the put option (less the amount of initial
or variation margin on deposit) in a segregated account maintained for the Fund
by its Custodian. Alternatively, the Fund could cover its long position by
purchasing a put option on the same futures contract with an exercise price as
high or higher than the price of the contract held by the Fund.
    
 
    Exchanges limit the amount by which the price of a futures contract may move
on any day. If the price moves equal the daily limit on successive days, then it
may prove impossible to liquidate a futures position until the daily limit moves
have ceased. In the event of adverse price movements, the Fund would continue to
be required to make daily cash payments of variation margin on open futures
positions. In such situations, if the Fund has insufficient cash, it may have to
sell portfolio securities to meet daily variation margin requirements at a time
when it may be disadvantageous to do so. In addition, the Fund may be required
to take or make delivery of the instruments underlying futures contracts it
holds at a time when it is disadvantageous to do so. The inability to close out
options and futures positions could also have an adverse impact on the Fund's
ability to effectively hedge its portfolio. In addition, in the event of the
bankruptcy of a broker through which the Fund engages in transactions in futures
or options thereon, the Fund could experience delays and/or losses in
liquidating open positions purchased or sold through the broker and/or incur a
loss of all or part of its margin deposits with the broker.
 
    In the event of the bankruptcy of a broker through which the Fund engages in
transactions in futures or options thereon, the Fund could experience delays
and/or losses in liquidating open positions purchased or sold through the broker
and/or incur a loss of all or part of its margin deposits with the broker.
Similarly, in the event of the bankruptcy of the writer of an OTC option
purchased by the Fund, the Fund could experience a loss of all or part of the
value of the option. Transactions are entered into by the Fund only with brokers
or financial institutions deemed creditworthy by the Investment Manager.
 
    While the futures contracts and options transactions to be engaged in by the
Fund for the purpose of hedging the Fund's portfolio securities are not
speculative in nature, there are risks inherent in the use of such instruments.
One such risk which may arise in employing futures contracts to protect against
the price volatility of portfolio securities is that the prices of securities
and indexes subject to futures contracts (and thereby the futures contract
prices) may correlate imperfectly with the behavior of the cash prices of the
Fund's portfolio securities. Another such risk is that prices of futures
contracts may not move in tandem with the changes in prevailing interest rates
against which the Fund seeks a hedge. A correlation may also be distorted by the
fact that the futures market is dominated by short-term traders seeking to
profit from the difference between a contract or security price objective and
their cost of borrowed funds. Such distortions are generally minor and would
diminish as the contract approached maturity.
 
    There may exist an imperfect correlation between the price movements of
futures contracts purchased by the Fund and the movements in the prices of the
securities which are the subject of the
 
                                       19
<PAGE>
hedge. If participants in the futures market elect to close out their contracts
through offsetting transactions rather than meet margin deposit requirements,
distortions in the normal relationship between the debt securities and futures
markets could result. Price distortions could also result if investors in
futures contracts opt to make or take delivery of underlying securities rather
than engage in closing transactions due to the resultant reduction in the
liquidity of the futures market. In addition, due to the fact that, from the
point of view of speculators, the deposit requirements in the futures markets
are less onerous than margin requirements in the cash market, increased
participation by speculators in the futures market could cause temporary price
distortions. Due to the possibility of price distortions in the futures market
and because of the imperfect correlation between movements in the prices of
securities and movements in the prices of futures contracts, a correct forecast
of interest rate trends by the Investment Manager may still not result in a
successful hedging transaction.
 
    There is no assurance that a liquid secondary market will exist for futures
contracts and related options in which the Fund may invest. In the event a
liquid market does not exist, it may not be possible to close out a futures
position, and in the event of adverse price movements, the Fund would continue
to be required to make daily cash payments of variation margin. In addition,
limitations imposed by an exchange or board of trade on which futures contracts
are traded may compel or prevent the Fund from closing out a contract which may
result in reduced gain or increased loss to the Fund. The absence of a liquid
market in futures contracts might cause the Fund to make or take delivery of the
underlying securities at a time when it may be disadvantageous to do so.
 
    The extent to which the Fund may enter into transactions involving futures
contracts and options thereon may be limited by the Internal Revenue Code's
requirements for qualification as a regulated investment company and the Fund's
intention to qualify as such (see "Dividends, Distributions and Taxes" in the
Prospectus).
 
    Compared to the purchase or sale of futures contracts, the purchase of call
or put options on futures contracts involves less potential risk to the Fund
because the maximum amount at risk is the premium paid for the options (plus
transaction costs). However, there may be circumstances when the purchase of a
call or put option on a futures contract would result in a loss to the Fund
notwithstanding that the purchase or sale of a futures contract would not result
in a loss, as in the instance where there is no movement in the prices of the
futures contract or underlying securities.
 
    The Investment Manager has substantial experience in the use of the
investment techniques described above under the heading "Options and Futures
Transactions," which techniques require skills different from those needed to
select the portfolio securities underlying various options and futures
contracts.
 
LENDING OF PORTFOLIO SECURITIES
 
    Consistent with applicable regulatory requirements, the Fund may lend its
portfolio securities to brokers, dealers and other financial institutions,
provided that such loans are callable at any time by the Fund (subject to notice
provisions described below), and are at all times secured by cash or cash
equivalents, which are maintained in a segregated account pursuant to applicable
regulations and that are equal to at least the market value, determined daily,
of the loaned securities. The advantage of such loans is that the Fund continues
to receive the income on the loaned securities while at the same time earning
interest on the cash amounts deposited as collateral, which will be invested in
short-term obligations. The Fund will not lend its portfolio securities if such
loans are not permitted by the laws or regulations of any state in which its
shares are qualified for sale and will not lend more than 25% of the value of
its total assets.
 
    A loan may be terminated by the borrower on one business day's notice, or by
the Fund on two business days' notice. If the borrower fails to deliver the
loaned securities within two days after receipt of notice, the Trust could use
the collateral to replace the securities while holding the borrower liable for
any excess of replacement cost over collateral. As with any extensions of
credit, there are risks of delay in recovery and in some cases even loss of
rights in the collateral should the borrower of the securities fail
 
                                       20
<PAGE>
financially. However, these loans of portfolio securities will only be made to
firms deemed by the Fund's management to be creditworthy and when the income
which can be earned from such loans justifies the attendant risks. Upon
termination of the loan, the borrower is required to return the securities to
the Fund. Any gain or loss in the market price during the loan period would
inure to the Fund. The creditworthiness of firms to which the Fund lends its
portfolio securities will be monitored on an ongoing basis by the Investment
Manager pursuant to procedures adopted and reviewed, on an ongoing basis, by the
Trustees of the Fund.
 
    When voting or consent rights which accompany loaned securities pass to the
borrower, the Fund will follow the policy of calling the loaned securities, to
be delivered within one day after notice, to permit the exercise of such rights
if the matters involved would have a material effect on the Fund's investment in
such loaned securities. The Fund will pay reasonable finder's, administrative
and custodial fees in connection with a loan of its securities. However, the
Fund did not lend any of its portfolio securities during the fiscal year ended
September 30, 1996 and it has no intention of doing so in the foreseeable
future.
 
REPURCHASE AGREEMENTS
 
    When cash may be available for only a few days, it may be invested by the
Fund in repurchase agreements until such time as it may otherwise be invested or
used for payments of obligations of the Fund. These agreements, which may be
viewed as a type of secured lending by the Fund, typically involve the
acquisition by the Fund of debt securities from a selling financial institution
such as a bank, savings and loan association or broker-dealer. The agreement
provides that the Fund will sell back to the institution, and that the
institution will repurchase, the underlying security ("collateral"), which is
held by the Fund's Custodian, at a specified price and at a fixed time in the
future, usually not more than seven days from the date of purchase. The Fund
will receive interest from the institution until the time when the repurchase is
to occur. Although such date is deemed by the Fund to be the maturity date of a
repurchase agreement, the maturities of securities subject to repurchase
agreements are not subject to any limits and may exceed one year. While
repurchase agreements involve certain risks not associated with direct
investments in debt securities, the Fund follows procedures designed to minimize
such risks. These procedures include effecting repurchase transactions only with
large, well-capitalized and well-established financial institutions, whose
financial condition will be continually monitored by the Investment Manager
subject to procedures established by the Trustees. In addition, the value of the
collateral underlying the repurchase agreement will always be at least equal to
the repurchase price, including any accrued interest earned on the repurchase
agreement. In the event of a default or bankruptcy by a selling financial
institution, the Fund will seek to liquidate such collateral. However, the
exercising of the Fund's right to liquidate such collateral could involve
certain costs or delays and, to the extent that proceeds from any sale upon a
default of the obligation to repurchase were less than the repurchase price, the
Fund could suffer a loss. It is the current policy of the Fund not to invest in
repurchase agreements that do not mature within seven days if any such
investment, together with any other illiquid assets held by the Fund, amounts to
more than 10% of its total assets. The Fund's investments in repurchase
agreements may at times be substantial when, in the view of the Investment
Manager, liquidity or other considerations warrant. The Fund did not enter into
any repurchase agreements during the fiscal year ended September 30, 1996, in an
amount greater than 5% of its net assets.
 
ZERO COUPON SECURITIES
 
    A portion of the securities purchased by the Fund may be "zero coupon"
Treasury securities. These are U.S. Treasury bills, notes and bonds which have
been stripped of their unmatured interest coupons and receipts or which are
certificates representing interests in such stripped debt obligations and
coupons. "Zero coupon" securities are purchased at a discount from their face
amount, giving the purchaser the right to receive their full value at maturity.
A zero coupon security pays no interest to its holder during its life. Its value
to an investor consists of the difference between its face value at the time of
maturity and the price for which it was acquired, which is generally an amount
significantly less than its face value (sometimes referred to as a "deep
discount" price).
 
                                       21
<PAGE>
    The interest earned on such securities is, implicitly, automatically
compounded and paid out at maturity. While such compounding at a constant rate
eliminates the risk of receiving lower yields upon reinvestment of interest if
prevailing interest rates decline, the owner of a zero coupon security will be
unable to participate in higher yields upon reinvestment of interest received if
prevailing interest rates rise. For this reason, zero coupon securities are
subject to substantially greater market price fluctuations during periods of
changing prevailing interest rates than are comparable debt securities which
make current distributions of interest. Current federal tax law requires that a
holder (such as the Fund) of a zero coupon security accrue a portion of the
discount at which the security was purchased as income each year even though the
Fund receives no interest payments in cash on the security during the year.
 
    Currently the only U.S. Treasury security issued without coupons is the
Treasury bill. However, in the last few years a number of banks and brokerage
firms have separated ("stripped") the principal portions from the coupon
portions of the U.S. Treasury bonds and notes and sold them separately in the
form of receipts of certificates representing undivided interests in these
instruments (which instruments are generally held by a bank in a custodial or
trust account).
 
WARRANTS
 
    The Fund may invest up to 5% of its net assets in warrants, but not more
than 2% of such assets in warrants not listed on either the New York or American
Stock Exchange. However, the acquisition of warrants attached to other
securities is not subject to this limitation. For the fiscal year ended
September 30, 1996, the Fund's investments in warrants did not exceed 5% of its
net assets.
 
FOREIGN SECURITIES
 
    The Fund may invest in securities of foreign companies. However, the Fund
will not invest more than 10% of the value of its total assets, at the time of
purchase, in foreign securities (other than securities of Canadian issuers
registered under the Securities Exchange Act of 1934 or American Depository
Receipts, on which there is no such limit). Investments in certain Canadian
issuers may be speculative due to certain political risks and may be subject to
substantial price fluctuations. Foreign securities investments may be affected
by changes in currency rates or exchange control regulations, changes in
governmental administration or economic or monetary policy (in the United States
and abroad) or changed circumstances in dealings between nations. Costs may be
incurred in connection with conversions between various currencies held by the
Fund.
 
    The Fund may invest in securities of foreign companies. Dividends paid by
foreign issuers may be subject to withholding and other foreign taxes which may
decrease the net return on such investments as compared to dividends paid to the
Fund by domestic corporations. It should be noted that there may be less
publicly available information about foreign issuers than about domestic
issuers, and foreign issuers are not subject to uniform accounting, auditing and
financial reporting standards and requirements comparable to those of domestic
issuers. Securities of some foreign issuers are less liquid and more volatile
than securities of comparable domestic issuers and foreign brokerage commissions
are generally higher than in the United States. Foreign securities markets may
also be less liquid, more volatile and less subject to government supervision
than those in the United States. The Fund may be affected either unfavorably or
favorably by fluctuations in the relative rates of exchange as between the
currencies of different nations and exchange control regulations. Investments in
foreign countries could be affected by other factors not present in the United
States, including expropriation, confiscatory taxation and potential
difficulties in enforcing contractual obligations. Securities purchased on
foreign exchanges will be held in custody by a foreign branch of a domestic
bank. During the fiscal year ended September 30, 1996, the Fund did not purchase
any foreign securities in an amount greater than 5% of its net assets.
 
PORTFOLIO TURNOVER
 
    The Fund may sell portfolio securities without regard to the length of time
they have been held whenever such sale will, in the Investment Manager's
opinion, strengthen the Fund's position and contribute to its investment
objective. As a result, the Fund's portfolio turnover rate may exceed 100%. A
100% turnover rate would occur, for example, if 100% of the securities held in
the Fund's portfolio
 
                                       22
<PAGE>
(excluding all securities whose maturities at acquisition were one year or less)
were sold and replaced within one year. During the fiscal year ended September
30, 1996, the Fund's portfolio turnover rate was 170.61%.
 
INVESTMENT RESTRICTIONS
- --------------------------------------------------------------------------------
 
    In addition to the investment restrictions enumerated in the Prospectus, the
investment restrictions listed below have been adopted by the Fund as
fundamental policies, except as otherwise indicated. Under the Act, a
fundamental policy may not be changed without the vote of a majority of the
outstanding voting securities of the Fund, as defined in the Act. Such a
majority is defined as the lesser of (a) 67% or more of the shares present at a
meeting of shareholders, if the holders of 50% of the outstanding shares of the
Fund are present or represented by proxy or (b) more than 50% of the outstanding
shares of the Fund.
 
    The Fund may not:
 
         1. Invest in securities of any issuer if, to the knowledge of the Fund,
    any officer, or trustee/ director of the Fund or of the Investment Manager
    owns more than 1/2 of 1% of the outstanding securities of such issuer, and
    such officers and trustees/directors who own more than 1/2 of 1% own in the
    aggregate more than 5% of the outstanding securities of such issuer.
 
         2. Purchase or sell real estate or interests therein, although the Fund
    may purchase securities of issuers which engage in real estate operations
    and securities secured by real estate or interests therein.
 
         3. Purchase or sell commodities except that the Fund may purchase
    financial futures contracts and related options thereon.
 
         4. Purchase oil, gas or other mineral leases, rights or royalty
    contracts, or exploration or development programs, except that the Fund may
    invest in the securities of companies which operate, invest in, or sponsor
    such programs.
 
         5. Purchase securities of other investment companies, except in
    connection with a merger, consolidation, reorganization or acquisition of
    assets.
 
         6. Pledge its assets or assign or otherwise encumber them except to
    secure permitted borrowings. (For the purpose of this restriction,
    collateral arrangements with respect to the writing of options and
    collateral arrangements with respect to initial and variation margin for
    futures are not deemed to be pledges of assets and such arrangements are not
    deemed to be the issuance of a senior security as set forth in restriction
    (7).)
 
         7. Issue senior securities as defined in the Act except insofar as the
    Fund may be deemed to have issued a senior security by reason of: (a)
    entering into any repurchase agreement; (b) borrowing money in accordance
    with restrictions described above and in the Prospectus; (c) purchasing any
    securities on a when-issued or delayed delivery basis; or (d) lending
    portfolio securities.
 
         8. Make loans of money or securities, except: (a) by the purchase of
    debt obligations in which the Fund may invest consistent with its investment
    objectives and policies; (b) by investment in repurchase agreements; or (c)
    by lending its portfolio securities.
 
         9. Make short sales of securities or maintain a short position, unless
    at all times when a short position is open it either owns an equal amount of
    such securities or owns securities which, without payment of any further
    consideration, are convertible into or exchangeable for securities of the
    same issue as, and equal in amount to, the securities sold short.
 
                                       23
<PAGE>
        10. Purchase securities on margin, except for such short-term loans as
    are necessary for the clearance of portfolio securities. The deposit or
    payment by the Fund of initial or variation margin in connection with
    futures contracts or related options thereon is not considered the purchase
    of a security on margin.
 
        11. Engage in the underwriting of securities, except insofar as the Fund
    may be deemed an underwriter under the Securities Act of 1933 in disposing
    of a portfolio security.
 
        12. Invest for the purpose of exercising control or management of any
    other issuer.
 
    If a percentage restriction is adhered to at the time of investment, a later
increase or decrease in percentage resulting from a change in values of
portfolio securities or amount of total or net assets will not be considered a
violation of any of the foregoing restrictions.
 
   
    Notwithstanding any other investment policy or restriction, the Fund may
seek to achieve its investment objective by investing all or substantially all
of its assets in another investment company having substantially the same
investment objective and policies as the Fund.
    
 
PORTFOLIO TRANSACTIONS AND BROKERAGE
- --------------------------------------------------------------------------------
 
    Subject to the general supervision of the Trustees, the Investment Manager
is responsible for decisions to buy and sell securities and futures contracts
for the Fund, the selection of brokers and dealers to effect the transactions
and the negotiation of brokerage commissions, if any. Purchases and sales of
securities on a stock exchange are effected through brokers who charge a
commission for their services. In the over-the-counter market, securities are
generally traded on a "net" basis with dealers acting as principal for their own
accounts without a stated commission, although the price of the security usually
includes a profit to the dealer. Option and futures transactions will usually be
effected through a broker and a commission will be charged.
 
    The Fund also expects that securities will be purchased at times in
underwritten offerings where the price includes a fixed amount of compensation,
generally referred to as the underwriter's concession or discount. On occasion,
the Fund may also purchase certain money market instruments directly from an
issuer, in which case no commissions or discounts are paid.
 
    The Investment Manager currently serves as investment manager to a number of
clients, including other investment companies, and may in the future act as
investment manager or adviser to others. It is the practice of the Investment
Manager to cause purchase and sale transactions to be allocated among the Fund
and others whose assets it manages in such manner as it deems equitable. In
making such allocations among the Fund and other client accounts, various
factors may be considered, including are the respective investment objectives,
the relative size of portfolio holdings of the same or comparable securities,
the availability of cash for investment, the size of investment commitments
generally held and the opinions of the persons responsible for managing the
portfolios of the Fund and other client accounts. In the case of certain initial
and secondary public offerings, the Investment Manager may utilize a pro-rata
allocation process based on the size of the Dean Witter Funds involved and the
number of shares available from the public offering.
 
    The aggregate amount of brokerage commissions paid by the Fund during the
fiscal years ended September 30, 1994, 1995 and 1996 was $401,973, $233,311 and
$162,895, respectively.
 
    The policy of the Fund regarding purchases and sales of securities and
futures contracts for its portfolio is that primary consideration will be given
to obtaining the most favorable prices and efficient execution of transactions.
In seeking to implement the Fund's policies, the Investment Manager effects
transactions with those brokers and dealers who the Investment Manager believes
provide the most favorable prices and are capable of providing efficient
executions. If the Investment Manager believes such price and execution are
obtainable from more than one broker or dealer, it may give consideration to
placing portfolio transactions with those brokers and dealers who also furnish
research and other services to the Fund or the Investment Manager. Such services
may include, but are not limited to, any
 
                                       24
<PAGE>
one or more of the following: information as to the availability of securities
for purchase or sale; statistical or factual information or opinions pertaining
to investment; wire services; and appraisals or evaluations of portfolio
securities.
 
    The information and services received by the Investment Manager from brokers
and dealers may be of benefit to the Investment Manager in the management of
accounts of some of its other clients and may not in all cases benefit the Fund
directly. While the receipt of such information and services is useful in
varying degrees and would generally reduce the amount of research or services
otherwise performed by the Investment Manager and thereby reduce its expenses,
it is of indeterminable value and the management fee paid to the Investment
Manager is not reduced by any amount that may be attributable to the value of
such services. During the fiscal year ended September 30, 1996, the Fund
directed payment of $146,315 in brokerage commissions in connection with
transactions in the aggregate amount of $65,300,473 to brokers because of
research services provided.
 
    Pursuant to an order of the Securities and Exchange Commission, the Fund may
effect principal transactions in certain money market instruments with DWR. The
Fund will limit its transactions with DWR to U.S. Government and Government
Agency Securities, Bank Money Instruments (I.E., Certificates of Deposit and
Bankers' Acceptances) and Commercial Paper. Such transactions will be effected
with DWR only when the price available from DWR is better than that available
from other dealers.
 
   
    Consistent with the policy described above, brokerage transactions in
securities listed on exchanges or admitted to unlisted trading privileges may be
effected through DWR and other affiliated brokers and dealers. In order for an
affiliated broker or dealer to effect portfolio transactions for the Fund, the
commissions, fees or other remuneration received by the affiliated broker or
dealer must be reasonable and fair compared to the commissions, fees or other
remuneration paid to other brokers in connection with comparable transactions
involving similar securities being purchased or sold on an exchange during a
comparable period of time. This standard would allow the affiliated broker or
dealer to receive no more than the remuneration which would be expected to be
received by an unaffiliated broker in a commensurate arm's-length transaction.
Furthermore, the Trustees of the Fund, including a majority of the Trustees who
are not "interested" Trustees, have adopted procedures which are reasonably
designed to provide that any commissions, fees or other remuneration paid to an
affiliated broker or dealer are consistent with the foregoing standard. During
the fiscal years ended September 30, 1994, 1995 and 1996, the Fund paid a total
of $31,360, $27,100 and $11,922, respectively, in brokerage commissions to DWR.
The Fund does not reduce the management fee it pays to the Investment Manager by
any amount of the brokerage commissions it may pay to an affiliated broker or
dealer. During the fiscal year ended September 30, 1996, the brokerage
commissions paid to DWR represented approximately 7.32% of the total brokerage
commissions paid by the Fund during the year and were paid on account of
transactions having an aggregate dollar value equal to approximately 7.60% of
the aggregate dollar value of all portfolio transactions of the Fund during the
year for which commissions were paid.
    
 
THE DISTRIBUTOR
- --------------------------------------------------------------------------------
 
   
    As discussed in the Prospectus, shares of the Fund are distributed by Dean
Witter Distributors Inc. (the "Distributor"). The Distributor has entered into a
selected dealer agreement with DWR, which through its own sales organization
sells shares of the Fund. In addition, the Distributor may enter into selected
dealer agreements with other selected broker-dealers. The Distributor, a
Delaware corporation, is a wholly-owned subsidiary of MSDWD. The Trustees of the
Fund, including a majority of the Trustees who are not, and were not at the time
they voted, interested persons of the Fund, as defined in the Act (the
"Independent Trustees"), approved, at their meeting held on June 30, 1997, the
current Distribution Agreement appointing the Distributor as exclusive
distributor of the Fund's shares and providing for the Distributor to bear
distribution expenses not borne by the Fund. By its terms, the Distribution
Agreement has an initial term ending April 30, 1998 and will remain in effect
from year to year thereafter if approved by the Board.
    
 
                                       25
<PAGE>
   
    The Distributor bears all expenses it may incur in providing services under
the Distribution Agreement. Such expenses include the payment of commissions for
sales of the Fund's shares and incentive compensation to account executives. The
Distributor also pays certain expenses in connection with the distribution of
the Fund's shares, including the costs of preparing, printing and distributing
advertising or promotional materials, and the costs of printing and distributing
prospectuses and supplements thereto used in connection with the offering and
sale of the Fund's shares. The Fund bears the costs of initial typesetting,
printing and distribution of prospectuses and supplements thereto to
shareholders. The Fund also bears the costs of registering the Fund and its
shares under federal securities laws and pays filing fees in accordance with
state securities laws. The Fund and the Distributor have agreed to indemnify
each other against certain liabilities, including liabilities under the
Securities Act of 1933, as amended. Under the Distribution Agreement, the
Distributor uses its best efforts in rendering services to the Fund, but in the
absence of willful misfeasance, bad faith, gross negligence or reckless
disregard of its obligations, the Distributor is not liable to the Fund or any
of its shareholders for any error of judgment or mistake of law or for any act
or omission or for losses sustained by the Fund or its shareholders.
    
 
   
PLAN OF DISTRIBUTION
    
 
   
    The Fund has adopted a Plan of Distribution pursuant to Rule 12b-1 under the
Act (the "Plan") pursuant to which each Class, other than Class D, pays the
Distributor compensation accrued daily and payable monthly at the following
annual rates: 0.25% and 1.0% of the average daily net assets of Class A and
Class C, respectively, and, with respect to Class B, 1.0 % of the lesser of: (a)
the average daily aggregate gross sales of the Fund's Class B shares since the
inception of the Fund (not including reinvestments of dividends or capital gains
distributions), less the average daily aggregate net asset value of the Fund's
Class B shares redeemed since the Fund's inception upon which a contingent
deferred sales charge has been imposed or upon which such charge has been
waived, or (b) the average daily net assets of Class B. The Distributor also
receives the proceeds of front-end sales charges and of contingent deferred
sales charges imposed on certain redemptions of shares, which are separate and
apart from payments made pursuant to the Plan (see "Purchase of Fund Shares" in
the Prospectus). The Distributor has informed the Fund that it and/or DWR
received approximately $38,000, $76,212 and $144,945 in contingent deferred
sales charges for the fiscal years ended September 30, 1994, 1995, and 1996,
respectively, none of which was retained by the Distributor.
    
 
   
    The Distributor has informed the Fund that the entire fee payable by Class A
and a portion of the fees payable by each of Class B and Class C each year
pursuant to the Plan equal to 0.25% of such Class's average daily net assets are
currently each characterized as a "service fee" under the Rules of the
Association of the National Association of Securities Dealers, Inc. (of which
the Distributor is a member). The "service fee" is a payment made for personal
service and/or the maintenance of shareholder accounts. The remaining portion of
the Plan fees payable by a Class, if any, is characterized as an "asset-based
sales charge" as such is defined by the aforementioned Rules of the Association.
    
 
   
    The Plan was adopted by a majority vote of the Board of Trustees, including
all of the Trustees of the Fund who are not "interested persons" of the Fund (as
defined in the Act) and who have no direct or indirect financial interest in the
operation of the Plan (the "Independent 12b-1 Trustees"), cast in person at a
meeting called for the purpose of voting on the Plan, on April 17, 1996 and by
the shareholders holding a majority, as defined in the Act, of the outstanding
voting securities of the Fund at an Annual Meeting of Shareholders of the Fund
held on December 29, 1986.
    
 
   
    At their meeting held on October 30, 1992, the Trustees of the Fund,
including all of the Independent 12b-1 Trustees, approved certain amendments to
the Plan which took effect in January, 1993 and were designed to reflect the
fact that upon an internal reorganization the share distribution activities
theretofore performed for the Fund by DWR were assumed by the Distributor and
DWR's sales activities are now being performed pursuant to the terms of a
selected dealer agreement between the Distributor and DWR. The amendments
provide that payments under the Plan will be made to the Distributor rather than
to DWR as before the amendment, and that the Distributor in turn is authorized
to make payments to DWR, its affiliates or other selected broker-dealers (or
direct that the Fund pay such entities directly). The
    
 
                                       26
<PAGE>
Distributor is also authorized to retain part of such fee as compensation for
its own distribution-related expenses. At their meeting held on April 28, 1993,
the Trustees, including a majority of the Independent 12b-1 Trustees, approved
certain technical amendments to the Plan in connection with amendments adopted
by the National Association of Securities Dealers, Inc. to its Rules of the
Association. At their meeting held on October 26, 1995, the Trustees of the
Fund, including all of the Independent 12b-1 Trustees, approved an amendment to
the Plan to permit payments to be made under the Plan with respect to certain
distribution expenses incurred in connection with the distribution of shares,
including personal services to shareholders with respect to holdings of such
shares, of an investment company whose assets are acquired by the Fund in a
tax-free reorganization. At their meeting held on June 30, 1997, the Trustees,
including a majority of the Independent 12b-1 Trustees, approved amendments to
the Plan to reflect the multiple-class structure for the Fund, which took effect
on July 28, 1997.
 
   
    Under the Plan and as required by Rule 12b-1, the Trustees receive and
review promptly after the end of each calendar quarter a written report provided
by the Distributor of the amounts expended under the Plan and the purpose for
which such expenditures were made. The Fund accrued amounts payable to the
Distributor under the Plan, during the fiscal year ended September 30, 1996, of
$2,057,104. This amount is equal to 1.0% of the Fund's average daily net assets
for the fiscal year and was calculated pursuant to clause (b) of the
compensation formula under the Plan. This amount is treated by the Fund as an
expense in the year it is accrued. This amount represents amounts paid by Class
B only; there were no Class A or Class C shares outstanding on such date.
    
 
   
    The Plan was adopted in order to permit the implementation of the Fund's
method of distribution. Under this distribution method the Fund offers four
Classes of shares, each with a different distribution arrangement as set forth
in the Prospectus.
    
 
   
    With respect to Class A shares, DWR compensates its account executives by
paying them, from proceeds of the front-end sales charge, commissions for the
sale of Class A shares, currently a gross sales credit of up to 5.0% of the
amount sold (except as provided in the following sentence) and an annual
residual commission, currently a residual of up to 0.25% of the current value of
the respective accounts for which they are the account executives or dealers of
record in all cases. On orders of $1 million or more (for which no sales charge
was paid) or net asset value purchases by 401(k) plans or other
employer-sponsored plans qualified under Section 401(a) of the Internal Revenue
Code for which Dean Witter Trust Company ("DWTC") or Dean Witter Trust FSB
("DWTFSB") serves as Trustee or the 401(k) Support Services Group of DWR serves
as recordkeeper, the Investment Manager compensates DWR's account executives by
paying them, from its own funds, a gross sales credit of 1.0% of the amount
sold.
    
 
   
    With respect to Class B shares, DWR compensates its account executives by
paying them, from its own funds, commissions for the sale of Class B shares,
currently a gross sales credit of up to 5.0% of the amount sold (except as
provided in the following sentence) and an annual residual commission, currently
a residual of up to 0.25% of the current value (not including reinvested
dividends or distributions) of the amount sold in all cases. In the case of
retirement plans qualified under Section 401(k) of the Internal Revenue Code and
other employer-sponsored plans qualified under Section 401(a) of the Internal
Revenue Code for which DWTC or DWTFSB serves as Trustee or the 401(k) Support
Services Group of DWR serves as recordkeeper, and which plans are opened on or
after July 28, 1997, DWR compensates its account executives by paying them, from
its own funds, a gross sales credit of 3.0% of the amount sold.
    
 
   
    With respect to Class C shares, DWR compensates its account executives by
paying them, from its own funds, commissions for the sale of Class C shares,
currently a gross sales credit of up to 1.0% of the amount sold and an annual
residual commission, currently a residual of up to 1.0% of the current value of
the respective accounts for which they are the account executives of record.
    
 
   
    With respect to Class D shares other than shares held by participants in
InterCapital's mutual fund asset allocation program, the Investment Manager
compensates DWR's account executives by paying them, from its own funds,
commissions for the sale of Class D shares, currently a gross sales credit of up
    
 
                                       27
<PAGE>
   
to 1.0% of the amount sold. There is a chargeback of 100% of the amount paid if
the Class D shares are redeemed in the first year and a chargeback of 50% of the
amount paid if the Class D shares are redeemed in the second year after
purchase. The Investment Manager also compensates DWR's account executives by
paying them, from its own funds, an annual residual commission, currently a
residual of up to 0.10% of the current value of the respective accounts for
which they are the account executives of record (not including accounts of
participants in the InterCapital mutual fund asset allocation program).
    
 
   
    The gross sales credit is a charge which reflects commissions paid by DWR to
its account executives and DWR's Fund-associated distribution-related expenses,
including sales compensation, and overhead and other branch office
distribution-related expenses including (a) the expenses of operating DWR's
branch offices in connection with the sale of Fund shares, including lease
costs, the salaries and employee benefits of operations and sales support
personnel, utility costs, communications costs and the costs of stationery and
supplies, (b) the costs of client sales seminars, (c) travel expenses of mutual
fund sales coordinators to promote the sale of Fund shares and (d) other
expenses relating to branch promotion of Fund sales. The distribution fee that
the Distributor receives from the Fund under the Plan, in effect, offsets
distribution expenses incurred under the Plan on behalf of the Fund and, in the
case of Class B shares, opportunity costs, such as the gross sales credit and an
assumed interest charge thereon ("carrying charge"). In the Distributor's
reporting of the distribution expenses to the Fund, in the case of Class B
shares, such assumed interest (computed at the "broker's call rate") has been
calculated on the gross credit as it is reduced by amounts received by the
Distributor under the Plan and any contingent deferred sales charges received by
the Distributor upon redemption of shares of the Fund. No other interest charge
is included as a distribution expense in the Distributor's calculation of its
distribution costs for this purpose. The broker's call rate is the interest rate
charged to securities brokers on loans secured by exchange-listed securities.
    
 
   
    The Fund paid 100% of the $2,057,104 accrued under the Plan for the fiscal
year ended September 30, 1996 to the Distributor. The Distributor and DWR
estimate that they have spent, pursuant to the Plan, $164,729,040 on behalf of
the Fund since the inception of the Fund. It is estimated that this amount was
spent in approximately the following ways: (i) 1.51% ($2,494,229) -- advertising
and promotional expenses; (ii) 0.33% ($546,760) printing of prospectuses for
distribution to other than current shareholders; and (iii) 98.16% ($161,688,051)
- -- other expenses, including the gross sales credit and the carrying charge, of
which 25.97% ($41,986,304) represents carrying charges, 30.32% ($49,018,091)
represents commission credits to DWR branch offices for payments of commissions
to account executives, 42.80% ($69,211,748) represents overhead and other branch
office distribution-related expenses and 0.91% ($1,471,908) represents excess
distribution expenses of TCW/DW Global Convertible Trust, the net assets of
which were combined with those of the Fund on December 22, 1995 pursuant to an
Agreement and Plan of Reorganization. These amounts represent amounts paid by
Class B only; there were no Class A or Class C shares outstanding on such date.
    
 
   
    The Fund is authorized to reimburse expenses incurred or to be incurred in
promoting the distribution of the Fund's Class A and Class C shares and in
servicing shareholder accounts. Reimbursement will be made through payments at
the end of each month. The amount of each monthly payment may in no event exceed
an amount equal to a payment at the annual rate of 0.25%, in the case of Class
A, and 1.0%, in the case of Class C, of the average net assets of the respective
Class during the month. No interest or other financing charges, if any, incurred
on any distribution expenses on behalf of Class A and Class C will be
reimbursable under the Plan. With respect to Class A, in the case of all
expenses other than expenses representing the service fee, and, with respect to
Class C, in the case of all expenses other than expenses representing a gross
sales credit or a residual to account executives, such amounts shall be
determined at the beginning of each calendar quarter by the Trustees, including
a majority of the Independent 12b-1 Trustees. Expenses representing the service
fee (for Class A) or a gross sales credit or a residual to account executives
(for Class C) may be reimbursed without prior determination. In the event that
the Distributor proposes that monies shall be reimbursed for other than such
expenses, then in making quarterly determinations of the amounts that may be
reimbursed by the Fund, the Distributor
    
 
                                       28
<PAGE>
   
will provide and the Trustees will review a quarterly budget of projected
distribution expenses to be incurred on behalf of the Fund, together with a
report explaining the purposes and anticipated benefits of incurring such
expenses. The Trustees will determine which particular expenses, and the
portions thereof, that may be borne by the Fund, and in making such a
determination shall consider the scope of the Distributor's commitment to
promoting the distribution of the Fund's Class A and Class C shares.
    
 
   
    At any given time, the expenses of distributing shares of the Fund may be
more or less than the total of (i) the payments made by the Fund pursuant to the
Plan and (ii) the proceeds of contingent deferred sales charges paid by
investors upon redemption of shares. The Distributor has advised the Fund that
in the case of Class B shares the excess distribution expenses, including the
carrying charge designed to approximate the opportunity costs incurred by DWR
which arise from it having advanced monies without having received the amount of
any sales charges imposed at the time of sale of the Fund's Class B shares,
totalled $71,800,910 as of September 30, 1996 . Because there is no requirement
under the Plan that the Distributor be reimbursed for all distribution expenses
with respect to Class B shares or any requirement that the Plan be continued
from year to year, this excess amount does not constitute a liability of the
Fund. Although there is no legal obligation for the Fund to pay expenses
incurred in excess of payments made to the Distributor under the Plan and the
proceeds of contingent deferred sales charges paid by investors upon redemption
of shares, if for any reason the Plan is terminated, the Trustees will consider
at that time the manner in which to treat such expenses. Any cumulative expenses
incurred, but not yet recovered through distribution fees or contingent deferred
sales charges, may or may not be recovered through future distribution fees or
contingent deferred sales charges.
    
 
    No interested person of the Fund nor any Trustee of the Fund who is not an
interested person of the Fund, as defined in the Act, has any direct financial
interest in the operation of the Plan except to the extent that the Distributor,
InterCapital, DWR, DWSC or certain of their employees may be deemed to have such
an interest as a result of benefits derived from the successful operation of the
Plan or as a result of receiving a portion of the amounts expended thereunder by
the Fund.
 
   
    Under its terms, the Plan had an initial term ending December 31, 1985 and
will continue from year to year thereafter, provided such continuance is
approved annually by a vote of the Trustees in the manner described above. Prior
to the Board's approval of amendments to the Plan to reflect the multiple-class
structure for the Fund, the most recent continuance of the Plan for one year,
until April 30, 1998, was approved by the Board of Trustees of the Fund,
including a majority of the Independent 12b-1 Trustees, at a Board meeting held
on April 24, 1997. Prior to approving the continuation of the Plan, the Trustees
requested and received from the Distributor and reviewed all the information
which they deemed necessary to arrive at an informed determination. In making
their determination to continue the Plan, the Trustees considered: (1) the
Fund's experience under the Plan and whether such experience indicates that the
Plan is operating as anticipated; (2) the benefits the Fund had obtained, was
obtaining and would be likely to obtain under the Plan; and (3) what services
had been provided and were continuing to be provided under the Plan to the Fund
and its shareholders. Based upon their review, the Trustees of the Fund,
including each of the Independent 12b-1 Trustees, determined that continuation
of the Plan would be in the best interest of the Fund and would have a
reasonable likelihood of continuing to benefit the Fund and its shareholders. In
the Trustees' quarterly review of the Plan, they will consider its continued
appropriateness and the level of compensation provided therein.
    
 
   
    The Plan may not be amended to increase materially the amount to be spent
for the services described therein without approval by the shareholders of the
affected Class or Classes of the Fund, and all material amendments to the Plan
must also be approved by the Trustees in the manner described above. The Plan
may be terminated at any time, without payment of any penalty, by vote of a
majority of the Independent 12b-1 Trustees or by a vote of a majority of the
outstanding voting securities of the Fund (as defined in the Act) on not more
than thirty days' written notice to any other party to the Plan. So long as the
Plan is in effect, the election and nomination of Independent 12b-1 Trustees
shall be committed to the discretion of the Independent 12b-1 Trustees.
    
 
                                       29
<PAGE>
   
DETERMINATION OF NET ASSET VALUE
    
 
    As stated in the Prospectus, short-term securities with remaining maturities
of sixty days or less at the time of purchase are valued at amortized cost,
unless the Trustees determine such does not reflect the securities' market
value, in which case these securities will be valued at their fair value as
determined by the Trustees. Other short-term debt securities will be valued on a
mark-to-market basis until such time as they reach a remaining maturity of sixty
days, whereupon they will be valued at amortized cost using their value on the
61st day unless the Trustees determine such does not reflect the securities'
market value, in which case these securities will be valued at their fair value
as determined by the Trustees. Listed options on debt securities are valued at
the latest sale price on the exchange on which they are listed unless no sales
of such options have taken place that day, in which case they will be valued at
the mean between their latest bid and asked prices. Unlisted options on debt
securities and all options on equity securities are valued at the mean between
their latest bid and asked prices. Futures are valued at the latest sale price
on the commodities exchange on which they trade unless the Trustees determine
such price does not reflect their market value, in which case they will be
valued at their fair value as determined by the Trustees. All other securities
and other assets are valued at their fair value as determined in good faith
under procedures established by and under the supervision of the Trustees.
 
   
    The net asset value per share for each Class of shares of the Fund is
determined once daily at 4:00 p.m. New York time (or, on days when the New York
Stock Exchange closes prior to 4:00 p.m., at such earlier time), on each day
that the New York Stock Exchange is open and on each other day in which there is
a sufficient degree of trading in the Fund's investments to affect the net asset
value, except that the net asset value may not be computed on a day on which no
orders to purchase, or tenders to sell or redeem, Fund shares have been
received, by taking the value of all assets of the Fund, subtracting its
liabilities, dividing by the number of shares outstanding and adjusting to the
nearest cent. The New York Stock Exchange currently observes the following
holidays: New Year's Day; Reverend Dr. Martin Luther King, Jr. Day; President's
Day; Good Friday; Memorial Day; Independence Day; Labor Day; Thanksgiving Day;
and Christmas Day.
    
 
   
PURCHASE OF FUND SHARES
    
- --------------------------------------------------------------------------------
 
   
    As discussed in the Prospectus, the Fund offers four Classes of shares as
follows:
    
 
   
INITIAL SALES CHARGE ALTERNATIVE--CLASS A SHARES
    
 
   
    Class A shares are sold to investors with an initial sales charge that
declines to zero for larger purchases; however, Class A shares sold without an
initial sales charge are subject to a contingent deferred sales charge ("CDSC")
of 1.0% if redeemed within one year of purchase, except in the circumstances
discussed in the Prospectus.
    
 
   
    RIGHT OF ACCUMULATION.  As discussed in the Prospectus, investors may
combine the current value of shares purchased in separate transactions for
purposes of benefitting from the reduced sales charges available for purchases
of shares of the Fund totalling at least $25,000 in net asset value. For
example, if any person or entity who qualifies for this privilege holds Class A
shares of the Fund and/or other Dean Witter Funds that are multiple class funds
("Dean Witter Multi-Class Funds") or shares of other Dean Witter Funds sold with
a front-end sales charge purchased at a price including a front-end sales charge
having a current value of $5,000, and purchases $20,000 of additional shares of
the Fund, the sales charge applicable to the $20,000 purchase would be 4.75% of
the offering price.
    
 
   
    The Distributor must be notified by the selected broker-dealer or the
shareholder at the time a purchase order is placed that the purchase qualifies
for the reduced charge under the Right of Accumulation. Similar notification
must be made in writing by the selected broker-dealer or shareholder when such
an order is placed by mail. The reduced sales charge will not be granted if: (a)
such notification is not furnished at the time of the order; or (b) a review of
the records of the Distributor or Dean Witter Trust Company (the "Transfer
Agent") fails to confirm the investor's represented holdings.
    
 
                                       30
<PAGE>
   
    LETTER OF INTENT.  As discussed in the Prospectus, reduced sales charges are
available to investors who enter into a written Letter of Intent providing for
the purchase, within a thirteen-month period, of Class A shares of the Fund from
the Distributor or from a single Selected Broker-Dealer.
    
 
   
    A Letter of Intent permits an investor to establish a total investment goal
to be achieved by any number of purchases over a thirteen-month period. Each
purchase of Class A shares made during the period will receive the reduced sales
commission applicable to the amount represented by the goal, as if it were a
single purchase. A number of shares equal in value to 5% of the dollar amount of
the Letter of Intent will be held in escrow by the Transfer Agent, in the name
of the shareholder. The initial purchase under a Letter of Intent must be equal
to at least 5% of the stated investment goal.
    
 
   
    The Letter of Intent does not obligate the investor to purchase, nor the
Fund to sell, the indicated amount. In the event the Letter of Intent goal is
not achieved within the thirteen-month period, the investor is required to pay
the difference between the sales charge otherwise applicable to the purchases
made during this period and sales charges actually paid. Such payment may be
made directly to the Distributor or, if not paid, the Distributor is authorized
by the shareholder to liquidate a sufficient number of his or her escrowed
shares to obtain such difference.
    
 
   
    If the goal is exceeded and purchases pass the next sales charge level, the
sales charge on the entire amount of the purchase that results in passing that
level and on subsequent purchases will be subject to further reduced sales
charges in the same manner as set forth above under "Right of Accumulation," but
there will be no retroactive reduction of sales charges on previous purchases.
For the purpose of determining whether the investor is entitled to a further
reduced sales charge applicable to purchases at or above a sales charge level
which exceeds the stated goal of a Letter of Intent, the cumulative current net
asset value of any shares owned by the investor in any other Dean Witter Funds
held by the shareholder which were previously purchased at a price including a
front-end sales charge (including shares of the Fund and other Dean Witter Funds
acquired in exchange for those shares, and including in each case shares
acquired through reinvestment of dividends and distributions) will be added to
the cost or net asset value of shares of the Fund owned by the investor.
However, shares of "Exchange Funds" (see "Shareholder Services--Exchange
Privilege") and the purchase of shares of other Dean Witter Funds will not be
included in determining whether the stated goal of a Letter of Intent has been
reached.
    
 
   
    At any time while a Letter of Intent is in effect, a shareholder may, by
written notice to the Distributor, increase the amount of the stated goal. In
that event, only shares purchased during the previous 90-day period and still
owned by the shareholder will be included in the new sales charge reduction. The
5% escrow and minimum purchase requirements will be applicable to the new stated
goal. Investors electing to purchase shares of the Fund pursuant to a Letter of
Intent should carefully read such Letter of Intent.
    
 
   
CONTINGENT DEFERRED SALES CHARGE ALTERNATIVE--CLASS B SHARES
    
 
   
    Class B shares are sold without an initial sales charge but are subject to a
CDSC payable upon most redemptions within six years after purchase. As stated in
the Prospectus, a CDSC will be imposed on any redemption by an investor if after
such redemption the current value of the investor's Class B shares of the Fund
is less than the dollar amount of all payments by the shareholder for the
purchase of Class B shares during the preceding six years (or, in the case of
shares held by certain employer-sponsored benefit plans, three years). However,
no CDSC will be imposed to the extent that the net asset value of the shares
redeemed does not exceed: (a) the current net asset value of shares purchased
more than six years (or, in the case of shares held by certain
employer-sponsored benefit plans, three years) prior to the redemption, plus (b)
the current net asset value of shares purchased through reinvestment of
dividends or distributions of the Fund or another Dean Witter Fund (see
"Shareholder Services-- Targeted Dividends"), plus (c) the current net asset
value of shares acquired in exchange for (i) shares of Dean Witter front-end
sales charge funds, or (ii) shares of other Dean Witter Funds for which shares
of front-end sales charge funds have been exchanged (see "Shareholder
Services--Exchange Privilege"), plus (d) increases in the net asset value of the
investor's shares above the total amount of payments for
    
 
                                       31
<PAGE>
   
the purchase of Fund shares made during the preceding six (three) years. The
CDSC will be paid to the Distributor. In addition, no CDSC will be imposed on
redemptions of shares which are attributable to reinvestment of dividends or
distributions from, or the proceeds of, certain Unit Investment Trusts.
    
 
   
    In determining the applicability of the CDSC to each redemption, the amount
which represents an increase in the net asset value of the investor's shares
above the amount of the total payments for the purchase of shares within the
last six years (or, in the case of shares held by certain employer-sponsored
benefit plans, three years) will be redeemed first. In the event the redemption
amount exceeds such increase in value, the next portion of the amount redeemed
will be the amount which represents the net asset value of the investor's shares
purchased more than six (three) years prior to the redemption and/or shares
purchased through reinvestment of dividends or distributions and/or shares
acquired in exchange for shares of Dean Witter front-end sales charge funds, or
for shares of other Dean Witter funds for which shares of front-end sales charge
funds have been exchanged. A portion of the amount redeemed which exceeds an
amount which represents both such increase in value and the value of shares
purchased more than six years (or, in the case of shares held by certain
employer-sponsored benefit plans, three years) prior to the redemption and/or
shares purchased through reinvestment of dividends or distributions and/or
shares acquired in the above-described exchanges will be subject to a CDSC.
    
 
   
    The amount of the CDSC, if any, will vary depending on the number of years
from the time of payment for the purchase of Class B shares of the Fund until
the time of redemption of such shares. For purposes of determining the number of
years from the time of any payment for the purchase of shares, all payments made
during a month will be aggregated and deemed to have been made on the last day
of the month. The following table sets forth the rates of the CDSC applicable to
most Class B shares of the Fund:
    
 
   
<TABLE>
<CAPTION>
                                        YEAR SINCE
                                         PURCHASE                                            CDSC AS A PERCENTAGE OF
                                       PAYMENT MADE                                              AMOUNT REDEEMED
- ------------------------------------------------------------------------------------------  --------------------------
<S>                                                                                         <C>
First.....................................................................................               5.0%
Second....................................................................................               4.0%
Third.....................................................................................               3.0%
Fourth....................................................................................               2.0%
Fifth.....................................................................................               2.0%
Sixth.....................................................................................               1.0%
Seventh and thereafter....................................................................             None
</TABLE>
    
 
   
    The following table sets forth the rates of the CDSC applicable to Class B
shares of the Fund held by 401(k) plans or other employer-sponsored plans
qualified under Section 401(a) of the Internal Revenue Code for which DWTC or
DWTFSB serves as Trustee or the 401(k) Support Services Group of DWR serves as
recordkeeper and whose accounts are opened on or after July 28, 1997:
    
 
   
<TABLE>
<CAPTION>
                                        YEAR SINCE
                                         PURCHASE                                            CDSC AS A PERCENTAGE OF
                                       PAYMENT MADE                                              AMOUNT REDEEMED
- ------------------------------------------------------------------------------------------  --------------------------
<S>                                                                                         <C>
First.....................................................................................               2.0%
Second....................................................................................               2.0%
Third.....................................................................................               1.0%
Fourth and thereafter.....................................................................             None
</TABLE>
    
 
   
    In determining the rate of the CDSC, it will be assumed that a redemption is
made of shares held by the investor for the longest period of time within the
applicable six-year or three-year period. This will result in any such CDSC
being imposed at the lowest possible rate. The CDSC will be imposed, in
accordance with the table shown above, on any redemptions within six years (or,
in the case of shares held by certain employer-sponsored benefit plans, three
years) of purchase which are in excess of these amounts and which redemptions do
not qualify for waiver of the CDSC, as described in the Prospectus.
    
 
                                       32
<PAGE>
   
LEVEL LOAD ALTERNATIVE--CLASS C SHARES
    
 
   
    Class C shares are sold without a sales charge but are subject to a CDSC of
1.0% on most redemptions made within one year after purchase, except in the
circumstances discussed in the Prospectus.
    
 
   
NO LOAD ALTERNATIVE--CLASS D SHARES
    
 
   
    Class D shares are offered without any sales charge on purchase or
redemption. Class D shares are offered only to those persons meeting the
qualifications set forth in the Prospectus.
    
 
SHAREHOLDER SERVICES
- --------------------------------------------------------------------------------
 
   
    Upon the purchase of shares of the Fund, a Shareholder Investment Account is
opened for the investor on the books of the Fund and maintained by the Transfer
Agent. This is an open account in which shares owned by the investor are
credited by the Transfer Agent in lieu of issuance of a share certificate. If a
share certificate is desired, it must be requested in writing for each
transaction. Certificates are issued only for full shares and may be redeposited
in the account at any time. There is no charge to the investor for issuance of a
certificate. Whenever a shareholder instituted transaction takes place in the
Shareholder Investment Account, the shareholder will be mailed a confirmation of
the transaction from the Fund or from DWR or other selected broker-dealer.
    
 
   
    AUTOMATIC INVESTMENT OF DIVIDENDS AND DISTRIBUTIONS.  As stated in the
Prospectus, all income dividends and capital gains distributions are
automatically paid in full and fractional shares of the applicable Class of the
Fund, unless the shareholder requests that they be paid in cash. Each purchase
of shares of the Fund is made upon the condition that the Transfer Agent is
thereby automatically appointed as agent of the investor to receive all
dividends and capital gains distributions on shares owned by the investor. Such
dividends and distributions will be paid, at the net asset value per share, in
shares of the applicable Class of the Fund (or in cash if the shareholder so
requests) as of the close of business on the record date. At any time an
investor may request the Transfer Agent, in writing, to have subsequent
dividends and/or capital gains distributions paid to him or her in cash rather
than shares. To assure sufficient time to process the change, such request
should be received by the Transfer Agent at least five business days prior to
the record date of the dividend or distribution. In the case of recently
purchased shares for which registration instructions have not been received on
the record date, cash payments will be made to DWR or other selected
broker-dealer, and will be forwarded to the shareholder, upon the receipt of
proper instructions.
    
 
   
    TARGETED DIVIDENDS.-SM-  In states where it is legally permissible,
shareholders may also have all income dividends and capital gains distributions
automatically invested in shares of any Class of an open-end Dean Witter Fund
other than Dean Witter Convertible Securities Trust or in another Class of Dean
Witter Convertible Securities Trust. Such investment will be made as described
above for automatic investment in shares of the applicable Class of the Fund, at
the net asset value per share of the selected Dean Witter Fund as of the close
of business on the payment date of the dividend or distribution and will begin
to earn dividends, if any, in the selected Dean Witter Fund the next business
day. To participate in the Targeted Dividends program, shareholders should
contact their DWR or other selected broker-dealer account executive or the
Transfer Agent. Shareholders of the Fund must be shareholders of the selected
Class of the Dean Witter Fund targeted to receive investments from dividends at
the time they enter the Targeted Dividends program. Investors should review the
prospectus of the targeted Dean Witter Fund before entering the program.
    
 
   
    EASYINVEST.-SM-  Shareholders may subscribe to EasyInvest, an automatic
purchase plan which provides for any amount from $100 to $5,000 to be
transferred automatically from a checking or savings account or following
redemption of shares of a Dean Witter money market fund, on a semi-monthly,
monthly or quarterly basis, to the Transfer Agent for investment in shares of
the Fund. Shares purchased through EasyInvest will be added to the shareholder's
existing account at the net asset value calculated
    
 
                                       33
<PAGE>
the same business day the transfer of funds is effected. For further information
or to subscribe to EasyInvest, shareholders should contact their DWR or other
selected broker-dealer account executive or the Transfer Agent.
 
   
    INVESTMENT OF DIVIDENDS OR DISTRIBUTIONS RECEIVED IN CASH.  Any shareholder
who receives a cash payment representing a dividend or distribution may invest
such dividend or distribution in shares of the applicable Class at the net asset
value, without the imposition of a CDSC upon redemption, by returning the check
or the proceeds to the Transfer Agent within thirty days after the payment date.
If the shareholder returns the proceeds of a dividend or distribution, such
funds must be accompanied by a signed statement indicating that the proceeds
constitute a dividend or distribution to be invested. Such investment will be
made at the net asset value per share next determined after receipt of the
proceeds by the Transfer Agent.
    
 
   
    SYSTEMATIC WITHDRAWAL PLAN.  As discussed in the Prospectus, a systematic
withdrawal plan (the "Withdrawal Plan") is available for shareholders who own or
purchase shares of the Fund having a minimum value of $10,000 based upon the
then current net asset value. The Withdrawal Plan provides for monthly or
quarterly (March, June, September and December) checks in any dollar amount, not
less than $25, or in any whole percentage of the account balance, on an
annualized basis. Any applicable CDSC will be imposed on shares redeemed under
the Withdrawal Plan (see "Purchase of Fund Shares"). Therefore, any shareholder
participating in the Withdrawal Plan will have sufficient shares redeemed from
his or her account so that the proceeds (net of any applicable CDSC) to the
shareholder will be the designated monthly or quarterly amount.
    
 
    The Transfer Agent acts as agent for the shareholder in tendering to the
Fund for redemption sufficient full and fractional shares to provide the amount
of the periodic withdrawal payment designated in the application. The shares
will be redeemed at their net asset value determined, at the shareholder's
option, on the tenth or twenty-fifth day (or next following business day) of the
relevant month or quarter and normally a check for the proceeds will be mailed
by the Transfer Agent, or amounts credited to a shareholder's DWR or other
selected broker-dealer brokerage account, within five business days after the
date of redemption. The Withdrawal Plan may be terminated at any time by the
Fund.
 
    Withdrawal Plan payments should not be considered as dividends, yields or
income. If periodic withdrawal plan payments continuously exceed net investment
income and net capital gains, the shareholder's original investment will be
correspondingly reduced and ultimately exhausted.
 
   
    Each withdrawal constitutes a redemption of shares and any gain or loss
realized must be recognized for federal income tax purposes. Although the
shareholder may make additional investments of $2,500 or more under the
Withdrawal Plan, withdrawals made concurrently with purchases of additional
shares may be inadvisable because of the sales charges which may be applicable
to purchases or redemptions of shares (see "Purchase of Fund Shares").
    
 
   
    Any shareholder who wishes to have payments under the Withdrawal Plan made
to a third party or sent to an address other than the one listed on the account
must send complete written instructions to the Transfer Agent to enroll in the
Withdrawal Plan. The shareholder's signature on such instructions must be
guaranteed by an eligible guarantor acceptable to the Transfer Agent
(shareholders should contact the Transfer Agent for a determination as to
whether a particular institution is such an eligible guarantor). A shareholder
may, at any time, change the amount and interval of withdrawal payments through
his or her account executive or by written notification to the Transfer Agent.
In addition, the party and/or the address to which checks are mailed may be
changed by written notification to the Transfer Agent, with signature guarantees
required in the manner described above. The shareholder may also terminate the
Withdrawal Plan at any time by written notice to the Transfer Agent. In the
event of such termination, the account will be continued as a regular
shareholder investment account. The shareholder may also redeem all or part of
the shares held in the Withdrawal Plan account (see "Redemptions and
Repurchases" in the Prospectus) at any time. Shareholders wishing to enroll in
the Withdrawal Plan should contact their account executive or the Transfer
Agent.
    
 
                                       34
<PAGE>
   
    DIRECT INVESTMENTS THROUGH TRANSFER AGENT.  As discussed in the Prospectus,
shareholders may make additional investments in any Class of shares of the Fund
for which they qualify at any time by sending a check in any amount, not less
than $100, payable to Dean Witter Convertible Securities Trust, and indicating
the selected Class, directly to the Fund's Transfer Agent. In the case of Class
A shares, after deduction of any applicable sales charge, the balance will be
applied to the purchase of Fund shares, and, in the case of shares of the other
Classes, the entire amount will be applied to the purchase of Fund shares, at
the net asset value per share next computed after receipt of the check or
purchase payment by the Transfer Agent. The shares so purchased will be credited
to the investor's account.
    
 
    TAX-SHELTERED RETIREMENT PLANS.  Retirement plans are available for use by
corporations, the self-employed, Individual Retirement Accounts and Custodial
Accounts under Section 403(b)(7) of the Internal Revenue Code. Adoption of such
plans should be on advice of legal counsel or tax adviser.
 
   
    For further information regarding plan administration, custodial fees and
other details, investors should contact their DWR or other selected
broker-dealer account executive or the Transfer Agent.
    
 
   
EXCHANGE PRIVILEGE
    
 
   
    As discussed in the Prospectus, the Fund makes available to its shareholders
an Exchange Privilege whereby shareholders of each Class of shares of the Fund
may exchange their shares for shares of the same Class of shares of any other
Dean Witter Multi-Class Fund without the imposition of any exchange fee. Shares
may also be exchanged for shares of any of the following funds: Dean Witter
Short-Term U.S. Treasury Trust, Dean Witter Limited Term Municipal Trust, Dean
Witter Short-Term Bond Fund, Dean Witter Intermediate Term U.S. Treasury Trust
and five Dean Witter Funds which are money market funds (the foregoing nine
funds are hereinafter referred to as the "Exchange Funds"). Class A shares may
also be exchanged for shares of Dean Witter Multi-State Municipal Series Trust
and Dean Witter Hawaii Municipal Trust, which are Dean Witter Funds sold with a
front-end sales charge ("FSC Funds"). Class B shares may also be exchanged for
shares of Dean Witter Global Short-Term Income Fund Inc., Dean Witter High
Income Securities and Dean Witter National Municipal Trust, which are Dean
Witter Funds offered with a CDSC ("CDSC Funds"). Exchanges may be made after the
shares of the Fund acquired by purchase (not by exchange or dividend
reinvestment) have been held for thirty days. There is no waiting period for
exchanges of shares acquired by exchange or dividend reinvestment. An exchange
will be treated for federal income tax purposes the same as a repurchase or
redemption of shares, on which the shareholder may realize a capital gain or
loss.
    
 
    Any new account established through the Exchange Privilege will have the
same registration and cash dividend or dividend reinvestment plan as the present
account, unless the Transfer Agent receives written notification to the
contrary. For telephone exchanges, the exact registration of the existing
account and the account number must be provided.
 
    Any shares held in certificate form cannot be exchanged but must be
forwarded to the Transfer Agent and deposited into the shareholder's account
before being eligible for exchange. (Certificates mailed in for deposit should
not be endorsed.)
 
   
    As described below, and in the Prospectus under the caption "Purchase of
Fund Shares," a CDSC may be imposed upon a redemption, depending on a number of
factors, including the number of years from the time of purchase until the time
of redemption or exchange ("holding period"). When shares of a Dean Witter
Multi-Class Fund or any CDSC Fund are exchanged for shares of an Exchange Fund,
the exchange is executed at no charge to the shareholder, without the imposition
of the CDSC at the time of the exchange. During the period of time the
shareholder remains in the Exchange Fund (calculated from the last day of the
month in which the Exchange Fund shares were acquired), the holding period or
"year since purchase payment made" is frozen. When shares are redeemed out of
the Exchange Fund, they will be subject to a CDSC which would be based upon the
period of time the shareholder held shares in a Dean Witter Multi-Class Fund or
in a CDSC Fund. However, in the case of shares exchanged into an Exchange Fund
on or after April 23, 1990, upon a redemption of shares which results in a CDSC
being imposed, a credit (not to exceed the amount of the CDSC) will be given in
an amount equal to the
    
 
                                       35
<PAGE>
   
Exchange Fund 12b-1 distribution fees incurred on or after that date which are
attributable to those shares. Shareholders acquiring shares of an Exchange Fund
pursuant to this exchange privilege may exchange those shares back into a Dean
Witter Multi-Class Fund or a CDSC Fund from the Exchange Fund, with no CDSC
being imposed on such exchange. The holding period previously frozen when shares
were first exchanged for shares of the Exchange Fund resumes on the last day of
the month in which shares of a Dean Witter Multi-Class Fund or of a CDSC Fund
are reacquired. A CDSC is imposed only upon an ultimate redemption, based upon
the time (calculated as described above) the shareholder was invested in a Dean
Witter Multi-Class Fund or in a CDSC Fund. In the case of exchanges of Class A
shares which are subject to a CDSC, the holding period also includes the time
(calculated as described above) the shareholder was invested in a FSC Fund.
    
 
   
    When shares initially purchased in a Dean Witter Multi-Class Fund or in a
CDSC Fund are exchanged for shares of a Dean Witter Multi-Class Fund, shares of
a CDSC Fund, shares of a FSC Fund, or shares of an Exchange Fund, the date of
purchase of the shares of the fund exchanged into, for purposes of the CDSC upon
redemption, will be the last day of the month in which the shares being
exchanged were originally purchased. In allocating the purchase payments between
funds for purposes of the CDSC, the amount which represents the current net
asset value of shares at the time of the exchange which were (i) purchased more
than one, three or six years (depending on the CDSC schedule applicable to the
shares) prior to the exchange, (ii) originally acquired through reinvestment of
dividends or distributions and (iii) acquired in exchange for shares of FSC
Funds, or for shares of other Dean Witter Funds for which shares of FSC Funds
have been exchanged (all such shares called "Free Shares"), will be exchanged
first. After an exchange, all dividends earned on shares in an Exchange Fund
will be considered Free Shares. If the exchanged amount exceeds the value of
such Free Shares, an exchange is made, on a block-by-block basis, of non-Free
Shares held for the longest period of time (except that, with respect to Class B
shares, if shares held for identical periods of time but subject to different
CDSC schedules are held in the same Exchange Privilege account, the shares of
that block that are subject to a lower CDSC rate will be exchanged prior to the
shares of that block that are subject to a higher CDSC rate). Shares equal to
any appreciation in the value of non-Free Shares exchanged will be treated as
Free Shares, and the amount of the purchase payments for the non-Free Shares of
the fund exchanged into will be equal to the lesser of (a) the purchase payments
for, or (b) the current net asset value of, the exchanged non-Free Shares. If an
exchange between funds would result in exchange of only part of a particular
block of non-Free Shares, then shares equal to any appreciation in the value of
the block (up to the amount of the exchange) will be treated as Free Shares and
exchanged first, and the purchase payment for that block will be allocated on a
pro rata basis between the non-Free Shares of that block to be retained and the
non-Free Shares to be exchanged. The prorated amount of such purchase payment
attributable to the retained non-Free Shares will remain as the purchase payment
for such shares, and the amount of purchase payment for the exchanged non-Free
Shares will be equal to the lesser of (a) the prorated amount of the purchase
payment for, or (b) the current net asset value of, those exchanged non-Free
Shares. Based upon the procedures described in the Prospectus under the caption
"Purchase of Fund Shares," any applicable CDSC will be imposed upon the ultimate
redemption of shares of any fund, regardless of the number of exchanges since
those shares were originally purchased.
    
 
    With respect to the redemption or repurchase of shares of the Fund, the
application of proceeds to the purchase of new shares in the Fund or any other
of the funds and the general administration of the Exchange Privilege, the
Transfer Agent acts as agent for the Distributor and for the shareholder's
selected broker-dealer, if any, in the performance of such functions. With
respect to exchanges, redemptions or repurchases, the Transfer Agent shall be
liable for its own negligence and not for the default or negligence of its
correspondents or for losses in transit. The Fund shall not be liable for any
default or negligence of the Transfer Agent, the Distributor or any selected
broker-dealer.
 
    The Distributor and any selected broker-dealer have authorized and appointed
the Transfer Agent to act as their agent in connection with the application of
proceeds of any redemption of Fund shares to the
 
                                       36
<PAGE>
purchase of shares of any other fund and the general administration of the
Exchange Privilege. No commission or discounts will be paid to the Distributor
or any selected broker-dealer for any transactions pursuant to this Exchange
Privilege.
 
   
    Exchanges are subject to the minimum investment requirement and any other
conditions imposed by each fund. (The minimum initial investment for the
Exchange Privilege account of each Class is $5,000 for Dean Witter Liquid Asset
Fund Inc., Dean Witter Tax-Free Daily Income Trust, Dean Witter California
Tax-Free Daily Income Trust and Dean Witter New York Municipal Money Market
Trust, although those funds may, in their discretion, accept initial investments
of as low as $1,000. The minimum initial investment for the Exchange Privilege
account of each Class is $10,000 for Dean Witter Short-Term U.S. Treasury Trust,
although that fund, in its discretion, may accept initial purchases of as low as
$5,000. The minimum initial investment for the Exchange Privilege account of
each Class is $5,000 for Dean Witter Special Value Fund. The minimum initial
investment for the Exchange Privilege account of each Class of all other Dean
Witter Funds for which the Exchange Privilege is available is $1,000.) Upon
exchange into an Exchange Fund, the shares of that fund will be held in a
special Exchange Privilege Account separately from accounts of those
shareholders who have acquired their shares directly from that fund. As a
result, certain services normally available to shareholders of those funds,
including the check writing feature, will not be available for funds held in
that account.
    
 
    The Fund and each of the other Dean Witter Funds may limit the number of
times this Exchange Privilege may be exercised by any investor within a
specified period of time. Also, the Exchange Privilege may be terminated or
revised at any time by the Fund and/or any of the Dean Witter funds for
whichshares of the Fund have been exchanged, upon such notice as may be required
by applicable regulatory agencies (presently sixty days' prior written notice
for termination or material revision), provided that six months' prior written
notice of termination will be given to the shareholders who hold shares of
Exchange Funds pursuant to the Exchange Privilege, and provided further that the
Exchange Privilege may be terminated or materially revised without notice at
times (a) when the New York Stock Exchange is closed for other than customary
weekends and holidays, (b) when trading on that Exchange is restricted, (c) when
an emergency exists as a result of which disposal by the Fund of securities
owned by it is not reasonably practicable or it is not reasonably practicable
for the Fund fairly to determine the value of its net assets, (d) during any
other period when the Securities and Exchange Commission by order so permits
(provided that applicable rules and regulations of the Securities and Exchange
Commission shall govern as to whether the conditions prescribed in (b) or (c)
exist) or (e) if the Fund would be unable to invest amounts effectively in
accordance with its investment objective, policies and restrictions.
 
    For further information regarding the Exchange Privilege, shareholders
should contact their DWR or other selected broker-dealer account executive or
the Transfer Agent.
 
   
REDEMPTIONS AND REPURCHASES
    
- --------------------------------------------------------------------------------
 
   
    REDEMPTION.  As stated in the Prospectus, shares of each Class of the Fund
can be redeemed for cash at any time at the net asset value per share next
determined; however, such redemption proceeds will be reduced by the amount of
any applicable CDSC (see below). If shares are held in a shareholder's account
without a share certificate, a written request for redemption to the Fund's
Transfer Agent at P.O. Box 983, Jersey City, NJ 07303 is required. If
certificates are held by the shareholder, the shares may be redeemed by
surrendering the certificates with a written request for redemption. The share
certificate, or an accompanying stock power, and the request for redemption,
must be signed by the shareholder or shareholders exactly as the shares are
registered. Each request for redemption, whether or not accompanied by a share
certificate, must be sent to the Fund's Transfer Agent, which will redeem the
shares at their net asset value next computed (see "Purchase of Fund Shares" in
the Prospectus) after it receives the request, and certificate, if any, in good
order. Any redemption request received after such computation will be redeemed
at the next determined net asset value.
    
 
    Whether certificates are held by the shareholder or shares are held in a
shareholder's account, if the proceeds are to be paid to any person other than
the record owner, or if the proceeds are to be paid to a
 
                                       37
<PAGE>
   
corporation (other than the Distributor or a selected broker-dealer for the
account of the shareholder), partnership, trust or fiduciary, or sent to the
shareholder at an address other than the registered address, signatures must be
guaranteed by an eligible guarantor acceptable to the Transfer Agent
(shareholders should contact the Transfer Agent for a determination as to
whether a particular institution is such an eligible guarantor). A stock power
may be obtained from any dealer or commercial bank. The Fund may change the
signature guarantee requirements from time to time upon notice to shareholders,
which may be by means of a supplement to the prospectus or a new prospectus.
    
 
   
    REPURCHASE.  As stated in the Prospectus, DWR and other selected
broker-dealers are authorized to repurchase shares represented by a share
certificate which is delivered to any of their offices. Shares held in a
shareholder's account without a share certificate may also be repurchased by DWR
and other selected broker-dealers upon the telephonic request of the
shareholder. The repurchase price is the net asset value next computed after
such purchase order is received by DWR or other selected broker-dealer reduced
by any applicable CDSC.
    
 
   
    PAYMENT FOR SHARES REDEEMED OR REPURCHASED.  As discussed in the Prospectus,
payment for shares of any Class presented for repurchase or redemption will be
made by check within seven days after receipt by the Transfer Agent of the
certificate and/or written request in good order. The term good order means that
the share certificate, if any, and request for redemption are properly signed,
accompanied by any documentation required by the Transfer Agent, and bear
signature guarantees when required by the Fund or the Transfer Agent. Such
payment may be postponed or the right of redemption suspended at times (a) when
the New York Stock Exchange is closed for other than customary weekends and
holidays, (b) when trading on that Exchange is restricted, (c) when an emergency
exists as a result of which disposal by the Fund of securities owned by it is
not reasonably practicable or it is not reasonably practicable for the Fund
fairly to determine the value of its net assets, or (d) during any other period
when the Securities and Exchange Commission by order so permits; provided that
applicable rules and regulations of the Securities and Exchange Commission shall
govern as to whether the conditions prescribed in (b) or (c) exist. If the
shares to be redeemed have recently been purchased by check (including a
certified or bank cashier's check), payment of redemption proceeds may be
delayed for the minimum time needed to verify that the check used for investment
has been honored (not more than fifteen days from the time of receipt of the
check by the Transfer Agent). Shareholders maintaining margin accounts with DWR
or another selected broker-dealer are referred to their account executive
regarding restrictions on redemption of shares of the Fund pledged in the margin
account.
    
 
   
    TRANSFERS OF SHARES.  In the event a shareholder requests a transfer of
shares to a new registration, such shares will be transferred without sales
charge at the time of transfer. With regard to the status of shares which are
either subject to the CDSC or free of such charge (and with regard to the length
of time shares subject to the charge have been held), any transfer involving
less than all of the shares in an account will be made on a pro rata basis (that
is, by transferring shares in the same proportion that the transferred shares
bear to the total shares in the account immediately prior to the transfer). The
transferred shares will continue to be subject to any applicable CDSC as if they
had not been so transferred.
    
 
   
    REINSTATEMENT PRIVILEGE.  As discussed in the Prospectus, a shareholder who
has had his or her shares redeemed or repurchased and has not previously
exercised this reinstatement privilege may within 35 days after the date of
redemption or repurchase reinstate any portion or all of the proceeds of such
redemption or repurchase in shares of the Fund in the same Class at the net
asset value next determined after the reinstatement request, together with such
proceeds, is received by the Transfer Agent.
    
 
    Exercise of the reinstatement privilege will not affect the federal income
tax treatment of any gain or loss realized upon redemption or repurchase, except
that if the redemption or repurchase resulted in a loss and reinstatement is
made in shares of the Fund, some or all of the loss, depending on the amount
reinstated, will not be allowed as a deduction for federal income tax purposes
but will be applied to adjust the cost basis of the shares acquired upon
reinstatement.
 
                                       38
<PAGE>
DIVIDENDS, DISTRIBUTIONS AND TAXES
- --------------------------------------------------------------------------------
 
    As discussed in the Prospectus, the Fund will determine either to distribute
or to retain all or part of any net long-term capital gains in any year for
reinvestment. If any such gains are retained, the Fund will pay federal income
tax thereon, and will notify shareholders that following an election by the
Fund, the shareholders will be required to include such undistributed gains in
determining their taxable income and may claim their share of the tax paid by
the Fund as a credit against their individual federal income tax.
 
    Because the Fund intends to distribute all of its net investment income and
capital gains to shareholders and otherwise continue to qualify as a regulated
investment company under Subchapter M of the Internal Revenue Code, it is not
expected that the Fund will be required to pay any federal income tax.
Shareholders will normally have to pay federal income taxes, and any state
income taxes, on the dividends and distributions they receive from the Fund.
Such dividends and distributions, to the extent that they are derived from net
investment income or short-term capital gains, are taxable to the shareholder as
ordinary income regardless of whether the shareholder receives such payments in
additional shares or in cash. Any dividends declared in the last calendar
quarter of any year to shareholder of record for that period which are paid in
the following calendar year prior to February 1 will be deemed received by the
shareholder in the prior calendar year.
 
    Gains or losses on the sales of securities by the Fund will be long-term
capital gains or losses if the securities have been held by the Fund for more
than twelve months. Gains or losses on the sale of securities held for twelve
months or less will be short-term capital gains or losses.
 
    Distributions of net long-term capital gains, if any, are taxable to
shareholders as long-term capital gains regardless of how long a shareholder has
held the Fund's shares and regardless of whether the distribution is received in
additional shares or in cash. Capital gains distributions are not eligible for
the dividends received deduction.
 
    The Fund has qualified and intends to remain qualified as a regulated
investment company under Subchapter M of the Internal Revenue Code of 1986 (the
"Code"). If so qualified, the Fund will not be subject to federal income tax on
its net investment income and net short-term capital gains, if any, realized
during any fiscal year in which it distributes such income and capital gains to
its shareholders.
 
    Any dividend or capital gains distribution received by a shareholder from
any investment company will have the effect of reducing the net asset value of
the shareholder's stock in that company by the exact amount of the dividend or
capital gains distribution. Furthermore, capital gains distributions and
dividends are subject to federal income taxes. If the net asset value of the
shares should be reduced below a shareholder's cost as a result of the payment
of dividends or the distribution of realized long-term capital gains, such
payment or distribution would be in part a return of the shareholder's
investment to the extent of such reduction below the shareholder's cost, but
nonetheless would be fully taxable at either ordinary or capital gain rates.
Therefore, an investor should consider the tax implications of purchasing Fund
shares immediately prior to a dividend or distribution record date.
 
    Dividend payments will be eligible for the federal dividends received
deduction available to the Fund's corporate shareholders only to the extent the
aggregate dividends received by the Fund would be eligible for the deduction if
the Fund were the shareholder claiming the dividends received deduction. The
amount of dividends paid by the Fund which may qualify for the dividends
received deduction is limited to the aggregate amount of qualifying dividends
which the Fund derives from its portfolio investments which the Fund has held to
a minimum period, usually 46 days. Any distributions made by the Fund will not
be eligible for the dividends received deduction with respect to shares which
are held by the shareholder for 45 days or less. Any long-term capital gain
distributions will also not be eligible for the dividends received deduction.
The ability to take the dividends received deduction will also be limited in the
case of a Fund shareholder which incurs or continues indebtedness which is
directly attributable to its investment in the Fund.
 
                                       39
<PAGE>
    After the end of the year, shareholders will be sent full information on
their dividends and capital gains distributions for tax purposes, including
information as to the portion taxable as ordinary income, the portion taxable as
long-term capital gains and the portion eligible for the dividends received
deduction. To avoid being subject to a 31% federal backup withholding tax on
taxable dividends, capital gains distributions and the proceeds of redemptions
and repurchases, shareholders' taxpayer identification numbers must be furnished
and certified as to their accuracy.
 
    Shareholders are urged to consult their attorneys or tax advisers regarding
specific questions as to federal, state or local taxes.
 
PERFORMANCE INFORMATION
- --------------------------------------------------------------------------------
 
   
    As discussed in the Prospectus, from time to time the Fund may quote its
"yield" and/or its "total return" in advertisements and sales literature. These
figures are computed separately for Class A, Class B, Class C and Class D
shares. Yield is calculated for any 30-day period as follows: the amount of
interest income for each security in the Fund's portfolio is determined in
accordance with regulatory requirements; the total for the entire portfolio
constitutes the Fund's gross income for the period. Expenses accrued during the
period are subtracted to arrive at "net investment income" of each Class. The
resulting amount is divided by the product of the maximum offering price per
share on the last day of the period multiplied by the average number of shares
of the applicable Class outstanding during the period that were entitled to
dividends. This amount is added to 1 and raised to the sixth power. 1 is then
subtracted from the result and the difference is multiplied by 2 to arrive at
the annualized yield. For the 30-day period ended September 30, 1996, the Fund's
yield, calculated pursuant to the formula described above, was 4.99%. This yield
is for Class B only; there were no other Classes of shares outstanding on such
date.
    
 
   
    The Fund's "average annual total return" represents an annualization of the
Fund's total return over a particular period and is computed by finding the
annual percentage rate which will result in the ending redeemable value of a
hypothetical $1,000 investment made at the beginning of a one, five or ten year
period, or for the period from the date of commencement of the Fund's
operations, if shorter than any of the foregoing. The ending redeemable value is
reduced by any CDSC at the end of the one, five or ten year or other period. For
the purpose of this calculation, it is assumed that all dividends and
distributions are reinvested. The formula for computing the average annual total
return involves a percentage obtained by dividing the ending redeemable value by
the amount of the initial investment, taking a root of the quotient (where the
root is equivalent to the number of years in the period) and subtracting 1 from
the result. The average annual total return of the Fund for the fiscal year
ended September 30, 1996, for the five years ended September 30, 1996 and for
the ten years ended September 30, 1996 was 9.70%, 12.01% and 7.31%,
respectively. These returns are for Class B only; there were no other Classes of
shares outstanding on such date.
    
 
   
    In addition to the foregoing, the Fund may advertise its total return for
each Class over different periods of time by means of aggregate, average,
year-by-year or other types of total return figures. Such calculations may or
may not reflect the imposition of the maximum front-end sales charge for Class A
or the deduction of the CDSC for each of Class B and Class C which, if
reflected, would reduce the performance quoted. For example, the average annual
total return of the Fund may be calculated in the manner described above, but
without deduction for any applicable contingent deferred sales charge. Based on
this calculation, the average annual total return of the Fund for the fiscal
year ended September 30, 1996, for the five years ended September 30, 1996 and
for the ten years ended September 30, 1996 was 14.70%, 12.27% and 7.31%,
respectively. These returns are for Class B only; there were no other Classes of
shares outstanding on such date.
    
 
   
    In addition, the Fund may compute its aggregate total return for each Class
for specified periods by determining the aggregate percentage rate which will
result in the ending value of a hypothetical $1,000 investment made at the
beginning of the period. For the purpose of this calculation, it is assumed that
all dividends and distributions are reinvested. The formula for computing
aggregate total return involves a
    
 
                                       40
<PAGE>
   
percentage obtained by dividing the ending value (without the reduction for any
sales charge) by the initial $1,000 investment and subtracting 1 from the
result. Based on the foregoing calculation, the Fund's total return for the
fiscal year ended September 30, 1996, for the five years ended September 30,
1996 and for the ten years ended September 30, 1996 was 14.70%, 78.33% and
102.49%, respectively. These returns are for Class B only; there were no other
Classes of shares outstanding on such date.
    
 
   
    The Fund may also advertise the growth of hypothetical investments of
$10,000, $50,000 and $100,000 in each Class of shares of the Fund by adding 1 to
the Fund's aggregate total return to date (expressed as a decimal and without
taking into account the extent of any applicable CDSC) and multiplying by
$9,475, $48,000 and $97,000 in the case of Class A (investments of $10,000,
$50,000 and $100,000 adjusted for the initial sales charge) or by $10,000,
$50,000 and $100,000 in the case of each of Class B, Class C and Class D, as the
case may be. Investments of $10,000, $50,000 or $100,000 in the Fund at
inception would have grown to $24,281, $121,405 and $242,810, respectively, at
September 30, 1996. This information is for Class B only; there were no other
Classes of shares outstanding on such date.
    
 
    The Fund may advertise, from time to time, its performance relative to
certain performance rankings and indices compiled by independent organizations.
 
DESCRIPTION OF SHARES OF THE FUND
- --------------------------------------------------------------------------------
 
   
    As discussed in the Prospectus, the shareholders of the Fund are entitled to
a full vote for each full share held. All of the Trustees have been elected by
the shareholders of the Fund, most recently at a Special Meeting of Shareholders
held on May 21, 1997. On that date, Wayne E. Hedien was also elected as a
Trustee of the Fund, with his term to commence on September 1, 1997. The
Trustees themselves have the power to alter the number and the terms of office
of the Trustees, and they may at any time lengthen or shorten their own terms or
make their terms of unlimited duration and appoint their own successors,
provided that always at least a majority of the Trustees has been elected by the
shareholders of the Fund. Under certain circumstances, the Trustees may be
removed by action of the Trustees. The shareholders also have the right, under
certain circumstances, to remove the Trustees. The voting rights of shareholders
are not cumulative, so that holders of more than 50 percent of the shares voting
can, if they choose, elect all Trustees being selected, while the holders of the
remaining shares would be unable to elect any Trustees.
    
 
   
    The Declaration of Trust permits the Trustees to authorize the creation of
additional series of shares (the proceeds of which would be invested in
separate, independently managed portfolios) and additional classes of shares
within any series. The Trustees have not authorized any such additional series
or classes of shares other than as set forth in the Prospectus.
    
 
    The Declaration of Trust further provides that no Trustee, officer, employee
or agent of the Fund is liable to the Fund or to a shareholder, nor is any
Trustee, officer, employee or agent liable to any third persons in connection
with the affairs of the Fund, except as such liability may a rise from his/her
or its own bad faith, willful misfeasance, gross negligence, or reckless
disregard of his duties. It also provides that all third persons shall look
solely to the Fund property for satisfaction of claims arising in connection
with the affairs of the Fund. With the exceptions stated, the Declaration of
Trust provides that a Trustee, officer, employee or agent is entitled to be
indemnified against all liability in connection with the affairs of the Fund.
 
    The Fund is authorized to issue an unlimited number of shares of beneficial
interest. The Trust shall be of unlimited duration, subject to the provisions in
the Declaration of Trust concerning termination by action of the shareholders or
the Trustees.
 
                                       41
<PAGE>
CUSTODIAN AND TRANSFER AGENT
- --------------------------------------------------------------------------------
 
    The Bank of New York, 90 Washington Street, New York, New York 10286 is the
Custodian of the Fund's assets. Any of the Fund's cash balances with the
Custodian in excess of $100,000 are unprotected by federal deposit insurance.
Such balances may, at times, be substantial.
 
    Dean Witter Trust Company, Harborside Financial Center, Plaza Two, Jersey
City, New Jersey 07311 is the Transfer Agent of the Fund's shares and Dividend
Disbursing Agent for payment of dividends and distributions on Fund shares and
Agent for shareholders under various investment plans described herein. Dean
Witter Trust Company is an affiliate of Dean Witter InterCapital Inc., the
Fund's Investment Manager and Dean Witter Distributors Inc., the Fund's
Distributor. As Transfer Agent and Dividend Disbursing Agent, Dean Witter Trust
Company's responsibilities include maintaining shareholder accounts; including
providing subaccounting and recordkeeping services for certain retirement
accounts; disbursing cash dividends and reinvesting dividends; processing
account registration changes; handling purchase and redemption transactions;
mailing prospectuses and reports; mailing and tabulating proxies; processing
share certificate transactions; and maintaining shareholder records and lists.
For these services Dean Witter Trust Company receives a per shareholder account
fee from the Fund.
 
INDEPENDENT ACCOUNTANTS
- --------------------------------------------------------------------------------
 
    Price Waterhouse LLP serves as the independent accountants of the Fund. The
independent accountants are responsible for auditing the annual financial
statements of the Fund.
 
REPORTS TO SHAREHOLDERS
- --------------------------------------------------------------------------------
 
    The Fund will send to shareholders, at least semi-annually, reports showing
the Fund's portfolio and other information. An annual report, containing
financial statements audited by independent accountants, will be sent to
shareholders each year.
 
    The Fund's fiscal year ends on September 30. The financial statements of the
Fund must be audited at least once a year by independent accountants whose
selection is made annually by the Fund's Trustees.
 
   
LEGAL COUNSEL
    
- --------------------------------------------------------------------------------
 
   
    Barry Fink, Esq., who is an officer and the General Counsel of the
Investment Manager, is an officer and the General Counsel of the Fund.
    
 
EXPERTS
- --------------------------------------------------------------------------------
 
    The annual financial statements of the Fund included in this Statement of
Additional Information and incorporated by reference in the Prospectus have been
so included and incorporated in reliance on the report of Price Waterhouse LLP,
independent accountants, given on the authority of said firm as experts in
auditing and accounting.
 
REGISTRATION STATEMENT
- --------------------------------------------------------------------------------
 
    This Statement of Additional Information and the Prospectus do not contain
all of the information set forth in the Registration Statement the Fund has
filed with the Securities and Exchange Commission. The complete Registration
Statement may be obtained from the Securities and Exchange Commission upon
payment of the fee prescribed by the rules and regulations of the Commission.
 
                                       42
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
REPORT OF INDEPENDENT ACCOUNTANTS
 
TO THE SHAREHOLDERS AND TRUSTEES
OF DEAN WITTER CONVERTIBLE SECURITIES TRUST
 
In our opinion, the accompanying statement of assets and liabilities, including
the portfolio of investments, and the related statements of operations and of
changes in net assets and the financial highlights present fairly, in all
material respects, the financial position of Dean Witter Convertible Securities
Trust, (the "Fund") at September 30, 1996, the results of its operations for the
year then ended, the changes in its net assets for each of the two years in the
period then ended and the financial highlights for each of the ten years in the
period then ended, in conformity with generally accepted accounting principles.
These financial statements and financial highlights (hereafter referred to as
"financial statements") are the responsibility of the Fund's management; our
responsibility is to express an opinion on these financial statements based on
our audits. We conducted our audits of these financial statements in accordance
with generally accepted auditing standards which require that we plan and
perform the audit to obtain reasonable assurance about whether the financial
statements are free of material misstatement. An audit includes examining, on a
test basis, evidence supporting the amounts and disclosures in the financial
statements, assessing the accounting principles used and significant estimates
made by management, and evaluating the overall financial statement presentation.
We believe that our audits, which included confirmation of securities at
September 30, 1996, by correspondence with the custodian and brokers, provide a
reasonable basis for the opinion expressed above.
 
PRICE WATERHOUSE LLP
1177 AVENUE OF THE AMERICAS
NEW YORK, NEW YORK 10036
NOVEMBER 8, 1996
 
                      1996 FEDERAL TAX NOTICE (UNAUDITED)
 
       During the fiscal year ended September 30, 1996, 21.74% of the
       income dividends qualified for dividends received deduction
       available to corporations.
 
                                       43
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS SEPTEMBER 30, 1996
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                           <C>          <C>         <C>
             CORPORATE BONDS (59.4%)
             CONVERTIBLE BONDS (58.7%)
             AUTO PARTS (0.1%)
 $     190   Magna International, Inc. (Canada)..........      5.00  %    10/15/02  $       202,918
                                                                                    ---------------
             BANKING (0.2%)
       340   Banco de Galicia y Buenos Aires S.A.
               (Argentina)...............................      7.00       08/01/02          335,288
       130   Bangkok Bank Public Co. (Hong Kong).........      3.25       03/03/04          144,300
                                                                                    ---------------
                                                                                            479,588
                                                                                    ---------------
             BIOTECHNOLOGY (0.9%)
     2,050   Nabi, Inc. - 144A**.........................      6.50       02/01/03        2,207,542
                                                                                    ---------------
             BROADCAST MEDIA (0.9%)
     4,000   Jacor Communications, Inc...................      0.00       06/12/11        2,010,000
                                                                                    ---------------
             BUILDING MATERIALS (0.1%)
       220   Cemex S.A. (Mexico).........................      4.25       11/01/97          211,475
                                                                                    ---------------
             CABLE/CELLULAR (3.7%)
       210   Comcast Corp................................      3.375      09/09/05          181,463
     4,130   Comcast Corp................................      1.125      04/15/07        1,890,797
     4,000   Tele-Communications International,
               Inc.......................................      4.50       02/15/06        3,210,000
    10,270   U.S. Celluar Corp...........................      0.00       06/15/15        3,414,775
                                                                                    ---------------
                                                                                          8,697,035
                                                                                    ---------------
             CHEMICALS (2.4%)
       125   Formosa Chem & Fibre Corp. (Taiwan).........      1.75       07/19/01          131,094
    12,500   RPM, Inc....................................      0.00       09/30/12        5,546,875
                                                                                    ---------------
                                                                                          5,677,969
                                                                                    ---------------
             COMPUTER SERVICES (0.1%)
       250   Automatic Data Processing, Inc..............      0.00       02/20/12          141,442
                                                                                    ---------------
             COMPUTER SOFTWARE (0.1%)
       295   Softkey International Inc. - 144A**.........      5.50       11/01/00          236,457
                                                                                    ---------------
             CONGLOMERATES (0.9%)
     1,500   Alfa S.A. de C.V. (Mexico)..................      8.00       09/15/00        1,605,000
       300   Alfa S.A. de C.V. (Mexico) - 144A**.........      8.00       09/15/00          321,000
       100   Renong Berhad (Malaysia) - 144A**...........      2.00       07/15/05          100,750
                                                                                    ---------------
                                                                                          2,026,750
                                                                                    ---------------
             CONSTRUCTION PLANT & EQUIPMENT (0.0%)
       125   Kumagai Gumi Finance (Hong Kong)............      4.875      12/08/98          115,781
                                                                                    ---------------
             CONSUMER PRODUCTS (0.1%)
       150   President Enterprises Corp. (Taiwan)........      0.00       07/22/01          233,250
                                                                                    ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       44
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS SEPTEMBER 30, 1996, CONTINUED
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                           <C>          <C>         <C>
             DRUGS (1.4%)
 $   3,075   Bindley Western Industries, Inc.............      6.50  %    10/01/02  $     3,198,000
       240   Elan International Finance Ltd..............      0.00       10/16/12          155,954
                                                                                    ---------------
                                                                                          3,353,954
                                                                                    ---------------
             ELECTRONICS & ELECTRICAL (1.5%)
       120   Johnson Electric Holdings, Ltd. (Hong
               Kong).....................................      4.50       11/05/00          110,100
       850   Recognition Equipment Inc...................      7.25       04/15/11          791,350
     3,000   Richey Electronics Inc......................      7.00       03/01/06        2,702,670
                                                                                    ---------------
                                                                                          3,604,120
                                                                                    ---------------
             ELECTRONICS - SEMICONDUCTORS (0.1%)
        90   Integrated Device Technology................      5.50       06/01/02           71,787
       185   Xilinx Inc. - 144A**........................      5.25       11/01/02          176,486
                                                                                    ---------------
                                                                                            248,273
                                                                                    ---------------
             ENTERTAINMENT/GAMING (1.4%)
     1,353   Argosy Gaming Co............................     12.00       06/01/01        1,190,640
     2,050   Savoy Pictures Entertainment, Inc...........      7.00       07/01/03        1,476,000
       170   Technology Resources Industries Berhad
               (Malaysia)................................      2.75       11/28/04          191,250
       500   WMS Industries, Inc.........................      5.75       11/30/02          525,045
                                                                                    ---------------
                                                                                          3,382,935
                                                                                    ---------------
             FINANCIAL SERVICES (0.9%)
     2,000   AT&T Latin American Equity - 144A**.........      0.00       03/30/99        1,750,000
       175   HSH Overseas Finance Ltd. (Cayman
               Islands)..................................      5.00       01/06/01          196,437
       200   Lend Lease Finance International Ltd.
               (Australia)...............................      4.75       06/01/03          271,500
                                                                                    ---------------
                                                                                          2,217,937
                                                                                    ---------------
             FOODS (0.0%)
        80   Grand Metropolitan PLC (United Kingdom).....      6.50       01/31/00           92,700
                                                                                    ---------------
             FOREIGN GOVERNMENT (0.9%)
     2,000   Republic of Italy...........................      5.00       06/28/01        2,017,500
                                                                                    ---------------
             HEALTHCARE (8.6%)
     2,500   ARV Assisted Living, Inc. - 144A**..........      6.75       04/01/06        2,462,475
     3,450   Beverly Enterprises, Inc....................      5.50       08/01/18        3,297,613
       200   Integrated Health Services, Inc.............      5.75       01/01/01          200,478
     2,000   Integrated Health Services, Inc.............      6.00       01/01/03        1,979,680
        90   Multicare Companies, Inc....................      7.00       03/15/03          119,925
     3,155   Quantum Health Resources Inc................      4.75       10/01/00        2,918,375
     2,000   Rotech Medical Corp. - 144A**...............      5.25       06/01/03        1,725,000
     3,000   Tenet Healthcare Corp.......................      6.00       12/01/05        3,180,060
     4,000   Vivra, Inc. - 144A**........................      5.00       07/01/01        4,245,400
                                                                                    ---------------
                                                                                         20,129,006
                                                                                    ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       45
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS SEPTEMBER 30, 1996, CONTINUED
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                           <C>          <C>         <C>
             HEALTHCARE - MISCELLANEOUS (1.2%)
 $   3,800   Pharmaceutical Marketing Services, Inc......      6.25  %    02/01/03  $     2,843,502
                                                                                    ---------------
             HOME BUILDING (1.1%)
     3,015   U.S. Home Corp..............................      4.875      11/01/05        2,460,994
                                                                                    ---------------
             HOTELS/MOTELS (1.8%)
     1,000   Pailburg International Finance (Hong
               Kong).....................................      3.50       02/06/01        1,002,500
       225   Shangri-La Asia Capital (Hong Kong).........      2.875      12/16/00          188,156
     3,400   Sholodge Inc................................      7.50       05/01/04        3,076,966
                                                                                    ---------------
                                                                                          4,267,622
                                                                                    ---------------
             INDUSTRIALS (1.4%)
       120   Banpu PCL (Thailand)........................      3.50       08/25/04          144,000
       100   Sampo Corp. (Taiwan)........................      2.625      11/23/01          114,375
     2,575   Trimas Corp.................................      5.00       08/01/03        2,833,890
       100   YTL Corp. Berhad (Malaysia) - 144A**........      0.00       08/15/02          139,500
                                                                                    ---------------
                                                                                          3,231,765
                                                                                    ---------------
             INSURANCE (1.7%)
        75   Aegon NV (Netherlands) - 144A**.............      4.75       11/01/04          132,750
     3,000   CII Financial, Inc..........................      7.50       09/15/01        2,712,750
     1,000   Pioneer FinanciaI Services, Inc.............      6.50       04/01/03        1,027,700
       200   USF&G Corp..................................      0.00       03/03/09          126,750
                                                                                    ---------------
                                                                                          3,999,950
                                                                                    ---------------
             LEISURE (2.6%)
    20,995   Coleman Worldwide Corp......................      0.00       05/27/13        6,036,062
                                                                                    ---------------
             MACHINERY (1.3%)
     1,500   Cooper Industries, Inc......................      7.05       01/01/15        1,645,980
     1,500   Robbins & Meyers, Inc.......................      6.50       09/01/03        1,524,375
                                                                                    ---------------
                                                                                          3,170,355
                                                                                    ---------------
             MEDIA GROUP (2.7%)
     2,055   All American Communications Inc.............      6.50       10/01/03        2,013,900
       395   News America Holdings, Inc..................      0.00       03/11/13          177,750
     4,065   Scandinavian Broadcasting (Luxembourg)......      7.25       08/01/05        4,075,162
                                                                                    ---------------
                                                                                          6,266,812
                                                                                    ---------------
             MEDICAL PRODUCTS & SUPPLIES (0.2%)
       500   Phoenix Shannon PLC - 144A**................      9.50       11/01/00          385,625
                                                                                    ---------------
             METALS (0.4%)
     1,250   Crown Resources Corp........................      5.75       08/27/01        1,000,000
                                                                                    ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       46
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS SEPTEMBER 30, 1996, CONTINUED
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                           <C>          <C>         <C>
             OFFICE EQUIPMENT & SUPPLIES (1.8%)
 $   1,000   U.S. Office Products Co.....................      5.50  %    05/15/03  $       948,750
     3,500   U.S. Office Products Co. - 144A**...........      5.50       05/15/03        3,290,000
                                                                                    ---------------
                                                                                          4,238,750
                                                                                    ---------------
             OIL & GAS (0.1%)
       145   Apache Corp.................................      6.00       01/15/02          164,213
                                                                                    ---------------
             PAPER & FOREST PRODUCTS (0.2%)
        70   PT International Indorayon Utama
               (Indonesia)...............................      5.50       10/01/02           80,745
       120   Riverwood International Corp................      6.75       09/15/03          138,300
       350   Sappi BVI Finance Ltd. (South Africa) -
               144A**....................................      7.50       08/01/02          322,875
                                                                                    ---------------
                                                                                            541,920
                                                                                    ---------------
             POLLUTION CONTROL (0.1%)
        85   Laidlaw Inc. (Canada) - 144A**..............      6.00       01/15/99          110,118
       213   WMX Technologies, Inc.......................      2.00       01/24/05          197,157
                                                                                    ---------------
                                                                                            307,275
                                                                                    ---------------
             PUBLISHING (2.3%)
    10,000   Hollinger, Inc. (Canada)....................      0.00       10/05/13        3,337,500
        45   Nelson (Thomas), Inc. - 144A**..............      5.75       11/30/99           42,165
        90   Scholastic Corp. - 144A**...................      5.00       08/15/05          101,186
     5,000   Time Warner, Inc............................      0.00       12/17/12        1,839,250
                                                                                    ---------------
                                                                                          5,320,101
                                                                                    ---------------
             REAL ESTATE (0.3%)
        80   Guangzhou Investment Co. (Hong Kong)........      4.50       10/08/98           84,600
       200   HD Finance Cayman Ltd. (Cayman Islands) -
               144A**....................................      6.75       06/01/00          229,500
       290   New World Development (Hong Kong)...........      4.375      12/11/00          330,238
                                                                                    ---------------
                                                                                            644,338
                                                                                    ---------------
             REAL ESTATE INVESTMENT TRUST (4.2%)
     2,850   Alexander Haagen Properties, Inc. (Series
               A)........................................      7.50       01/15/01        2,597,063
     1,850   Camden Property Trust.......................      7.33       04/01/01        1,868,500
        40   Liberty Property Trust......................      8.00       07/01/01           43,500
     2,750   Mid Atlantic Realty Trust...................      7.625      09/15/03        2,586,293
     2,720   Pacific Gulf Properties Inc.................      8.375      02/15/01        2,720,000
                                                                                    ---------------
                                                                                          9,815,356
                                                                                    ---------------
             RESTAURANTS (1.2%)
     3,375   TPI Enterprises, Inc........................      8.25       07/15/02        2,868,750
                                                                                    ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       47
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS SEPTEMBER 30, 1996, CONTINUED
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                           <C>          <C>         <C>
             RETAIL (4.9%)
 $   2,000   Charming Shoppes, Inc.......................      7.50  %    07/15/06  $     2,189,340
       100   Federated Department Stores, Inc............      5.00       10/01/03          111,688
     1,750   Home Depot, Inc.............................      3.25       10/01/01        1,778,438
     3,700   Men's Wearhouse, Inc. (The).................      5.25       03/01/03        3,552,000
     3,145   Office Depot, Inc...........................      0.00       11/01/08        1,914,456
        75   Pep Boys-Manny, Moe & Jack..................      4.00       09/01/99           78,265
     2,000   Sports & Recreation Inc.....................      4.25       11/01/00        1,500,000
       275   Staples, Inc. - 144A**......................      4.50       10/01/00          315,098
                                                                                    ---------------
                                                                                         11,439,285
                                                                                    ---------------
             STEEL (2.2%)
     1,275   Nippon Denro Ltd. (India) - 144A**..........      3.00       04/01/01          605,625
     3,900   Quanex Corp.................................      6.88       06/30/07        3,948,750
       700   Sahaviriya Steel Industries (Thailand) -
               144A**....................................      3.50       07/26/05          497,000
                                                                                    ---------------
                                                                                          5,051,375
                                                                                    ---------------
             TECHNOLOGY (1.3%)
       130   EMC Corp....................................      4.25       01/01/01          155,401
     2,000   Park Electrochemical Corp...................      5.50       03/01/06        1,642,500
       150   Storage Technology Corp.....................      8.00       05/31/15          176,250
       135   Unisys Corp.................................      8.25       08/01/00          125,550
       750   Unisys Corp.................................      8.25       03/15/06          836,250
                                                                                    ---------------
                                                                                          2,935,951
                                                                                    ---------------
             TELECOMMUNICATIONS (0.8%)
       137   General Instrument Corp.....................      5.00       06/15/00          150,096
     1,750   SA Telecommunications Inc. - 144A**.........     10.00       08/15/06        1,837,500
                                                                                    ---------------
                                                                                          1,987,596
                                                                                    ---------------
             TEXTILES (0.1%)
       200   Far Eastern Textile (Taiwan)................      4.00       10/07/06          236,750
                                                                                    ---------------
             TRANSPORTATION - INTERNATIONAL (0.5%)
     1,651   Consorcio G Grupo Dina S.A. de C.V.
               (Mexico)..................................      8.00       08/08/04        1,122,680
                                                                                    ---------------
 
             TOTAL CONVERTIBLE BONDS
             (IDENTIFIED COST $138,135,816).......................................      137,623,659
                                                                                    ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       48
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS SEPTEMBER 30, 1996, CONTINUED
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                           <C>          <C>         <C>
             NON-CONVERTIBLE BONDS (0.7%)
             OIL & GAS (0.1%)
 $      70   SFP Pipeline Holdings, Inc..................     11.16  %    08/15/10  $        85,400
                                                                                    ---------------
             RESTAURANTS (0.6%)
     2,500   Flagstar Corp...............................     11.375      09/15/03        1,512,500
                                                                                    ---------------
 
             TOTAL NON-CONVERTIBLE BONDS
             (IDENTIFIED COST $2,541,700).........................................        1,597,900
                                                                                    ---------------
 
             TOTAL CORPORATE BONDS
             (IDENTIFIED COST $140,677,516).......................................      139,221,559
                                                                                    ---------------
</TABLE>
 
<TABLE>
<CAPTION>
 NUMBER OF
  SHARES                                                                                    VALUE
- ------------------------------------------------------------------------------------------------------
<C>          <S>                                                                       <C>
             CONVERTIBLE PREFERRED STOCKS (18.5%)
             AUTO PARTS (0.4%)
     1,300   Federal Mogul Corp. (Series D) $3.875 - 144A**..........................           79,300
    66,600   Mascotech, Inc. $1.20...................................................          949,050
                                                                                       ---------------
                                                                                             1,028,350
                                                                                       ---------------
             BANKS (0.8%)
    40,000   BCP International Bank, Ltd. (Series A) (Portugal) $4.00................        1,985,000
                                                                                       ---------------
             BIOTECHNOLOGY (0.4%)
    63,500   Gensia, Inc. $3.75 - 144A**.............................................        1,016,000
                                                                                       ---------------
             CABLE/CELLULAR (0.5%)
    30,000   TCI Communications, Inc. (Series A) $2.125..............................        1,196,250
                                                                                       ---------------
             CHEMICALS (0.1%)
     1,700   Occidental Petroleum Corp. $3.875 - 144A**..............................           96,475
     3,300   Occidental Petroleum Corp. (Series A) $3.00.............................          193,875
                                                                                       ---------------
                                                                                               290,350
                                                                                       ---------------
             FINANCIAL SERVICES (0.1%)
     1,700   Advanta Corp. $2.50.....................................................           72,250
     2,000   Merrill Lynch & Co., Inc. $3.12.........................................          122,000
                                                                                       ---------------
                                                                                               194,250
                                                                                       ---------------
             FOODS (0.5%)
    30,000   Chiquita Brands International, Inc. (Series A) $2.875...................        1,271,250
                                                                                       ---------------
             INSURANCE (2.0%)
    40,000   American Bankers Insurance Group, Inc. (Series B) $3.125................        2,360,000
    40,000   PennCorp Financial Group, Inc. $3.50 - 144A**...........................        2,280,000
                                                                                       ---------------
                                                                                             4,640,000
                                                                                       ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       49
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS SEPTEMBER 30, 1996, CONTINUED
 
<TABLE>
<CAPTION>
 NUMBER OF
  SHARES                                                                                    VALUE
- ------------------------------------------------------------------------------------------------------
<C>          <S>                                                                       <C>
             MEDIA GROUP (1.0%)
   240,000   Triathlon Broadcasting Co. $0.95........................................  $     2,460,000
                                                                                       ---------------
             OIL & GAS (3.0%)
   120,000   Callon Petroleum Co. (Series A) $2.125..................................        4,080,000
    40,000   ENRON Corp. $1.36.......................................................          950,000
    30,000   NorAm Financing I $3.125................................................        1,841,250
                                                                                       ---------------
                                                                                             6,871,250
                                                                                       ---------------
             PAPER & FOREST PRODUCTS (0.1%)
     2,200   International Paper Capital Trust $2.625 - 144A**.......................          105,325
                                                                                       ---------------
             POLLUTION CONTROL (0.1%)
     4,000   Browning-Ferris Industries, Inc. $2.58..................................          114,000
                                                                                       ---------------
             PUBLISHING (1.5%)
    27,000   Golden Books Financing Trust $4.375 - 144A**............................        1,520,451
   165,000   Hollinger International, Inc. $0.951....................................        1,835,625
     1,400   Houghton Mifflin Co. $4.08..............................................          135,800
                                                                                       ---------------
                                                                                             3,491,876
                                                                                       ---------------
             REAL ESTATE (0.8%)
    35,000   Catellus Development Corp. (Series B) $3.625 - 144A**...................        1,903,125
                                                                                       ---------------
             REAL ESTATE INVESTMENT TRUST (1.7%)
   151,100   FelCor Suite Hotels, Inc. (Series A) $1.95..............................        3,928,600
                                                                                       ---------------
             STEEL (1.7%)
    45,000   WHX Corp. (Series A) $3.25..............................................        1,873,125
    49,000   WHX Corp. (Series B) $3.75..............................................        2,002,875
                                                                                       ---------------
                                                                                             3,876,000
                                                                                       ---------------
             TELECOMMUNICATIONS (2.2%)
    70,000   General Datacomm Industries, Inc. $2.25 - 144A**........................        1,754,410
    48,000   Globalstar Telecommunications $3.25 - 144A**............................        2,280,000
    35,000   Sprint Corp. $2.63......................................................        1,225,000
                                                                                       ---------------
                                                                                             5,259,410
                                                                                       ---------------
             TOYS (1.5%)
   575,500   Tyco Toys, Inc. (Series C) $0.413.......................................        3,596,875
                                                                                       ---------------
             WHOLESALE DISTRIBUTOR (0.1%)
     1,300   Alco Standard Corp. $5.04...............................................          118,300
                                                                                       ---------------
 
             TOTAL CONVERTIBLE PREFERRED STOCKS
             (IDENTIFIED COST $39,390,610)...........................................       43,346,211
                                                                                       ---------------
 
             COMMON STOCKS (7.3%)
             AIR TRANSPORT (0.1%)
     2,345   Delta Air Lines, Inc....................................................          168,840
                                                                                       ---------------
             AUTO PARTS (0.5%)
    79,200   Mascotech, Inc..........................................................        1,128,600
                                                                                       ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       50
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS SEPTEMBER 30, 1996, CONTINUED
 
<TABLE>
<CAPTION>
 NUMBER OF
  SHARES                                                                                    VALUE
- ------------------------------------------------------------------------------------------------------
<C>          <S>                                                                       <C>
             CABLE/CELLULAR (0.2%)
    40,000   Centennial Cellular Corp................................................  $       530,000
                                                                                       ---------------
             DRUGS (0.1%)
    20,000   Bindley Western Industries, Inc.........................................          350,000
                                                                                       ---------------
             ENTERTAINMENT/GAMING (1.4%)
   861,328   Alliance Gaming Corp....................................................        3,229,980
                                                                                       ---------------
             HEALTHCARE (0.5%)
    50,000   Integrated Health Services, Inc.........................................        1,262,500
                                                                                       ---------------
             MANUFACTURING (0.1%)
     4,982   Fisher Scientific International, Inc....................................          205,508
                                                                                       ---------------
             MEDICAL PRODUCTS & SUPPLIES (0.5%)
    60,000   Neuromedical Systems, Inc.*.............................................        1,117,500
                                                                                       ---------------
             POLLUTION CONTROL (0.4%)
   122,000   OHM Corp.*..............................................................          960,750
                                                                                       ---------------
             REAL ESTATE INVESTMENT TRUST (1.7%)
    75,000   American General Hospitality Corp.......................................        1,425,000
    48,100   Avalon Properties, Inc..................................................        1,118,325
    30,000   Cali Realty Corp........................................................          813,750
    16,400   Urban Shopping Centers, Inc.............................................          399,750
                                                                                       ---------------
                                                                                             3,756,825
                                                                                       ---------------
             RESTAURANTS (0.7%)
   100,000   Brinker International, Inc.*............................................        1,700,000
                                                                                       ---------------
             RETAIL (0.2%)
    35,000   Michaels Stores, Inc.*..................................................          507,500
                                                                                       ---------------
             TELECOMMUNICATIONS (0.6%)
    30,000   BCE, Inc. (Canada)......................................................        1,282,500
     6,231   General Instrument Corp.*...............................................          154,217
                                                                                       ---------------
                                                                                             1,436,717
                                                                                       ---------------
             TRANSPORTATION (0.3%)
    40,000   Team Rental Group, Inc.*................................................          730,000
                                                                                       ---------------
 
             TOTAL COMMON STOCKS
             (IDENTIFIED COST $16,332,011)...........................................       17,084,720
                                                                                       ---------------
</TABLE>
 
<TABLE>
<CAPTION>
 NUMBER OF                                                              EXPIRATION
 WARRANTS                                                                  DATE           VALUE
- ----------------------------------------------------------------------------------------------------
<C>          <S>                                                        <C>          <C>
             WARRANT (0.0%)
             TELECOMMUNICATIONS
    45,000   Audiovox Corp.* - 144A** (Identified Cost $0)............     03/15/01           56,250
                                                                                     ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       51
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS SEPTEMBER 30, 1996, CONTINUED
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                           <C>          <C>         <C>
             SHORT-TERM INVESTMENTS (10.5%)
             COMMERCIAL PAPER (a) (5.5%)
             AUTOMOTIVE - FINANCE (1.7%)
 $   3,900   Ford Motor Credit Co........................      5.31  %  10/03/96..  $     3,898,849
                                                                                    ---------------
             CHEMICALS (1.7%)
     4,000   Du Pont (E.I.) de Nemours & Co., Inc........      5.388    10/04/96..        3,998,207
                                                                                    ---------------
             ENTERTAINMENT (2.1%)
     5,000   Walt Disney Co..............................      5.05     10/01/96..        5,000,000
                                                                                    ---------------
 
             TOTAL COMMERCIAL PAPER
             (AMORTIZED COST $12,897,056).........................................       12,897,056
                                                                                    ---------------
 
             REPURCHASE AGREEMENT (5.0%)
    11,682   The Bank of New York (dated 09/30/96;
               proceeds $11,684,007; collateralized by
               $11,670,451 U.S. Treasury Note 5.625% due
               10/31/97 valued at $11,916,032)
               (Identified Cost $11,682,384).............      5.00     10/01/96..       11,682,384
                                                                                    ---------------
 
             TOTAL SHORT-TERM INVESTMENTS
             (IDENTIFIED COST $24,579,440)........................................       24,579,440
                                                                                    ---------------
 
TOTAL INVESTMENTS
(IDENTIFIED COST $220,979,577) (B)..........................................   95.7%    224,288,180
 
CASH AND OTHER ASSETS IN EXCESS OF LIABILITIES..............................    4.3      10,046,026
                                                                              ------   ------------
 
NET ASSETS..................................................................  100.0%   $234,334,206
                                                                              ------   ------------
                                                                              ------   ------------
 
<FN>
- ---------------------
 *   Non-income producing security.
**   Resale is restricted to qualified institutional investors.
(a)  Securities were purchased on a discount basis. The interest rates shown
     have been adjusted to reflect a money market equivalent yield.
(b)  The aggregate cost for federal income tax purposes approximates identified
     cost. The aggregate gross unrealized appreciation was $11,991,694 and the
     aggregate gross unrealized depreciation was $8,683,091, resulting in net
     unrealized appreciation of $3,308,603.
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       52
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
FINANCIAL STATEMENTS
 
STATEMENT OF ASSETS AND LIABILITIES
SEPTEMBER 30, 1996
 
<TABLE>
<S>                                                           <C>
ASSETS:
Investments in securities, at value
  (identified cost $220,979,577)............................  $ 224,288,180
Cash........................................................      9,812,251
Receivable for:
    Interest................................................      1,823,016
    Investments sold........................................        641,875
    Shares of beneficial interest sold......................        468,023
    Dividends...............................................        295,102
Prepaid expenses............................................         39,148
                                                              -------------
 
     TOTAL ASSETS...........................................    237,367,595
                                                              -------------
 
LIABILITIES:
Payable for:
    Investments purchased...................................      1,750,000
    Shares of beneficial interest repurchased...............        727,233
    Plan of distribution fee................................        190,520
    Investment management fee...............................        114,312
    Dividends to shareholders...............................        107,695
Accrued expenses............................................        143,629
                                                              -------------
 
     TOTAL LIABILITIES......................................      3,033,389
                                                              -------------
 
NET ASSETS:
Paid-in-capital.............................................    582,151,590
Net unrealized appreciation.................................      3,308,603
Accumulated undistributed net investment income.............      4,914,784
Accumulated net realized loss...............................   (356,040,771)
                                                              -------------
 
     NET ASSETS.............................................  $ 234,334,206
                                                              -------------
                                                              -------------
 
NET ASSET VALUE PER SHARE,
  18,422,346 SHARES OUTSTANDING (UNLIMITED SHARES AUTHORIZED
  OF $.01 PAR VALUE)........................................
                                                                     $12.72
                                                              -------------
                                                              -------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       53
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
FINANCIAL STATEMENTS, CONTINUED
 
STATEMENT OF OPERATIONS
FOR THE YEAR ENDED SEPTEMBER 30, 1996
 
<TABLE>
<S>                                                           <C>
NET INVESTMENT INCOME:
 
INCOME
Interest....................................................  $10,804,205
Dividends (net of $8,958 foreign withholding tax)...........    2,916,746
                                                              -----------
 
     TOTAL INCOME...........................................   13,720,951
                                                              -----------
 
EXPENSES
Plan of distribution fee....................................    2,057,104
Investment management fee...................................    1,234,262
Transfer agent fees and expenses............................      373,604
Professional fees...........................................       81,464
Shareholder reports and notices.............................       53,986
Custodian fees..............................................       27,197
Registration fees...........................................       24,311
Trustees' fees and expenses.................................       16,451
Other.......................................................       18,564
                                                              -----------
 
     TOTAL EXPENSES.........................................    3,886,943
                                                              -----------
 
     NET INVESTMENT INCOME..................................    9,834,008
                                                              -----------
 
NET REALIZED AND UNREALIZED GAIN:
Net realized gain...........................................   13,199,408
Net change in unrealized appreciation.......................    5,765,842
                                                              -----------
 
     NET GAIN...............................................   18,965,250
                                                              -----------
 
NET INCREASE................................................  $28,799,258
                                                              -----------
                                                              -----------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       54
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
FINANCIAL STATEMENTS, CONTINUED
 
STATEMENT OF CHANGES IN NET ASSETS
 
<TABLE>
<CAPTION>
                                                              FOR THE YEAR ENDED   FOR THE YEAR ENDED
                                                              SEPTEMBER 30, 1996   SEPTEMBER 30, 1995
- -----------------------------------------------------------------------------------------------------
<S>                                                           <C>                  <C>
 
INCREASE (DECREASE) IN NET ASSETS:
 
OPERATIONS:
Net investment income.......................................     $  9,834,008         $  9,380,335
Net realized gain...........................................       13,199,408           10,976,243
Net change in unrealized appreciation.......................        5,765,842            2,262,729
                                                              ------------------   ------------------
 
     NET INCREASE...........................................       28,799,258           22,619,307
 
Dividends from net investment income........................      (10,327,902)          (8,166,179)
Net increase (decrease) from transactions in shares of
  beneficial interest.......................................       30,464,485          (19,449,807)
                                                              ------------------   ------------------
 
     TOTAL INCREASE (DECREASE)..............................       48,935,841           (4,996,679)
 
NET ASSETS:
Beginning of period.........................................      185,398,365          190,395,044
                                                              ------------------   ------------------
 
     END OF PERIOD
     (INCLUDING UNDISTRIBUTED NET INVESTMENT INCOME OF
     $4,914,784 AND $5,408,228, RESPECTIVELY)...............     $234,334,206         $185,398,365
                                                              ------------------   ------------------
                                                              ------------------   ------------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       55
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS SEPTEMBER 30, 1996
 
1. ORGANIZATION AND ACCOUNTING POLICIES
 
Dean Witter Convertible Securities Trust (the "Fund") is registered under the
Investment Company Act of 1940, as amended (the "Act"), as a diversified,
open-end management investment company. The Fund's investment objective is to
seek a high level of total return on its assets through a combination of current
income and capital appreciation. The Fund was organized as a Massachusetts
business trust on May 21, 1985 and commenced operations on October 31, 1985.
 
The preparation of financial statements in accordance with generally accepted
accounting principles requires management to make estimates and assumptions that
affect the reported amounts and disclosures. Actual results could differ from
those estimates. The following is a summary of significant accounting policies:
 
A. VALUATION OF INVESTMENTS -- (1) an equity security listed or traded on the
New York or American Stock Exchange or other domestic or foreign exchange is
valued at its latest sale price on that exchange prior to the time when assets
are valued; if there were no sales that day, the security is valued at the
latest bid price (in cases where a security is traded on more than one exchange,
the security is valued on the exchange designated as the primary market by the
Trustees); (2) all other portfolio securities for which over-the-counter market
quotations are readily available are valued at the latest available bid price
prior to the time of valuation; (3) when market quotations are not readily
available, including circumstances under which it is determined by the
Investment Manager that sale and bid prices are not reflective of a security's
market value, portfolio securities are valued at their fair value as determined
in good faith under procedures established by and under the general supervision
of the Trustees; (4) certain portfolio securities may be valued by an outside
pricing service approved by the Trustees. The pricing service utilizes a matrix
system incorporating security quality, maturity and coupon as the evaluation
model parameters, and/or research and evaluations by its staff, including review
of broker-dealer market price quotations, if available, in determining what it
believes is the fair valuation of the portfolio securities valued by such
pricing service; and (5) short-term debt securities having a maturity date of
more than sixty days at time of purchase are valued on a mark-to-market basis
until sixty days prior to maturity and thereafter at amortized cost based on
their value on the 61st day. Short-term debt securities having a maturity date
of sixty days or less at the time of purchase are valued at amortized cost.
 
B. ACCOUNTING FOR INVESTMENTS -- Security transactions are accounted for on the
trade date (date the order to buy or sell is executed). Realized gains and
losses on security transactions are determined by the identified cost method.
Discounts are accreted over the life of the respective securities. Dividend
income is recorded on the ex-dividend date. Interest income is accrued daily.
 
                                       56
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS SEPTEMBER 30, 1996, CONTINUED
 
C. FEDERAL INCOME TAX STATUS -- It is the Fund's policy to comply with the
requirements of the Internal Revenue Code applicable to regulated investment
companies and to distribute all of its taxable income to its shareholders.
Accordingly, no federal income tax provision is required.
 
D. DIVIDENDS AND DISTRIBUTIONS TO SHAREHOLDERS -- The Fund records dividends and
distributions to its shareholders on the record date. The amount of dividends
and distributions from net investment income and net realized capital gains are
determined in accordance with federal income tax regulations which may differ
from generally accepted accounting principles. These "book/tax" differences are
either considered temporary or permanent in nature. To the extent these
differences are permanent in nature, such amounts are reclassified within the
capital accounts based on their federal tax-basis treatment; temporary
differences do not require reclassification. Dividends and distributions which
exceed net investment income and net realized capital gains for financial
reporting purposes but not for tax purposes are reported as dividends in excess
of net investment income or distributions in excess of net realized capital
gains. To the extent they exceed net investment income and net realized capital
gains for tax purposes, they are reported as distributions of paid-in-capital.
 
2. INVESTMENT MANAGEMENT AGREEMENT
 
Pursuant to an Investment Management Agreement with Dean Witter InterCapital
Inc. (the "Investment Manager"), the Fund pays the Investment Manager a
management fee, accrued daily and payable monthly, by applying the following
annual rates to the Fund's net assets determined as of the close of each
business day: 0.60% to the portion of daily net assets not exceeding $750
million; 0.55% to the portion of daily net assets exceeding $750 million but not
exceeding $1 billion; 0.50% to the portion of daily net assets exceeding $1
billion but not exceeding $1.5 billion; 0.475% to the portion of daily net
assets exceeding $1.5 billion but not exceeding $2 billion; 0.45% to the portion
of daily net assets exceeding $2 billion but not exceeding $3 billion; and
0.425% to the portion of daily net assets exceeding $3 billion.
 
Under the terms of the Agreement, in addition to managing the Fund's
investments, the Investment Manager maintains certain of the Fund's books and
records and furnishes, at its own expense, office space, facilities, equipment,
clerical, bookkeeping and certain legal services and pays the salaries of all
personnel, including officers of the Fund who are employees of the Investment
Manager. The Investment Manager also bears the cost of telephone services, heat,
light, power and other utilities provided to the Fund.
 
                                       57
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS SEPTEMBER 30, 1996, CONTINUED
 
3. PLAN OF DISTRIBUTION
 
Shares of the Fund are distributed by Dean Witter Distributors Inc. (the
"Distributor"), an affiliate of the Investment Manager. The Fund has adopted a
Plan of Distribution (the "Plan") pursuant to Rule 12b-1 under the Act pursuant
to which the Fund pays the Distributor compensation, accrued daily and payable
monthly, at an annual rate of 1.0% of the lesser of: (a) the average daily
aggregate gross sales of the Fund's shares since the Fund's inception (not
including reinvestment of dividend or capital gain distributions) less the
average daily aggregate net asset value of the Fund's shares redeemed since the
Fund's inception upon which a contingent deferred sales charge has been imposed
or upon which such charge has been waived; or (b) the Fund's average daily net
assets. Amounts paid under the Plan are paid to the Distributor to compensate it
for the services provided and the expenses borne by it and others in the
distribution of the Fund's shares, including the payment of commissions for
sales of the Fund's shares and incentive compensation to, and expenses of, the
account executives of Dean Witter Reynolds Inc. ("DWR"), an affiliate of the
Investment Manager and Distributor, and other employees or selected
broker-dealers who engage in or support distribution of the Fund's shares or who
service shareholder accounts, including overhead and telephone expenses,
printing and distribution of prospectuses and reports used in connection with
the offering of the Fund's shares to other than current shareholders and
preparation, printing and distribution of sales literature and advertising
materials. In addition, the Distributor may be compensated under the Plan for
its opportunity costs in advancing such amounts, which compensation would be in
the form of a carrying charge on any unreimbursed expenses incurred by the
Distributor.
 
Provided that the Plan continues in effect, any cumulative expenses incurred but
not yet recovered may be recovered through future distribution fees from the
Fund and contingent deferred sales charges from the Fund's shareholders.
 
Although there is no legal obligation for the Fund to pay expenses incurred in
excess of payments made to the Distributor under the Plan and the proceeds of
contingent deferred sales charges paid by the investors upon redemption of
shares, if for any reason the Plan is terminated, the Trustees will consider at
that time the manner in which to treat such expenses. The Distributor has
advised the Fund that such excess amounts, including carrying charges, totaled
$71,800,910 at September 30, 1996. Of this amount, $1,471,908 represents excess
distribution expenses of TCW/DW Global Convertible Trust, the net assets of
which were combined with those of the Fund on December 22, 1995 pursuant to an
Agreement and Plan of Reorganization.
 
                                       58
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS SEPTEMBER 30, 1996, CONTINUED
 
The Distributor has informed the Fund that for the year ended September 30,
1996, it received approximately $145,000 in contingent deferred sales charges
from certain redemptions of the Fund's shares. The Fund's shareholders pay such
charges which are not an expense of the Fund.
 
4. SECURITY TRANSACTIONS AND TRANSACTIONS WITH AFFILIATES
 
The cost of purchases and proceeds from sales of portfolio securities, excluding
short-term investments, for the year ended September 30, 1996 aggregated
$309,357,627 and $305,835,298, respectively.
 
For the same period, the Fund incurred brokerage commissions of $11,922 with DWR
for portfolio transactions executed on behalf of the Fund.
 
Dean Witter Trust Company, an affiliate of the Investment Manager and
Distributor, is the Fund's transfer agent. At September 30, 1996, the Fund had
transfer agent fees and expenses payable of approximately $30,000.
 
The Fund has an unfunded noncontributory defined benefit pension plan covering
all independent Trustees of the Fund who will have served as independent
Trustees for at least five years at the time of retirement. Benefits under this
plan are based on years of service and compensation during the last five years
of service. Aggregate pension costs for the year ended September 30, 1996
included in Trustees' fees and expenses in the Statement of Operations amounted
to $1,286. At September 30, 1996, the Fund had an accrued pension liability of
$49,151 which is included in accrued expenses in the Statement of Assets and
Liabilities.
 
5. SHARES OF BENEFICIAL INTEREST
 
Transactions in shares of beneficial interest were as follows:
 
<TABLE>
<CAPTION>
                                                                           FOR THE YEAR                  FOR THE YEAR
                                                                              ENDED                         ENDED
                                                                        SEPTEMBER 30, 1996            SEPTEMBER 30, 1995
                                                                   ----------------------------   --------------------------
                                                                     SHARES          AMOUNT         SHARES         AMOUNT
                                                                   -----------   --------------   -----------   ------------
<S>                                                                <C>           <C>              <C>           <C>
Sold.............................................................    6,348,274   $   78,466,531     2,692,941   $ 29,337,865
Reinvestment of dividends........................................      715,417        8,632,934       648,602      6,920,932
Shares issued in connection with the acquisition of TCW/DW Global
 Convertible Trust (Note 6)......................................    1,665,682       19,179,898       --             --
                                                                   -----------   --------------   -----------   ------------
                                                                     8,729,373      106,279,363     3,341,543     36,258,797
Repurchased......................................................   (6,193,018)     (75,814,878)   (5,171,631)   (55,708,604)
                                                                   -----------   --------------   -----------   ------------
Net increase (decrease)..........................................    2,536,355   $   30,464,485    (1,830,088)  $(19,449,807)
                                                                   -----------   --------------   -----------   ------------
                                                                   -----------   --------------   -----------   ------------
</TABLE>
 
                                       59
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS SEPTEMBER 30, 1996, CONTINUED
 
6. ACQUISITION OF TCW/DW GLOBAL CONVERTIBLE TRUST
 
As of the close of business on December 22, 1995, the Fund acquired all the net
assets of TCW/DW Global Convertible Trust ("Global Convertible") pursuant to a
plan of reorganization approved by the shareholders of Global Convertible on
December 19, 1995. The acquisition was accomplished by a tax-free exchange of
1,665,682 shares of the Fund at a net asset value of $11.52 for 1,811,960 shares
of Global Convertible. The net assets of the Fund and Global Convertible
immediately before the acquisition were $181,407,832 and $19,179,898,
respectively, including unrealized depreciation of $1,047,150 and distributions
in excess of net realized gains of $4,600. Immediately after the acquisition,
the combined net assets of the Fund amounted to $200,587,730.
 
7. FEDERAL INCOME TAX STATUS
 
During the year ended September 30, 1996, the Fund utilized approximately
$15,672,000 of its net capital loss carryover. At September 30, 1996, the Fund
had a net capital loss carryover of approximately $352,695,000 to offset future
capital gains to the extent provided by regulations through September 30 of the
following years:
 
<TABLE>
<CAPTION>
            AMOUNTS IN THOUSANDS
- ---------------------------------------------
  1997     1998     1999     2000     TOTAL
- --------  -------  -------  -------  --------
<S>       <C>      <C>      <C>      <C>
$207,480  $36,349  $46,135  $62,731  $352,695
- --------  -------  -------  -------  --------
- --------  -------  -------  -------  --------
</TABLE>
 
Capital losses incurred after October 31 ("post-October" losses) within the
taxable year are deemed to arise on the first business day of the Fund's next
taxable year. The Fund incurred and will elect to defer net capital losses of
approximately $2,373,000 during fiscal 1996.
 
As of September 30, 1996, the Fund had temporary book/tax differences primarily
attributable to post-October losses and capital loss deferrals on wash sales.
 
                                       60
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
FINANCIAL HIGHLIGHTS
 
Selected ratios and per share data for a share of beneficial interest
outstanding throughout each period:
 
<TABLE>
<CAPTION>
                                                                 FOR THE YEAR ENDED SEPTEMBER 30
                                -------------------------------------------------------------------------------------------------
                                 1996      1995      1994      1993      1992      1991      1990      1989      1988      1987
- ---------------------------------------------------------------------------------------------------------------------------------
 
<S>                             <C>       <C>       <C>       <C>       <C>       <C>       <C>       <C>       <C>       <C>
PER SHARE OPERATING
PERFORMANCE:
 
Net asset value, beginning of
 period.......................  $11.67    $10.75    $10.62    $ 8.92    $ 8.67    $ 7.65    $ 9.68    $ 8.63    $12.42    $11.22
                                -------   -------   -------   -------   -------   -------   -------   -------   -------   -------
 
Net investment income.........    0.55      0.60      0.42      0.37      0.34      0.37      0.46      0.48      0.38      0.48
Net realized and unrealized
 gain (loss)..................    1.12      0.82      0.11      1.67      0.15      1.05     (2.06)     1.20     (2.87)     1.59
                                -------   -------   -------   -------   -------   -------   -------   -------   -------   -------
 
Total from investment
 operations...................    1.67      1.42      0.53      2.04      0.49      1.42     (1.60)     1.68     (2.49)     2.07
                                -------   -------   -------   -------   -------   -------   -------   -------   -------   -------
 
Less dividends and
 distributions from:
  Net investment income.......   (0.62)    (0.50)    (0.40)    (0.34)    (0.24)    (0.40)    (0.43)    (0.63)    (0.23)    (0.46)
  Net realized gain...........    --        --        --        --        --        --        --        --       (1.07)    (0.41)
                                -------   -------   -------   -------   -------   -------   -------   -------   -------   -------
 
Total dividends and
 distributions................   (0.62)    (0.50)    (0.40)    (0.34)    (0.24)    (0.40)    (0.43)    (0.63)    (1.30)    (0.87)
                                -------   -------   -------   -------   -------   -------   -------   -------   -------   -------
 
Net asset value, end of
 period.......................  $12.72    $11.67    $10.75    $10.62    $ 8.92    $ 8.67    $ 7.65    $ 9.68    $ 8.63    $12.42
                                -------   -------   -------   -------   -------   -------   -------   -------   -------   -------
                                -------   -------   -------   -------   -------   -------   -------   -------   -------   -------
 
TOTAL INVESTMENT RETURN+......   14.70%    13.68%     5.02%    23.22%     5.69%    18.93%   (16.93)%   20.20%   (19.79)%   19.21%
 
RATIOS TO AVERAGE NET ASSETS:
Expenses......................    1.89%     1.96%     1.93%     1.93%     1.92%     1.92%     1.88%     1.76%     1.79%     1.62%
 
Net investment income.........    4.78%     5.24%     3.68%     3.44%     3.43%     4.34%     4.96%     4.93%     3.87%     3.85%
 
SUPPLEMENTAL DATA:
Net assets, end of period, in
 millions.....................    $234      $185      $190      $208      $218      $297      $413      $822    $1,073    $2,029
 
Portfolio turnover rate.......     171%      138%      184%      221%      145%      133%       92%      167%      472%      572%
 
Average commission rate
 paid.........................  $0.0581     --        --        --        --        --        --        --        --        --
<FN>
 
- ---------------------
 +   Does not reflect the deduction of sales charge. Calculated based on the net
     asset value as of the last business day of the period.
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
 
                                       61
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS MARCH 31, 1997 (UNAUDITED)
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                          <C>           <C>         <C>
             CORPORATE BONDS (57.7%)
             CONVERTIBLE BONDS (57.7%)
             AEROSPACE & DEFENSE (0.8%)
 $   2,000   Titan Corp.................................       8.25  %    11/01/03  $     2,057,500
                                                                                    ---------------
             AUTO PARTS (1.4%)
     4,000   MascoTech, Inc.............................       4.50       12/15/03        3,610,000
                                                                                    ---------------
             BANKS - INTERNATIONAL (0.0%)
       130   Bangkok Bank Public Co. (Hong Kong)........       3.25       03/03/04          124,150
                                                                                    ---------------
             BIOTECHNOLOGY (0.3%)
     1,050   Nabi, Inc. - 144A**........................       6.50       02/01/03          871,185
                                                                                    ---------------
             BROADCAST MEDIA (1.5%)
     4,000   Jacor Communications, Inc..................       0.00       06/12/11        1,855,120
     2,065   Scandinavian Broadcasting System SA
               (Luxembourg).............................       7.25       08/01/05        1,868,825
                                                                                    ---------------
                                                                                          3,723,945
                                                                                    ---------------
             CABLE/CELLULAR (3.4%)
       210   Comcast Corp...............................       3.375      09/09/05          198,076
     4,130   Comcast Corp...............................       1.125      04/15/07        2,108,984
     4,000   Tele-Communications International, Inc.....       4.50       02/15/06        2,970,000
    10,270   U.S. Cellular Corp.........................       0.00       06/15/15        3,361,371
                                                                                    ---------------
                                                                                          8,638,431
                                                                                    ---------------
             CHEMICALS (2.2%)
    12,500   RPM Inc....................................       0.00       09/30/12        5,703,125
                                                                                    ---------------
             DRUGS (1.3%)
     3,075   Bindley Western Industries, Inc............       6.50       10/01/02        3,228,750
                                                                                    ---------------
             ELECTRONICS & ELECTRICAL (1.2%)
     3,000   Richey Electronics Inc.....................       7.00       03/01/06        3,191,250
                                                                                    ---------------
             ELECTRONICS - SEMICONDUCTORS (0.3%)
     1,000   Cirrus Logic, Inc..........................       6.00       12/15/03          768,130
        90   Integrated Device Technology...............       5.50       06/01/02           74,123
                                                                                    ---------------
                                                                                            842,253
                                                                                    ---------------
             ENGINEERING & CONSTRUCTION (0.0%)
       125   Kumagai Gumi Finance Inc. (Hong Kong)......       4.875      12/08/98          118,125
                                                                                    ---------------
             ENTERTAINMENT/GAMING (0.6%)
     2,050   Savoy Pictures Entertainment, Inc..........       7.00       07/01/03        1,660,500
                                                                                    ---------------
             ENVIRONMENTAL (1.3%)
     3,825   Thermo Terratech, Inc......................       4.625      05/01/03        3,423,375
                                                                                    ---------------
             EQUIPMENT (0.9%)
     2,225   Varlen Corp................................       6.50       06/01/03        2,247,250
                                                                                    ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       62
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                          <C>           <C>         <C>
             FINANCE - LEASING (1.1%)
 $   3,000   Leasing Solutions, Inc.....................       6.875 %    10/01/03  $     2,685,000
                                                                                    ---------------
             FINANCIAL SERVICES (3.4%)
     2,000   AT&T Latin American Equity - 144A**........       0.00       03/30/99        1,857,500
     5,000   Deutsche Bank Finance BV - 144A**
               (Netherlands)............................       0.00       02/12/17        2,160,000
     5,000   UBS Finance Delaware.......................       2.00       12/15/00        4,631,250
                                                                                    ---------------
                                                                                          8,648,750
                                                                                    ---------------
             FOREIGN GOVERNMENT (0.8%)
     2,000   Republic of Italy (Italy)..................       5.00       06/28/01        1,961,260
                                                                                    ---------------
             HEALTHCARE (11.7%)
     2,500   ARV Assisted Living, Inc. - 144A**.........       6.75       04/01/06        2,090,625
        50   Beverly Enterprises, Inc...................       5.50       08/01/18        1,062,860
     3,000   Emeritus Corp. - 144A**....................       6.25       01/01/06        2,443,140
     2,000   FPA Medical Management, Inc................       6.50       12/15/01        1,988,750
     2,200   Integrated Health Services, Inc............       5.75       01/01/01        2,297,438
     2,600   Integrated Health Services, Inc............       6.00       01/01/03        2,741,154
       500   Phoenix Shannon - 144A** (Ireland) (a).....       9.50       11/01/00               --
     5,960   Phymatrix Corp.............................       6.75       06/15/03        5,035,366
       105   Quantum Health Resources Inc...............       4.75       10/01/00           96,361
     2,000   Rotech Medical Corp........................       5.25       06/01/03        1,867,000
     2,500   Sterling House Corp........................       6.75       06/30/06        1,765,625
     3,000   Tenet Healthcare, Inc......................       6.00       12/01/05        3,447,960
     5,000   Theratx Inc................................       8.00       02/01/02        5,000,000
                                                                                    ---------------
                                                                                         29,836,279
                                                                                    ---------------
             HEALTHCARE - MISCELLANEOUS (1.2%)
     3,800   Pharmaceutical Marketing Services, Inc.....       6.25       02/01/03        2,978,250
                                                                                    ---------------
             HEATING & AIR CONDITIONING (0.8%)
     2,000   American Residential Holdings Corp. -
               144A**...................................       7.25       04/15/04        1,975,000
                                                                                    ---------------
             HOME BUILDING (1.1%)
     3,015   U.S. Home Corp.............................       4.875      11/01/05        2,749,921
                                                                                    ---------------
             HOSPITAL MANAGEMENT &
             HEALTH MAINTENANCE ORGANIZATIONS (1.1%)
     3,000   CII Financial Inc..........................       7.50       09/15/01        2,729,190
                                                                                    ---------------
             HOTELS/MOTELS (2.1%)
       225   Shangri-La Asia Capital (Hong Kong)........       2.875      12/16/00          191,531
     4,400   Sholodge Inc...............................       7.50       05/01/04        3,960,000
     1,310   Signature Resorts, Inc.....................       5.75       01/15/07        1,088,938
                                                                                    ---------------
                                                                                          5,240,469
                                                                                    ---------------
             INSURANCE (0.1%)
       200   USF&G Corp.................................       0.00       03/03/09          132,346
                                                                                    ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       63
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                          <C>           <C>         <C>
             LEISURE (0.0%)
 $     325   Coleman Worldwide Corp.....................       0.00  %    05/27/13  $        92,853
                                                                                    ---------------
             MACHINERY (0.4%)
     1,094   Cooper Industries, Inc.....................       7.05       01/01/15        1,149,772
                                                                                    ---------------
             MEDIA GROUP (0.1%)
       395   News America Holdings, Inc.................       0.00       03/11/13          168,175
                                                                                    ---------------
             MEDICAL PRODUCTS & SUPPLIES (0.9%)
     2,750   Uromed Corp. - 144A**......................       6.00       10/15/03        2,345,530
                                                                                    ---------------
             METALS & MINING (0.5%)
       120   Banpu Public Company Ltd. (Thailand).......       3.50       08/25/04          118,200
     1,250   Crown Resources Corp.......................       5.75       08/27/01        1,112,500
                                                                                    ---------------
                                                                                          1,230,700
                                                                                    ---------------
             OFFICE EQUIPMENT & SUPPLIES (2.3%)
     7,175   U.S. Office Products Co....................       5.50       05/15/03        6,000,094
                                                                                    ---------------
             POLLUTION CONTROL (0.1%)
       213   WMX Technologies, Inc......................       2.00       01/24/05          190,132
                                                                                    ---------------
             PUBLISHING (2.6%)
    13,000   Hollinger, Inc. (Canada)...................       0.00       10/05/13        4,647,500
        45   Nelson (Thomas), Inc. - 144A**.............       5.75       11/30/99           41,644
     5,000   Time Warner, Inc...........................       0.00       12/17/12        1,897,900
                                                                                    ---------------
                                                                                          6,587,044
                                                                                    ---------------
             REAL ESTATE INVESTMENT TRUST (2.3%)
     2,850   Alexander Haagen Properties, Inc. (Series
               A).......................................       7.50       01/15/01        2,657,625
     3,140   Mid Atlantic Realty Trust..................       7.625      09/15/03        3,289,527
                                                                                    ---------------
                                                                                          5,947,152
                                                                                    ---------------
             RESTAURANTS (1.3%)
     3,600   Hometown Buffet, Inc.......................       7.00       12/01/02        3,321,000
                                                                                    ---------------
             RETAIL (2.6%)
     1,750   Home Depot, Inc............................       3.25       10/01/01        1,737,645
     2,000   Jumbosports, Inc...........................       4.25       11/01/00        1,372,500
     2,000   Men's Wearhouse, Inc. (The)................       5.25       03/01/03        2,071,820
       145   Office Depot, Inc..........................       0.00       11/01/08           87,787
        75   Pep Boys - Manny, Moe & Jack, Inc..........       4.00       09/01/99           75,407
     1,500   The Sports Authority, Inc..................       5.25       09/15/01        1,358,805
                                                                                    ---------------
                                                                                          6,703,964
                                                                                    ---------------
             STEEL (1.6%)
     3,900   Quanex Corp................................       6.88       06/30/07        3,900,000
       450   Sahaviriya Steel Industries - 144A**
               (Thailand)...............................       3.50       07/26/05          283,500
                                                                                    ---------------
                                                                                          4,183,500
                                                                                    ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       64
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                          <C>           <C>         <C>
             TECHNOLOGY (3.7%)
 $   2,420   Eidos PLC - 144A** (United Kingdom)........       6.25  %    07/31/02  $     2,350,425
     1,000   HMT Technology Corp. - 144A**..............       5.75       01/15/04          841,520
     2,000   Intevac Corp - 144A***.....................       6.50       03/01/04        1,841,240
     1,500   Lernout & Hauspie Speech Products NV -
               144A** (Belgium).........................       8.00       11/15/01        1,525,800
       800   Safeguard Scientifics, Inc.................       6.00       02/01/06          686,000
       200   Safeguard Scientifics, Inc. - 144A**.......       6.00       02/01/06          174,624
     2,135   Unisys Corp................................       8.25       08/01/00        2,054,938
                                                                                    ---------------
                                                                                          9,474,547
                                                                                    ---------------
             TELECOMMUNICATIONS (0.7%)
       137   General Instrument Corp....................       5.00       06/15/00          142,443
     1,750   SA Telecommunications Inc. - 144A**........      10.00       08/15/06        1,540,000
                                                                                    ---------------
                                                                                          1,682,443
                                                                                    ---------------
 
             TOTAL CONVERTIBLE BONDS
             (IDENTIFIED COST $147,671,122).......................................      147,453,210
                                                                                    ---------------
 
             NON-CONVERTIBLE BOND (0.0%)
             OIL & GAS
        70   SFP Pipeline Holdings (Identified Cost
               $91,700).................................      11.16       08/15/10           85,050
                                                                                    ---------------
 
             TOTAL CORPORATE BONDS
             (IDENTIFIED COST $147,762,822).......................................      147,538,260
                                                                                    ---------------
</TABLE>
 
<TABLE>
<CAPTION>
 NUMBER OF
  SHARES                                                                                    VALUE
- ------------------------------------------------------------------------------------------------------
<C>          <S>                                                                       <C>
             CONVERTIBLE PREFERRED STOCKS (32.5%)
             APPAREL (1.3%)
   102,000   Designer Finance Trust $3.00............................................        3,327,750
                                                                                       ---------------
             AUTO PARTS (1.5%)
    66,600   Mascotech, Inc. $1.20...................................................        1,232,100
   100,000   Walbro Capital Trust $2.00..............................................        2,600,000
                                                                                       ---------------
                                                                                             3,832,100
                                                                                       ---------------
             BANKS - INTERNATIONAL (1.9%)
    40,000   Banco Comercial Portuguese (Series A) (Portugal) $4.00..................        2,230,000
   110,000   National Australia Bank, Ltd. (Australia) $1.969 (Units)++..............        2,750,000
                                                                                       ---------------
                                                                                             4,980,000
                                                                                       ---------------
             BIOTECHNOLOGY (0.5%)
    63,500   Gensia Inc. $3.75 - 144A**..............................................        1,162,875
                                                                                       ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       65
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
<TABLE>
<CAPTION>
 NUMBER OF
  SHARES                                                                                    VALUE
- ------------------------------------------------------------------------------------------------------
<C>          <S>                                                                       <C>
             BROADCAST MEDIA (2.5%)
   101,570   SFX Broadcasting, Inc. (Series D) $3.25.................................  $     4,354,814
   242,000   Triathlon Broadcasting Co. $0.945.......................................        1,996,500
                                                                                       ---------------
                                                                                             6,351,314
                                                                                       ---------------
             CABLE/CELLULAR (1.2%)
   215,000   Nextel Trust (STRYPES) $1.015...........................................        3,063,750
                                                                                       ---------------
             CHEMICALS (0.1%)
     1,700   Occidental Petroleum Corp. $3.875 - 144A**..............................           98,495
     3,300   Occidental Petroleum Corp. (Series A) $3.00.............................          219,450
                                                                                       ---------------
                                                                                               317,945
                                                                                       ---------------
             COMPUTER SOFTWARE (1.6%)
    51,000   Microsoft Corp. (Series A) $2.196.......................................        4,131,000
                                                                                       ---------------
             FINANCIAL SERVICES (4.1%)
   100,000   Insignia Financing, Inc. $3.25 - 144A**.................................        4,506,300
   100,000   Merrill Lynch & Co., Inc. (STRYPES) $4.087 (1)..........................        5,900,000
                                                                                       ---------------
                                                                                            10,406,300
                                                                                       ---------------
             FOODS (0.6%)
    30,000   Chiquita Brands International, Inc. (Series A) $2.875...................        1,477,500
                                                                                       ---------------
             INDUSTRIALS (1.1%)
    75,000   Elsag Bailey Process Automation (Netherlands) $2.75.....................        2,760,975
                                                                                       ---------------
             LEISURE (0.4%)
    16,800   Royal Caribbean Cruises Inc. (Series A) $3.625..........................          940,800
                                                                                       ---------------
             MACHINE TOOLS (1.6%)
   100,000   Greenfield Capital Trust, Inc. $3.00....................................        4,162,500
                                                                                       ---------------
             METALS & MINING (0.8%)
   117,900   Coeur D'Alene Mines Corp. $1.488........................................        2,092,725
                                                                                       ---------------
             OIL & GAS (2.8%)
    55,000   Callon Petroleum Co. (Series A) $2.125..................................        2,048,750
   155,000   ENRON Corp. $1.36.......................................................        3,332,500
    30,000   NorAm Financing I $3.125................................................        1,867,500
                                                                                       ---------------
                                                                                             7,248,750
                                                                                       ---------------
             PAPER PRODUCTS (1.6%)
    81,800   James River Corp. of Virginia (Series K) $3.375.........................        3,987,750
                                                                                       ---------------
             PUBLISHING (0.6%)
   165,000   Hollinger International, Inc. $0.951....................................        1,650,000
                                                                                       ---------------
             REAL ESTATE (0.7%)
    36,600   Rouse Co. (Series B) $3.00..............................................        1,793,400
                                                                                       ---------------
             REAL ESTATE INVESTMENT TRUST (3.2%)
   151,100   FelCor Suite Hotels, Inc. (Series A) $1.95..............................        4,306,350
   163,100   Wellsford Residential Property Trust (Series A) $1.75...................        3,873,625
                                                                                       ---------------
                                                                                             8,179,975
                                                                                       ---------------
             STEEL (0.6%)
    45,000   WHX Corp. (Series A) $3.25..............................................        1,620,000
                                                                                       ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       66
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
<TABLE>
<CAPTION>
 NUMBER OF
  SHARES                                                                                    VALUE
- ------------------------------------------------------------------------------------------------------
<C>          <S>                                                                       <C>
             TELECOMMUNICATIONS (3.8%)
    70,000   General Datacomm Industries, Inc. $2.25 - 144A**........................  $     1,378,160
    50,000   Globalstar Telecommunications, Ltd. $3.25...............................        2,587,500
    25,000   IXC Communication, Inc. $7.25 - 144A**+.................................        2,487,500
    40,000   Loral Space & Communications Ltd. $3.00 - 144A**........................        1,950,000
    35,000   Sprint Corp. $2.63......................................................        1,203,125
                                                                                       ---------------
                                                                                             9,606,285
 
             TOTAL CONVERTIBLE PREFERRED STOCKS
             (IDENTIFIED COST $83,505,591)...........................................       83,093,694
                                                                                       ---------------
 
             COMMON STOCKS (5.0%)
             CABLE/CELLULAR (0.2%)
    40,000   Centennial Cellular Corp. (Class A)*....................................          410,000
                                                                                       ---------------
             DRUGS (0.1%)
    20,000   Bindley Western Industries, Inc.........................................          375,000
                                                                                       ---------------
             ENTERTAINMENT/GAMING (1.2%)
   861,328   Alliance Gaming Corp.*..................................................        3,068,481
                                                                                       ---------------
             HEALTHCARE (0.6%)
    50,000   Integrated Health Services, Inc.........................................        1,462,500
                                                                                       ---------------
             MEDICAL PRODUCTS & SUPPLIES (0.2%)
    60,000   Neuromedical Systems, Inc.*.............................................          585,000
                                                                                       ---------------
             POLLUTION CONTROL (0.4%)
   122,000   OHM Corp.*..............................................................          960,750
                                                                                       ---------------
             REAL ESTATE INVESTMENT TRUST (1.8%)
    90,100   American General Hospitality Corp.......................................        2,455,225
    77,083   Camden Property Trust...................................................        2,100,512
                                                                                       ---------------
                                                                                             4,555,737
                                                                                       ---------------
             RESTAURANTS (0.5%)
   100,000   Brinker International, Inc.*............................................        1,262,500
                                                                                       ---------------
 
             TOTAL COMMON STOCKS
             (IDENTIFIED COST $12,665,720)...........................................       12,679,968
                                                                                       ---------------
 
             PREFERRED STOCKS (0.8%)
             BROADCAST MEDIA
     5,000   Chancellor Radio Broadcast, Inc. $12.00 - 144A**........................          488,125
    15,000   SFX Broadcasting, Inc. (Series E) $12.625+..............................        1,449,375
                                                                                       ---------------
 
             TOTAL PREFERRED STOCKS
             (IDENTIFIED COST $2,000,000)............................................        1,937,500
                                                                                       ---------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       67
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
PORTFOLIO OF INVESTMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
<TABLE>
<CAPTION>
 NUMBER OF                                                                  EXPIRATION
 WARRANTS                                                                      DATE
- -----------------------------------------------------------------------------------------------------
<C>          <S>                                                            <C>         <C>
             WARRANTS (0.0%)
             TELECOMMUNICATIONS
 $  45,000   Audiovox Corp.* - 144A** (Identified Cost $0)................    03/15/01  $     106,875
                                                                                        -------------
</TABLE>
 
<TABLE>
<CAPTION>
 PRINCIPAL
 AMOUNT IN                                                   COUPON      MATURITY
 THOUSANDS                                                    RATE         DATE          VALUE
- ---------------------------------------------------------------------------------------------------
<C>          <S>                                          <C>           <C>         <C>
             SHORT-TERM INVESTMENT (4.6%)
             REPURCHASE AGREEMENT
    11,785   The Bank of New York (dated 03/31/97;
               proceeds $11,786,638; collateralized by
               $12,258,828 U.S. Treasury Note 6.25% due
               02/15/03 valued at $12,020,576)
               (Identified Cost $11,784,878)............       5.375 %    04/01/97       11,784,878
                                                                                    ---------------
 
TOTAL INVESTMENTS
(IDENTIFIED COST $257,719,011) (B)...........      100.6%   257,141,175
 
LIABILITIES IN EXCESS OF OTHER ASSETS........       (0.6)    (1,509,817)
                                                   -----   ------------
 
NET ASSETS...................................      100.0%  $255,631,358
                                                   -----   ------------
                                                   -----   ------------
 
<FN>
- ---------------------
STRYPES Structured yield product exchangeable for stock.
 *   Non-income producing security.
**   Resale is restricted to qualified institutional investors.
++   Consists of one or more class of securities traded together as a unit;
     stocks with attached warrants.
 +   Payment-in-kind security.
(1)  Exchangeable for SunAmerica, Inc. common stock.
(a)  Non-income producing security; bond in default.
(b)  The aggregate cost for federal income tax purposes approximates identified
     cost. The aggregate gross unrealized appreciation is $9,406,393 and the
     aggregate gross unrealized depreciation is $9,984,229, resulting in net
     unrealized depreciation of $577,836.
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       68
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
FINANCIAL STATEMENTS
 
STATEMENT OF ASSETS AND LIABILITIES
MARCH 31, 1997 (UNAUDITED)
 
<TABLE>
<S>                                                           <C>
ASSETS:
Investments in securities, at value
  (identified cost $257,719,011)............................  $ 257,141,175
Receivable for:
    Investments sold........................................      7,179,444
    Interest................................................      2,124,424
    Shares of beneficial interest sold......................        496,047
    Dividends...............................................        150,146
Prepaid expenses and other assets...........................         65,821
                                                              -------------
 
     TOTAL ASSETS...........................................    267,157,057
                                                              -------------
 
LIABILITIES:
Payable for:
    Investments purchased...................................     10,687,115
    Shares of beneficial interest repurchased...............        222,337
    Plan of distribution fee................................        218,526
    Investment management fee...............................        131,116
    Dividends to shareholders...............................        109,111
Accrued expenses and other payables.........................        157,494
                                                              -------------
 
     TOTAL LIABILITIES......................................     11,525,699
                                                              -------------
 
NET ASSETS:
Paid-in-capital.............................................    599,139,750
Net unrealized depreciation.................................       (577,836)
Accumulated undistributed net investment income.............      4,628,090
Accumulated net realized loss...............................   (347,558,646)
                                                              -------------
 
     NET ASSETS.............................................  $ 255,631,358
                                                              -------------
                                                              -------------
 
NET ASSET VALUE PER SHARE,
  19,719,736 SHARES OUTSTANDING (UNLIMITED SHARES AUTHORIZED
  OF $.01 PAR VALUE)........................................
                                                                     $12.96
                                                              -------------
                                                              -------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       69
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
FINANCIAL STATEMENTS, CONTINUED
 
STATEMENT OF OPERATIONS
FOR THE SIX MONTHS ENDED MARCH 31, 1997 (UNAUDITED)
 
<TABLE>
<S>                                                           <C>
NET INVESTMENT INCOME:
 
INCOME
Interest....................................................  $ 5,681,253
Dividends...................................................    1,800,030
                                                              -----------
 
     TOTAL INCOME...........................................    7,481,283
                                                              -----------
 
EXPENSES
Plan of distribution fee....................................    1,224,399
Investment management fee...................................      734,639
Transfer agent fees and expenses............................      180,706
Shareholder reports and notices.............................       38,153
Professional fees...........................................       29,769
Registration fees...........................................       21,964
Custodian fees..............................................       12,886
Trustees' fees and expenses.................................        6,561
Other.......................................................        6,687
                                                              -----------
 
     TOTAL EXPENSES.........................................    2,255,764
                                                              -----------
 
     NET INVESTMENT INCOME..................................    5,225,519
                                                              -----------
 
NET REALIZED AND UNREALIZED GAIN (LOSS):
Net realized gain...........................................    8,482,125
Net change in unrealized appreciation.......................   (3,886,439)
                                                              -----------
 
     NET GAIN...............................................    4,595,686
                                                              -----------
 
NET INCREASE................................................  $ 9,821,205
                                                              -----------
                                                              -----------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       70
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
FINANCIAL STATEMENTS, CONTINUED
 
STATEMENT OF CHANGES IN NET ASSETS
 
<TABLE>
<CAPTION>
                                                              FOR THE SIX MONTHS
                                                                    ENDED             FOR THE YEAR
                                                                MARCH 31, 1997           ENDED
                                                                 (UNAUDITED)       SEPTEMBER 30, 1996
- -----------------------------------------------------------------------------------------------------
<S>                                                           <C>                  <C>
 
INCREASE (DECREASE) IN NET ASSETS:
 
OPERATIONS:
Net investment income.......................................     $  5,225,519         $  9,834,008
Net realized gain...........................................        8,482,125           13,199,408
Net change in unrealized appreciation/depreciation..........       (3,886,439)           5,765,842
                                                              ------------------   ------------------
 
     NET INCREASE...........................................        9,821,205           28,799,258
 
Dividends from net investment income........................       (5,512,213)         (10,327,902)
Net increase from transactions in shares of beneficial
  interest..................................................       16,988,160           30,464,485
                                                              ------------------   ------------------
 
     NET INCREASE...........................................       21,297,152           48,935,841
 
NET ASSETS:
Beginning of period.........................................      234,334,206          185,398,365
                                                              ------------------   ------------------
 
     END OF PERIOD
    (INCLUDING UNDISTRIBUTED NET INVESTMENT INCOME OF
    $4,628,090 AND $4,914,784, RESPECTIVELY)................     $255,631,358         $234,334,206
                                                              ------------------   ------------------
                                                              ------------------   ------------------
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
                                       71
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS MARCH 31, 1997 (UNAUDITED)
 
1. ORGANIZATION AND ACCOUNTING POLICIES
 
Dean Witter Convertible Securities Trust (the "Fund") is registered under the
Investment Company Act of 1940, as amended (the "Act"), as a diversified,
open-end management investment company. The Fund's investment objective is to
seek a high level of total return on its assets through a combination of current
income and capital appreciation. The Fund was organized as a Massachusetts
business trust on May 21, 1985 and commenced operations on October 31, 1985.
 
The preparation of financial statements in accordance with generally accepted
accounting principles requires management to make estimates and assumptions that
affect the reported amounts and disclosures. Actual results could differ from
those estimates.
 
The following is a summary of significant accounting policies:
 
A. VALUATION OF INVESTMENTS -- (1) an equity security listed or traded on the
New York, American or other domestic or foreign stock exchange is valued at its
latest sale price on that exchange prior to the time when assets are valued; if
there were no sales that day, the security is valued at the latest bid price (in
cases where a security is traded on more than one exchange, the security is
valued on the exchange designated as the primary market pursuant to procedures
adopted by the Trustees); (2) all other portfolio securities for which
over-the-counter market quotations are readily available are valued at the
latest available bid price prior to the time of valuation; (3) when market
quotations are not readily available, including circumstances under which it is
determined by Dean Witter InterCapital Inc. (the "Investment Manager") that sale
and bid prices are not reflective of a security's market value, portfolio
securities are valued at their fair value as determined in good faith under
procedures established by and under the general supervision of the Trustees; (4)
certain portfolio securities may be valued by an outside pricing service
approved by the Trustees. The pricing service may utilize a matrix system
incorporating security quality, maturity and coupon as the evaluation model
parameters, and/or research and evaluations by its staff, including review of
broker-dealer market price quotations, if available, in determining what it
believes is the fair valuation of the portfolio securities valued by such
pricing service; and (5) short-term debt securities having a maturity date of
more than sixty days at time of purchase are valued on a mark-to-market basis
until sixty days prior to maturity and thereafter at amortized cost based on
their value on the 61st day. Short-term debt securities having a maturity date
of sixty days or less at the time of purchase are valued at amortized cost.
 
B. ACCOUNTING FOR INVESTMENTS -- Security transactions are accounted for on the
trade date (date the order to buy or sell is executed). Realized gains and
losses on security transactions are determined
 
                                       72
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
by the identified cost method. Discounts are accreted over the life of the
respective securities. Dividend income is recorded on the ex-dividend date.
Interest income is accrued daily except where collection is not expected.
 
C. FEDERAL INCOME TAX STATUS -- It is the Fund's policy to comply with the
requirements of the Internal Revenue Code applicable to regulated investment
companies and to distribute all of its taxable income to its shareholders.
Accordingly, no federal income tax provision is required.
 
D. DIVIDENDS AND DISTRIBUTIONS TO SHAREHOLDERS -- The Fund records dividends and
distributions to its shareholders on the record date. The amounts of dividends
and distributions from net investment income and net realized capital gains are
determined in accordance with federal income tax regulations which may differ
from generally accepted accounting principles. These "book/tax" differences are
either considered temporary or permanent in nature. To the extent these
differences are permanent in nature, such amounts are reclassified within the
capital accounts based on their federal tax-basis treatment; temporary
differences do not require reclassification. Dividends and distributions which
exceed net investment income and net realized capital gains for financial
reporting purposes but not for tax purposes are reported as dividends in excess
of net investment income or distributions in excess of net realized capital
gains. To the extent they exceed net investment income and net realized capital
gains for tax purposes, they are reported as distributions of paid-in-capital.
 
2. INVESTMENT MANAGEMENT AGREEMENT
 
Pursuant to an Investment Management Agreement, the Fund pays the Investment
Manager a management fee, accrued daily and payable monthly, by applying the
following annual rates to the Fund's net assets determined as of the close of
each business day: 0.60% to the portion of daily net assets not exceeding $750
million; 0.55% to the portion of daily net assets exceeding $750 million but not
exceeding $1 billion; 0.50% to the portion of daily net assets exceeding $1
billion but not exceeding $1.5 billion; 0.475% to the portion of daily net
assets exceeding $1.5 billion but not exceeding $2 billion; 0.45% to the portion
of daily net assets exceeding $2 billion but not exceeding $3 billion; and
0.425% to the portion of daily net assets exceeding $3 billion.
 
Under the terms of the Agreement, in addition to managing the Fund's
investments, the Investment Manager maintains certain of the Fund's books and
records and furnishes, at its own expense, office space, facilities, equipment,
clerical, bookkeeping and certain legal services and pays the salaries of all
personnel, including officers of the Fund who are employees of the Investment
Manager. The
 
                                       73
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
Investment Manager also bears the cost of telephone services, heat, light, power
and other utilities provided to the Fund.
 
3. PLAN OF DISTRIBUTION
 
Shares of the Fund are distributed by Dean Witter Distributors Inc. (the
"Distributor"), an affiliate of the Investment Manager. The Fund has adopted a
Plan of Distribution (the "Plan") pursuant to Rule 12b-1 under the Act pursuant
to which the Fund pays the Distributor compensation, accrued daily and payable
monthly, at an annual rate of 1.0% of the lesser of: (a) the average daily
aggregate gross sales of the Fund's shares since the Fund's inception (not
including reinvestment of dividend or capital gain distributions) less the
average daily aggregate net asset value of the Fund's shares redeemed since the
Fund's inception upon which a contingent deferred sales charge has been imposed
or upon which such charge has been waived; or (b) the Fund's average daily net
assets. Amounts paid under the Plan are paid to the Distributor to compensate it
for the services provided and the expenses borne by it and others in the
distribution of the Fund's shares, including the payment of commissions for
sales of the Fund's shares and incentive compensation to, and expenses of, the
account executives of Dean Witter Reynolds Inc. ("DWR"), an affiliate of the
Investment Manager and Distributor, and other employees or selected
broker-dealers who engage in or support distribution of the Fund's shares or who
service shareholder accounts, including overhead and telephone expenses,
printing and distribution of prospectuses and reports used in connection with
the offering of the Fund's shares to other than current shareholders and
preparation, printing and distribution of sales literature and advertising
materials. In addition, the Distributor may be compensated under the Plan for
its opportunity costs in advancing such amounts, which compensation would be in
the form of a carrying charge on any unreimbursed expenses incurred by the
Distributor.
 
Provided that the Plan continues in effect, any cumulative expenses incurred but
not yet recovered may be recovered through future distribution fees from the
Fund and contingent deferred sales charges from the Fund's shareholders.
 
Although there is no legal obligation for the Fund to pay expenses incurred in
excess of payments made to the Distributor under the Plan and the proceeds of
contingent deferred sales charges paid by the investors upon redemption of
shares, if for any reason the Plan is terminated, the Trustees will consider at
that time the manner in which to treat such expenses. The Distributor has
advised the Fund that such excess amounts, including carrying charges, totaled
$74,316,532 at March 31, 1997.
 
                                       74
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
The Distributor has informed the Fund that for the six months ended March 31,
1997, it received approximately $83,000 in contingent deferred sales charges
from certain redemptions of the Fund's shares.
 
4. SECURITY TRANSACTIONS AND TRANSACTIONS WITH AFFILIATES
 
The cost of purchases and proceeds from sales of portfolio securities, excluding
short-term investments, for the six months ended March 31, 1997 aggregated
$219,355,749 and $179,336,258, respectively.
 
For the same period, the Fund incurred brokerage commissions of $1,218 with DWR
for portfolio transactions executed on behalf of the Fund.
 
Dean Witter Trust Company, an affiliate of the Investment Manager and
Distributor, is the Fund's transfer agent. At March 31, 1997, the Fund had
transfer agent fees and expenses payable of approximately $63,500.
 
The Fund has an unfunded noncontributory defined benefit pension plan covering
all independent Trustees of the Fund who will have served as independent
Trustees for at least five years at the time of retirement. Benefits under this
plan are based on years of service and compensation during the last five years
of service. Aggregate pension costs for the six months ended March 31, 1997
included in Trustees' fees and expenses in the Statement of Operations amounted
to $639. At March 31, 1997, the Fund had an accrued pension liability of $48,209
which is included in accrued expenses in the Statement of Assets and
Liabilities.
 
5. SHARES OF BENEFICIAL INTEREST
 
Transactions in shares of beneficial interest were as follows:
 
<TABLE>
<S>                                                                <C>           <C>              <C>           <C>
                                                                           FOR THE SIX
                                                                           MONTHS ENDED
                                                                          MARCH 31, 1997                 FOR THE YEAR
                                                                   ----------------------------
                                                                                                            ENDED
                                                                           (UNAUDITED)                SEPTEMBER 30, 1996
                                                                                                  --------------------------
 
                                                                     SHARES          AMOUNT         SHARES         AMOUNT
                                                                   -----------   --------------   -----------   ------------
Sold.............................................................    4,474,343   $   58,240,915     6,348,274   $ 78,466,531
Reinvestment of dividends........................................      345,885        4,492,066       715,417      8,632,934
Shares issued in connection with the acquisition of TCW/DW Global
 Convertible Trust (Note 6)......................................      --              --           1,665,682     19,179,898
                                                                   -----------   --------------   -----------   ------------
                                                                     4,820,228       62,732,981     8,729,373    106,279,363
Repurchased......................................................   (3,522,838)     (45,744,821)   (6,193,018)   (75,814,878)
                                                                   -----------   --------------   -----------   ------------
Net increase.....................................................    1,297,390   $   16,988,160     2,536,355   $ 30,464,485
                                                                   -----------   --------------   -----------   ------------
                                                                   -----------   --------------   -----------   ------------
</TABLE>
 
                                       75
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
NOTES TO FINANCIAL STATEMENTS MARCH 31, 1997 (UNAUDITED) CONTINUED
 
6. ACQUISITION OF TCW/DW GLOBAL CONVERTIBLE TRUST
 
As of the close of business on December 22, 1995, the Fund acquired all the net
assets of TCW/DW Global Convertible Trust ("Global Convertible") pursuant to a
plan of reorganization approved by the shareholders of Global Convertible on
December 19, 1995. The acquisition was accomplished by a tax-free exchange of
1,665,682 shares of the Fund at a net asset value of $11.52 for 1,811,960 shares
of Global Convertible.
 
7. FEDERAL INCOME TAX STATUS
 
At September 30, 1996, the Fund had an approximate net capital loss carryover to
offset future capital gains to the extent provided by regulations, which is
available through September 30 of the following years:
 
<TABLE>
  <S>          <C>        <C>          <C>          <C>
                      AMOUNTS IN THOUSANDS
  ------------------------------------------------------------
 
     1997         1998       1999         2000        TOTAL
  ----------   ---------- ----------   ----------   ----------
    $207,480   $   36,349 $   46,135   $   62,731   $  352,695
  ----------   ---------- ----------   ----------   ----------
  ----------   ---------- ----------   ----------   ----------
</TABLE>
 
Capital losses incurred after October 31 ("post-October" losses) within the
taxable year are deemed to arise on the first business day of the Fund's next
taxable year. The Fund incurred and will elect to defer net capital losses of
approximately $2,373,000 during fiscal 1996.
 
As of September 30, 1996, the Fund had temporary book/tax differences primarily
attributable to post-October losses and capital loss deferrals on wash sales.
 
                                       76
<PAGE>
DEAN WITTER CONVERTIBLE SECURITIES TRUST
FINANCIAL HIGHLIGHTS
 
Selected ratios and per share data for a share of beneficial interest
outstanding throughout each period:
<TABLE>
<CAPTION>
                                                      FOR THE SIX
                                                      MONTHS ENDED
                                                       MARCH 31,                  FOR THE YEAR ENDED SEPTEMBER 30
                                                          1997         ------------------------------------------------------
                                                      (UNAUDITED)            1996               1995               1994
- -----------------------------------------------------------------------------------------------------------------------------
 
<S>                                                 <C>                <C>                <C>                <C>
PER SHARE OPERATING PERFORMANCE:
 
Net asset value, beginning of period..............      $ 12.72            $      11.67       $      10.75       $      10.62
                                                         ------                  ------             ------             ------
 
Net investment income.............................         0.26                    0.55               0.60               0.42
 
Net realized and unrealized gain..................         0.27                    1.12               0.82               0.11
                                                         ------                  ------             ------             ------
 
Total from investment operations..................         0.53                    1.67               1.42               0.53
                                                         ------                  ------             ------             ------
 
Less dividends from net investment income.........        (0.29)                  (0.62)             (0.50)             (0.40)
                                                         ------                  ------             ------             ------
 
Net asset value, end of period....................      $ 12.96            $      12.72       $      11.67       $      10.75
                                                         ------                  ------             ------             ------
                                                         ------                  ------             ------             ------
 
TOTAL INVESTMENT RETURN+..........................         4.17%(1)               14.70%             13.68%             %5.02
 
RATIOS TO AVERAGE NET ASSETS:
 
Expenses..........................................         1.84%(2)               %1.89              %1.96              %1.93
 
Net investment income.............................         4.27%(2)               %4.78              %5.24              %3.68
 
SUPPLEMENTAL DATA:
 
Net assets, end of period, in millions............         $256                    $234               $185               $190
 
Portfolio turnover rate...........................           82%(1)               % 171              % 138              % 184
 
Average commission rate paid......................      $0.0566                 $0.0581          --                 --
 
<CAPTION>
 
                                                          1993               1992
- --------------------------------------------------------------------------------------------------------
<S>                                                 <C>                <C>
PER SHARE OPERATING PERFORMANCE:
Net asset value, beginning of period..............      $       8.92       $       8.67
                                                              ------             ------
Net investment income.............................              0.37               0.34
Net realized and unrealized gain..................              1.67               0.15
                                                              ------             ------
Total from investment operations..................              2.04               0.49
                                                              ------             ------
Less dividends from net investment income.........             (0.34)             (0.24)
                                                              ------             ------
Net asset value, end of period....................      $      10.62       $       8.92
                                                              ------             ------
                                                              ------             ------
TOTAL INVESTMENT RETURN+..........................             23.22%             %5.69
RATIOS TO AVERAGE NET ASSETS:
Expenses..........................................             %1.93              %1.92
Net investment income.............................             %3.44              %3.43
SUPPLEMENTAL DATA:
Net assets, end of period, in millions............              $208               $218
Portfolio turnover rate...........................             % 221              % 145
Average commission rate paid......................         --                 --
<FN>
 
- ---------------------
 +   Does not reflect the deduction of sales charge. Calculated based on the net
     asset value as of the last business day of the period.
(1)  Not annualized.
(2)  Annualized.
</TABLE>
 
                       SEE NOTES TO FINANCIAL STATEMENTS
 
                                       77
<PAGE>

                      DEAN WITTER CONVERTIBLE SECURITIES TRUST 

                              PART C  OTHER INFORMATION

Item 24. Financial Statements and Exhibits

    (a)  FINANCIAL STATEMENTS 

    (1)  Financial statements and schedules, included
         in Prospectus (Part A):
                                                             Page in
                                                           Prospectus
                                                           ----------

         Financial Highlights for the years 
         ended September 30, 1987, 1988, 1989, 1990, 
         1991, 1992, 1993, 1994, 1995 and 1996 and 
         for the six months ended March 31, 1997
         (unaudited). . . . . . . . . . . . . . . . . . . .      6
                          
    (2)  Financial statements included in the Statement of 
         Additional Information (Part B):                    Page in
                                                               SAI
                                                             -------

         Portfolio of Investments at September 30, 1996 . .     44

         Statement of Assets and Liabilities at            
         September 30, 1996 . . . . . . . . . . . . . . . .     53

         Statement of Operations for the year ended 
         September 30, 1996 . . . . . . . . . . . . . . . .     54

         Statement of Changes in Net Assets for the years  
         ended September 30, 1995 and September 30, 1996. .     55

         Notes to Financial Statements at September 30,    
         1996 . . . . . . . . . . . . . . . . . . . . . . .     56

         Financial Highlights for the years 
         ended September 30, 1987, 1988, 1989, 1990, 
         1991, 1992, 1993, 1994, 1995 and 1996. . . . . . .     61

         Portfolio of Investments at March 31, 1997
         (unaudited). . . . . . . . . . . . . . . . . . . .     62

         Statement of Assets and Liabilities at
         March 31, 1997 (unaudited) . . . . . . . . . . . .     69

         Statement of Operations for the six months ended 
         March 31, 1997 (unaudited) . . . . . . . . . . . .     70

<PAGE>

         Statement of Changes in Net Assets for the 
         year ended September 30, 1996 and for the six
         months ended March 31, 1997 (unaudited). . . . . .     71

         Notes to Financial Statements at March 31, 1997   
         (unaudited). . . . . . . . . . . . . . . . . . . .     72

         Financial Highlights for the years 
         ended September 30, 1992, 1993, 1994,
         1995 and 1996 and for the six months ended March
         31, 1997 (unaudited) . . . . . . . . . . . . . . .     77

         (3) Financial statements included in Part C:

              None

    (b)  EXHIBITS:

          1.    --  Form of Instrument Establishing and 
                    Designating Additional Classes.

          5.    --  Form of Investment Management Agreement 
                    between the Registrant an Dean Witter  
                    InterCapital Inc.

          6.(a) --  Form of Distribution Agreement between      
                    Registrant and Dean Witter Distributors     
                    Inc.

          6.(b) --  Form of Multiple-Class Distribution    
                    Agreement between the Registrant and Dean   
                    Witter Distributors Inc.
    
         11.    --  Consent of Independent Accountants.

         15.    --  Form of Amended and Restated Plan of 
                    Distribution Pursuant to Rule 12b-1. 

         27.    --  Financial Data Schedule.

         Other  --  Form of Multiple-Class Plan Pursuant to Rule 
                    18f-3.

Item 25. PERSONS CONTROLLED BY OR UNDER COMMON CONTROL WITH REGISTRANT.


         None


                                          2

<PAGE>

Item 26. NUMBER OF HOLDERS OF SECURITIES.

    (1)                             (2)
                                  Number of Record Holders
    Title of Class                    at June 30, 1997
    --------------                ------------------------
Shares of Beneficial Interest              93,102

Item 27. INDEMNIFICATION.

    Pursuant to Section 5.3 of the Registrant's Declaration of 
Trust and under Section 4.8 of the Registrant's By-Laws, the indemnification of
the Registrant's trustees, officers, employees and agents is permitted if it is
determined that they acted under the belief that their actions were in or not
opposed to the best interest of the Registrant, and, with respect to any
criminal proceeding, they had reasonable cause to believe their conduct was not
unlawful.  In addition, indemnification is permitted only if it is determined
that the actions in question did not render them liable by reason of willful
misfeasance, bad faith or gross negligence in the performance of their duties or
by reason of reckless disregard of their obligations and duties to the
Registrant.  Trustees, officers, employees and agents will be indemnified for
the expense of litigation if it is determined that they are entitled to
indemnification against any liability established in such litigation.  The
Registrant may also advance money for these expenses provided that they give
their undertakings to repay the Registrant unless their conduct is later
determined to permit indemnification.
 
    Pursuant to Section 5.2 of the Registrant's Declaration of Trust and
paragraph 8 of the Registrant's Investment Management Agreement, neither the
Investment Manager nor any trustee, officer, employee or agent of the Registrant
shall be liable for any action or failure to act, except in the case of bad
faith, willful misfeasance, gross negligence or reckless disregard of duties to
the Registrant.

    Insofar as indemnification for liabilities arising under the Securities Act
of 1933 (the "Act") may be permitted to trustees, officers and controlling
persons of the Registrant pursuant to the foregoing provisions or otherwise, the
Registrant has been advised that in the opinion of the  Securities and Exchange
Commission such indemnification is against public policy as expressed in the Act
and is, therefore, unenforceable.  In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a trustee, officer, or controlling person of the Registrant
in connection with the successful defense of any action, suit or proceeding) is
asserted against the Registrant by such trustee, officer or controlling person
in connection with 


                                          3

<PAGE>

the shares being registered, the Registrant will, unless in the opinion of its
counsel the matter has been settled by controlling precedent, submit to a court
of appropriate jurisdiction the question whether such indemnification by it is
against public policy as expressed in the Act, and will be governed by the final
adjudication of such issue.

    The Registrant hereby undertakes that it will apply the indemnification
provision of its by-laws in a manner consistent with Release 11330 of the
Securities and Exchange Commission under the Investment Company Act of 1940, so
long as the interpretation of Sections 17(h) and 17(i) of such Act remains in
effect.

    Registrant, in conjunction with the Investment Manager, Registrant's
Trustees, and other registered investment management companies managed by the
Investment Manager, maintains insurance on behalf of any person who is or was a
Trustee, officer, employee, or agent of Registrant, or who is or was serving at
the request of Registrant as a trustee, director, officer, employee or agent of
another trust or corporation, against any liability asserted against him and
incurred by him or arising out of his position.  However, in no event will
Registrant maintain insurance to indemnify any such person for any act for which
Registrant itself is not permitted to indemnify him.

Item 28.  BUSINESS AND OTHER CONNECTIONS OF INVESTMENT ADVISER. 

    See "The Fund and Its Management" in the Prospectus regarding the business
of the investment adviser.  The following information is given regarding
officers of Dean Witter InterCapital Inc.  InterCapital is a wholly-owned
subsidiary of Morgan Stanley, Dean Witter, Discover & Co.  The principal address
of the Dean Witter Funds is Two World Trade Center, New York, New York 10048.

    The term "Dean Witter Funds" used below refers to the following registered
investment companies:

CLOSED-END INVESTMENT COMPANIES
- -------------------------------
 (1) InterCapital Income Securities Inc.
 (2) High Income Advantage Trust
 (3) High Income Advantage Trust II
 (4) High Income Advantage Trust III
 (5) Municipal Income Trust
 (6) Municipal Income Trust II
 (7) Municipal Income Trust III
 (8) Dean Witter Government Income Trust
 (9) Municipal Premium Income Trust
(10) Municipal Income Opportunities Trust
(11) Municipal Income Opportunities Trust II
(12) Municipal Income Opportunities Trust III


                                          4

<PAGE>

(13) Prime Income Trust
(14) InterCapital Insured Municipal Bond Trust
(15) InterCapital Quality Municipal Income Trust
(16) InterCapital Quality Municipal Investment Trust
(17) InterCapital Insured Municipal Income Trust
(18) InterCapital California Insured Municipal Income Trust
(19) InterCapital Insured Municipal Trust
(20) InterCapital Quality Municipal Securities
(21) InterCapital New York Quality Municipal Securities
(22) InterCapital California Quality Municipal Securities
(23) InterCapital Insured California Municipal Securities 
(24) InterCapital Insured Municipal Securities

OPEN-END INVESTMENT COMPANIES:
- ------------------------------
 (1) Dean Witter Short-Term Bond Fund
 (2) Dean Witter Tax-Exempt Securities Trust
 (3) Dean Witter Tax-Free Daily Income Trust
 (4) Dean Witter Dividend Growth Securities Inc.
 (5) Dean Witter Convertible Securities Trust
 (6) Dean Witter Liquid Asset Fund Inc.
 (7) Dean Witter Developing Growth Securities Trust
 (8) Dean Witter Retirement Series
 (9) Dean Witter Federal Securities Trust
(10) Dean Witter World Wide Investment Trust
(11) Dean Witter U.S. Government Securities Trust
(12) Dean Witter Select Municipal Reinvestment Fund
(13) Dean Witter High Yield Securities Inc.
(14) Dean Witter Intermediate Income Securities
(15) Dean Witter New York Tax-Free Income Fund
(16) Dean Witter California Tax-Free Income Fund
(17) Dean Witter Health Sciences Trust
(18) Dean Witter California Tax-Free Daily Income Trust
(19) Dean Witter Global Asset Allocation Fund
(20) Dean Witter American Value Fund
(21) Dean Witter Strategist Fund
(22) Dean Witter Utilities Fund
(23) Dean Witter World Wide Income Trust
(24) Dean Witter New York Municipal Money Market Trust
(25) Dean Witter Capital Growth Securities
(26) Dean Witter Precious Metals and Minerals Trust
(27) Dean Witter European Growth Fund Inc.
(28) Dean Witter Global Short-Term Income Fund Inc.
(29) Dean Witter Pacific Growth Fund Inc.
(30) Dean Witter Multi-State Municipal Series Trust
(31) Dean Witter Short-Term U.S. Treasury Trust
(32) Dean Witter Diversified Income Trust
(33) Dean Witter U.S. Government Money Market Trust
(34) Dean Witter Global Dividend Growth Securities
(35) Active Assets California Tax-Free Trust
(36) Dean Witter Natural Resource Development Securities Inc.
(37) Active Assets Government Securities Trust
(38) Active Assets Money Trust
(39) Active Assets Tax-Free Trust
(40) Dean Witter Limited Term Municipal Trust


                                          5

<PAGE>

(41) Dean Witter Variable Investment Series
(42) Dean Witter Value-Added Market Series
(43) Dean Witter Global Utilities Fund
(44) Dean Witter High Income Securities
(45) Dean Witter National Municipal Trust
(46) Dean Witter International SmallCap Fund
(47) Dean Witter Mid-Cap Growth Fund
(48) Dean Witter Select Dimensions Investment Series
(49) Dean Witter Balanced Growth Fund
(50) Dean Witter Balanced Income Fund
(51) Dean Witter Hawaii Municipal Trust
(52) Dean Witter Capital Appreciation Fund
(53) Dean Witter Intermediate Term U.S. Treasury Trust 
(54) Dean Witter Information Fund
(55) Dean Witter Japan Fund
(56) Dean Witter Income Builder Fund
(57) Dean Witter Special Value Fund
(58) Dean Witter Financial Services Trust
(59) Dean Witter Market Leader Trust

The term "TCW/DW Funds" refers to the following registered investment 
companies:

OPEN-END INVESTMENT COMPANIES
- -----------------------------
 (1) TCW/DW Core Equity Trust
 (2) TCW/DW North American Government Income Trust
 (3) TCW/DW Latin American Growth Fund
 (4) TCW/DW Income and Growth Fund 
 (5) TCW/DW Small Cap Growth Fund
 (6) TCW/DW Balanced Fund 
 (7) TCW/DW Total Return Trust
 (8) TCW/DW Mid-Cap Equity Trust
 (9) TCW/DW Global Telecom Trust
 (10)TCW/DW Strategic Income Trust

CLOSED-END INVESTMENT COMPANIES
- -------------------------------
 (1) TCW/DW Term Trust 2000
 (2) TCW/DW Term Trust 2002 
 (3) TCW/DW Term Trust 2003
 (4) TCW/DW Emerging Markets Opportunities Trust


                                          6

<PAGE>

NAME AND POSITION            OTHER SUBSTANTIAL BUSINESS, PROFESSION, VOCATION 
WITH DEAN WITTER             OR EMPLOYMENT, INCLUDING NAME, PRINCIPAL ADDRESS 
INTERCAPITAL INC.            AND NATURE OF CONNECTION                        
- -----------------            ------------------------------------------------
Charles A. Fiumefreddo       Executive Vice President and Director of Dean 
Chairman, Chief              Witter Reynolds Inc. ("DWR"); Chairman, Chief
Executive Officer and        Executive Officer and Director of Dean Witter
Director                     Distributors Inc. ("Distributors") and Dean
                             Witter Services Company Inc. ("DWSC"); Chairman 
                             and Director of Dean Witter Trust Company    
                             ("DWTC"); Chairman, Director or Trustee, President 
                             and Chief Executive Officer of the Dean Witter 
                             Funds and Chairman, Chief Executive Officer and 
                             Trustee of the TCW/DW Funds; Director and/or
                             officer of various Morgan Stanley, Dean Witter,
                             Discover & Co. ("MSDWD") subsidiaries; Formerly
                             Executive Vice President and Director of Dean 
                             Witter, Discover & Co.

Philip J. Purcell            Chairman, Chief Executive Officer and Director of
Director                     of MSDWD and DWR; Director of DWSC and
                             Distributors; Director or Trustee of the Dean
                             Witter Funds; Director and/or officer of various
                             MSDWD subsidiaries.

Richard M. DeMartini         President and Chief Operating Officer
Director                     of Dean Witter Capital,  a division of DWR;
                             Director of DWR, DWSC, Distributors and DWTC;
                             Trustee of the TCW/DW Funds.

James F. Higgins             President and Chief Operating Officer of
Director                     Dean Witter Financial; Director of DWR,
                             DWSC, Distributors and DWTC.

Thomas C. Schneider          Executive Vice President and Chief Strategic  
Executive Vice               and Administrative Officer of MSDWD; Executive
President, Chief             Vice President and Chief Financial Officer of 
Financial Officer and        DWSC and Distributors; Director of DWR,
Director                     DWSC and Distributors.
    
    
Christine A. Edwards         Executive Vice President, Chief Legal Officer
Director                     and Secretary of MSDWD; Executive Vice
                             President, Secretary and Chief Legal Officer
                             of Distributors; Director of DWR, DWSC and
                             Distributors.

Robert M. Scanlan            President and Chief Operating Officer of DWSC, 
President and Chief          Executive Vice President of Distributors; 
Operating Officer            Executive Vice President and Director of DWTC;
                             Vice President of the Dean Witter Funds and the 
                             TCW/DW Funds.


                                          7

<PAGE>

NAME AND POSITION            OTHER SUBSTANTIAL BUSINESS, PROFESSION, VOCATION 
WITH DEAN WITTER             OR EMPLOYMENT, INCLUDING NAME, PRINCIPAL ADDRESS 
INTERCAPITAL INC.            AND NATURE OF CONNECTION                        
- -----------------            ------------------------------------------------

Mitchell M. Merin            President and Chief Strategic Officer of DWSC,
President and Chief          Executive Vice President of Distributors; 
Strategic Officer            Executive Vice President and Director of DWTC;
                             Executive Vice President and Director of DWR;
                             Director of SPS Transaction Services, Inc. and
                             various other MSDWD subsidiaries.

John B. Van Heuvelen         President, Chief Operating Officer and Director
Executive Vice               of DWTC.
President

Joseph J. McAlinden
Executive Vice President
and Chief Investment         Vice President of the Dean Witter Funds and
Officer                      Director of DWTC.

Barry Fink                   Assistant Secretary of DWR; Senior Vice President,
Senior Vice President,       Secretary and General Counsel of DWSC; Senior Vice
Secretary and General        President, Assistant Secretary and Assistant 
Counsel                      General Counsel of Distributors; Vice President,
                             Secretary and General Counsel of the Dean Witter 
                             Funds and the TCW/DW Funds.

Peter M. Avelar    
Senior Vice President        Vice President of various Dean Witter Funds.

Mark Bavoso   
Senior Vice President        Vice President of various Dean Witter Funds.

Richard Felegy
Senior Vice President   

Edward F. Gaylor   
Senior Vice President        Vice President of various Dean Witter Funds.

Robert S. Giambrone          Senior Vice President of DWSC, Distributors     
Senior Vice President        and DWTC and Director of DWTC; Vice President
                             of the Dean Witter Funds and the TCW/DW Funds. 

Rajesh K. Gupta    
Senior Vice President        Vice President of various Dean Witter Funds.

Kenton J. Hinchcliffe   
Senior Vice President        Vice President of various Dean Witter Funds.

Kevin Hurley
Senior Vice President        Vice President of various Dean Witter Funds.

Jenny Beth Jones             Vice President of Dean Witter Special Value Fund.
Senior Vice President


                                          8

<PAGE>

NAME AND POSITION            OTHER SUBSTANTIAL BUSINESS, PROFESSION, VOCATION 
WITH DEAN WITTER             OR EMPLOYMENT, INCLUDING NAME, PRINCIPAL ADDRESS 
INTERCAPITAL INC.            AND NATURE OF CONNECTION                        
- -----------------            ------------------------------------------------

John B. Kemp, III            Director of the Provident Savings Bank, Jersey
Senior Vice President        City, New Jersey.

Anita H. Kolleeny  
Senior Vice President        Vice President of various Dean Witter Funds.

Jonathan R. Page
Senior Vice President        Vice President of various Dean Witter Funds.

Ira N. Ross   
Senior Vice President        Vice President of various Dean Witter Funds.

Guy G. Rutherfurd, Jr.       Vice President of Dean Witter Market Leader
Senior Vice President        Trust.

Rafael Scolari               Vice President of Prime Income Trust.
Senior Vice President

Rochelle G. Siegel 
Senior Vice President        Vice President of various Dean Witter Funds.

Jayne M. Stevlingston        Vice President of various Dean Witter Funds.
Senior Vice President

Paul D. Vance
Senior Vice President        Vice President of various Dean Witter Funds.

Elizabeth A. Vetell     
Senior Vice President

James F. Willison
Senior Vice President        Vice President of various Dean Witter Funds.

Ronald J. Worobel  
Senior Vice President        Vice President of various Dean Witter Funds.

Douglas Brown 
First Vice President

Thomas F. Caloia             First Vice President and Assistant Treasurer of
First Vice President         DWSC, Assistant Treasurer of Distributors;
and Assistant                Treasurer and Chief Financial Officer of the
Treasurer                    Dean Witter Funds and the TCW/DW Funds.

Thomas Chronert    
First Vice President

Rosalie Clough
First Vice President


                                          9

<PAGE>

NAME AND POSITION            OTHER SUBSTANTIAL BUSINESS, PROFESSION, VOCATION 
WITH DEAN WITTER             OR EMPLOYMENT, INCLUDING NAME, PRINCIPAL ADDRESS 
INTERCAPITAL INC.            AND NATURE OF CONNECTION                        
- -----------------            ------------------------------------------------


Marilyn K. Cranney           Assistant Secretary of DWR; First Vice President
First Vice President         and Assistant Secretary of DWSC; Assistant
and Assistant Secretary      Secretary of the Dean Witter Funds and the TCW/DW
                             Funds.

Michael Interrante           First Vice President and Controller of DWSC; 
First Vice President         Assistant Treasurer of Distributors;First Vice
and Controller               President and Treasurer of DWTC. 

David Johnson
First Vice President

Stanley Kapica
First Vice President

Robert Zimmerman
First Vice President

Dale Albright
Vice President

Joan G. Allman
Vice President

Andrew Arbenz
Vice President

Joseph Arcieri
Vice President               Vice President of various Dean Witter Funds.

Kirk Balzer
Vice President               Vice President of Various Dean Witter Funds.

Nancy Belza
Vice President

Dale Boettcher
Vice President

Joseph Cardwell
Vice President

Philip Casparius
Vice President

B. Catherine Connelly
Vice President

Salvatore DeSteno
Vice President               Vice President of DWSC.


                                          10


<PAGE>

NAME AND POSITION            OTHER SUBSTANTIAL BUSINESS, PROFESSION, VOCATION 
WITH DEAN WITTER             OR EMPLOYMENT, INCLUDING NAME, PRINCIPAL ADDRESS 
INTERCAPITAL INC.            AND NATURE OF CONNECTION                        
- -----------------            ------------------------------------------------

Frank J. DeVito    
Vice President               Vice President of DWSC.

Bruce Dunn
Vice President

Jeffrey D. Geffen
Vice President

Deborah Genovese
Vice President

Michael Geringer
Vice President

Stephen Greenhut
Vice President

Peter W. Gurman
Vice President

Matthew Haynes               Vice President of Dean Witter
Vice President               Variable Investment Series

Peter Hermann  
Vice President               Vice President of various Dean Witter Funds

Elizabeth Hinchman
Vice President

David Hoffman
Vice President

Christopher Jones
Vice President

James P. Kastberg
Vice President

Michelle Kaufman   
Vice President               Vice President of various Dean Witter Funds

Michael Knox   
Vice President               Vice President of various Dean Witter Funds 

Paula LaCosta
Vice President               Vice President of various Dean Witter Funds.

Thomas Lawlor
Vice President


                                          11

<PAGE>

NAME AND POSITION            OTHER SUBSTANTIAL BUSINESS, PROFESSION, VOCATION 
WITH DEAN WITTER             OR EMPLOYMENT, INCLUDING NAME, PRINCIPAL ADDRESS 
INTERCAPITAL INC.            AND NATURE OF CONNECTION                        
- -----------------            ------------------------------------------------

Gerard J. Lian     
Vice President               Vice President of various Dean Witter Funds.

Catherine Maniscalco         Vice President of Dean Witter Natural 
Vice President               Resource Development Securities Inc.

Albert McGarity
Vice President

LouAnne D. McInnis           Vice President and Assistant Secretary of DWSC;
Vice President and           Assistant Secretary of the Dean Witter Funds and 
Assistant Secretary          the TCW/DW Funds.

Sharon K. Milligan 
Vice President

Julie Morrone 
Vice President

Mary Beth Mueller
Vice President

David Myers                  Vice President of Dean Witter Natural   
Vice President               Resource Development Securities Inc.

James Nash
Vice President

Richard Norris
Vice President

Carsten Otto                 Vice President and Assistant Secretary of DWSC;
Vice President and           Assistant Secretary of the Dean Witter Funds and 
Assistant Secretary          the TCW/DW Funds.

George Paoletti
Vice President

Anne Pickrell                Vice President of Dean Witter Global Short-
Vice President               Term Income Fund Inc.
    
Michael Roan
Vice President

Hugh Rose
Vice President

Robert Rossetti              Vice President of Dean Witter Precious Metal and 
Vice President               Minerals Trust.


                                          12

<PAGE>

NAME AND POSITION            OTHER SUBSTANTIAL BUSINESS, PROFESSION, VOCATION 
WITH DEAN WITTER             OR EMPLOYMENT, INCLUDING NAME, PRINCIPAL ADDRESS 
INTERCAPITAL INC.            AND NATURE OF CONNECTION                        
- -----------------            ------------------------------------------------

Ruth Rossi                   Vice President and Assistant Secretary of DWSC;
Vice President and           Assistant Secretary of the Dean Witter Funds and 
Assistant Secretary          the TCW/DW Funds.

Carl F. Sadler
Vice President

Peter Seeley                 Vice President of Dean Witter World
Vice President               Wide Income Trust

Naomi Stein
Vice President

Kathleen H. Stromberg   
Vice President               Vice President of various Dean Witter Funds.

Marybeth Swisher
Vice President

Vinh Q. Tran
Vice President               Vice President of various Dean Witter Funds.

Robert Vanden Assem
Vice President

Alice Weiss
Vice President               Vice President of various Dean Witter Funds.

Katherine Wickham
Vice President

Item 29.   PRINCIPAL UNDERWRITERS

    (a)  Dean Witter Distributors Inc. ("Distributors"), a Delaware
         corporation, is the principal underwriter of the Registrant.
         Distributors is also the principal underwriter of the following
         investment companies:

 (1)        Dean Witter Liquid Asset Fund Inc.
 (2)        Dean Witter Tax-Free Daily Income Trust
 (3)        Dean Witter California Tax-Free Daily Income Trust
 (4)        Dean Witter Retirement Series
 (5)        Dean Witter Dividend Growth Securities Inc.
 (6)        Dean Witter Global Asset Allocation
 (7)        Dean Witter World Wide Investment Trust
 (8)        Dean Witter Capital Growth Securities 
 (9)        Dean Witter Convertible Securities Trust
(10)        Active Assets Tax-Free Trust
(11)        Active Assets Money Trust
(12)        Active Assets California Tax-Free Trust


                                          13

<PAGE>

(13)        Active Assets Government Securities Trust
(14)        Dean Witter Short-Term Bond Fund
(15)        Dean Witter Mid-Cap Growth Fund
(16)        Dean Witter U.S. Government Securities Trust
(17)        Dean Witter High Yield Securities Inc.
(18)        Dean Witter New York Tax-Free Income Fund
(19)        Dean Witter Tax-Exempt Securities Trust
(20)        Dean Witter California Tax-Free Income Fund
(21)        Dean Witter Limited Term Municipal Trust
(22)        Dean Witter Natural Resource Development Securities Inc.
(23)        Dean Witter World Wide Income Trust
(24)        Dean Witter Utilities Fund
(25)        Dean Witter Strategist Fund
(26)        Dean Witter New York Municipal Money Market Trust
(27)        Dean Witter Intermediate Income Securities
(28)        Prime Income Trust
(29)        Dean Witter European Growth Fund Inc.
(30)        Dean Witter Developing Growth Securities Trust
(31)        Dean Witter Precious Metals and Minerals Trust
(32)        Dean Witter Pacific Growth Fund Inc.
(33)        Dean Witter Multi-State Municipal Series Trust
(34)        Dean Witter Federal Securities Trust
(35)        Dean Witter Short-Term U.S. Treasury Trust
(36)        Dean Witter Diversified Income Trust
(37)        Dean Witter Health Sciences Trust
(38)        Dean Witter Global Dividend Growth Securities
(39)        Dean Witter American Value Fund
(40)        Dean Witter U.S. Government Money Market Trust
(41)        Dean Witter Global Short-Term Income Fund Inc.
(42)        Dean Witter Value-Added Market Series
(43)        Dean Witter Global Utilities Fund
(44)        Dean Witter High Income Securities
(45)        Dean Witter National Municipal Trust    
(46)        Dean Witter International SmallCap Fund
(47)        Dean Witter Balanced Growth Fund
(48)        Dean Witter Balanced Income Fund
(49)        Dean Witter Hawaii Municipal Trust
(50)        Dean Witter Variable Investment Series   
(51)        Dean Witter Capital Appreciation Fund
(52)        Dean Witter Intermediate Term U.S. Treasury Trust
(53)        Dean Witter Information Fund
(54)        Dean Witter Japan Fund
(55)        Dean Witter Income Builder Fund
(56)        Dean Witter Special Value Fund
(57)        Dean Witter Financial Services Trust
(58)        Dean Witter Market Leader Trust
 (1)        TCW/DW Core Equity Trust
 (2)        TCW/DW North American Government Income Trust
 (3)        TCW/DW Latin American Growth Fund
 (4)        TCW/DW Income and Growth Fund
 (5)        TCW/DW Small Cap Growth Fund
 (6)        TCW/DW Balanced Fund
 (7)        TCW/DW Total Return Trust
 (8)        TCW/DW Mid-Cap Equity Trust


                                          14

<PAGE>

 (9)        TCW/DW Global Telecom Trust 
 (10)       TCW/DW Strategic Income Trust

    (b)  The following information is given regarding directors and officers of
    Distributors not listed in Item 28 above.  The principal address of
    Distributors is Two World Trade Center, New York, New York 10048.  None of
    the following persons has any position or office with the Registrant.


                                        Positions and
                                        Office with
    Name                                Distributors 
    ----                                -------------

    Fredrick K. Kubler                 Senior Vice President, Assistant
                                       Secretary and Chief Compliance
                                       Officer.

    Michael T. Gregg                   Vice President and Assistant
                                       Secretary.


Item 30.   LOCATION OF ACCOUNTS AND RECORDS

    All accounts, books and other documents required to be maintained by
Section 31(a) of the Investment Company Act of 1940 and the Rules thereunder are
maintained by the Investment Manager at its offices, except records relating to
holders of shares issued by the Registrant, which are maintained by the
Registrant's Transfer Agent, at its place of business as shown in the
prospectus.


Item 31.   MANAGEMENT SERVICES

    Registrant is not a party to any such management-related service contract.

Item 32.   UNDERTAKINGS

    Registrant hereby undertakes to furnish each person to whom a prospectus is
delivered with a copy of the Registrant's latest annual report to shareholders,
upon request and without charge.


                                          15
<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
Post-Effective Amendment to the Registration Statement to be signed on its
behalf by the undersigned, thereunto duly authorized, in the City of New York
and State of New York on the 17th day of July, 1997.

                                   DEAN WITTER CONVERTIBLE SECURITIES TRUST    
                                                  
                                           By      /s/ Barry Fink 
                                               -------------------------------
                                                       Barry Fink    
                                              Vice President and Secretary

    Pursuant to the requirements of the Securities Act of 1933, this
Post-Effective Amendment No. 13 has been signed below by the following persons
in the capacities and on the dates indicated.

     Signatures                    Title                      Date
     ----------                    -----                      ----

(1) Principal Executive Officer    President, Chief 
                                   Executive Officer,
                                   Trustee and Chairman
By  /s/ Charles A. Fiumefreddo                               7/17/97
        --------------------------
        Charles A. Fiumefreddo

(2) Principal Financial Officer    Treasurer and Principal
                                   Accounting Officer
                   
By   /s/ Thomas F. Caloia                                    7/17/97
         -------------------------
         Thomas F. Caloia

(3) Majority of the Trustees  

    Charles A. Fiumefreddo (Chairman)
    Philip J. Purcell

By   /s/ Barry Fink                                          7/17/97 
         -------------------------
         Barry Fink    
         Attorney-in-Fact

    Michael Bozic 
    Edwin J. Garn              
    John R. Haire              
    Manuel H. Johnson         
    Michael E. Nugent
    John L. Schroeder

By   /s/ David M. Butowsky                                   7/17/97
         -------------------------
         David M. Butowsky  
         Attorney-in-Fact 
<PAGE>

                                       Exhibits  
                                      ----------

 1.   --  Form of Instrument Establishing and                             
          Designating Additional Classes.
         
 5.   --  Form of Investment Management Agreement                         
          between the Registrant an Dean Witter InterCapital Inc.

6.(a) --  Form of Distribution Agreement between                         
          Registrant and Dean Witter Distributors Inc.     

6.(b) --  Form of Multiple-Class Distribution                            
          Agreement between Registrant and Dean Witter
          Distributors Inc.
    
11.    -- Consent of Independent Accountants.

15.   --  Form of Amended and Restated Plan of                            
          Distribution Pursuant to Rule 12b-1. 

27.    -- Financial Data Schedule.

Other  -- Form of Multiple-Class Plan Pursuant to Rule 
          18f-3.

<PAGE>


                                     CERTIFICATE


         The undersigned hereby certifies that he is the Secretary of Dean
Witter Convertible Securities Trust (the "Trust"), an unincorporated business
trust organized under the laws of the Commonwealth of Massachusetts, that
annexed hereto is an Instrument Establishing and Designating Additional Classes
of Shares of the Trust unanimously adopted by the Trustees of the Trust on June
30, 1997, as provided in Section 6.9(g) of the said Declaration, said Instrument
to take effect on July 28, 1997, and I do hereby further certify that such
Instrument has not been amended and is on the date hereof in full force and
effect.

         Dated this 28th day of July, 1997.


                                                        ------------------------
                                                        Barry Fink              
                                                        Secretary               




(SEAL)   

<PAGE>



                       DEAN WITTER CONVERTIBLE SECURITIES TRUST

                       INSTRUMENT ESTABLISHING AND DESIGNATING
                             ADDITIONAL CLASSES OF SHARES

WHEREAS, Dean Witter Convertible Securities Trust (the "Trust") was established
by the Declaration of Trust dated May 21, 1985, as amended from time to time
(the "Declaration"), under the laws of the Commonwealth of Massachusetts;

WHEREAS, Section 6.9(g) of the Declaration provides that the establishment and
designation of any additional class of shares shall be effective upon the
execution by a majority of the then Trustees of an instrument setting forth such
establishment and designation and the relative rights, preferences, voting
powers, restrictions, limitations as to dividends, qualifications, and terms and
conditions of such class, or as otherwise provided in such instrument, which
instrument shall have the status of an amendment to the Declaration; and

WHEREAS, the Trustees of the Trust have deemed it advisable to establish and
designate three additional classes of shares and to designate classes for the
existing shares held prior to July 28, 1997 ("Existing Class") as provided
herein.

NOW, THEREFORE, BE IT RESOLVED, pursuant to Section 6.9(g) of the Declaration,
there are hereby established and designated three additional classes of shares,
to be known as:  Class A, Class C and Class D (the "Additional Classes"), each
of which shall be subject to the relative rights, preferences, voting powers,
restrictions, limitations as to dividends, qualifications, and terms and
conditions of redemption set forth in the Declaration with respect to the
Existing Class, except to the extent the DEAN WITTER FUNDS MULTIPLE CLASS PLAN 
PURSUANT TO RULE 18f-3 attached hereto as EXHIBIT A sets forth differences (i)
between each of the Additional Classes, or (ii) among each of the Existing Class
and the Additional Classes; and be it further

RESOLVED, pursuant to Section 6.9(g) of the Declaration, all shares of the Trust
held prior to July 28, 1997 are hereby designated as Class B shares of the
Trust. 

This instrument may be executed in more than one counterpart, each of which
shall be deemed an original, but all of which together shall constitute one and
the same document.

<PAGE>

IN WITNESS THEREOF, the undersigned, the Trustees of the Trust, have executed 

this instrument this 30th day of June, 1997.



/s/ Michael Bozic                      /s/ Manuel H. Johnson
Michael Bozic, as Trustee              Manuel H. Johnson, as Trustee
and not individually                   and not individually
c/o Levitz Furniture Corp.             c/o Johnson Smick International Inc.
6111 Broken Sound Parkway, N.W.        1133 Connecticut Avenue, N.W.  
Boca Raton, FL  33487                  Washington, D.C.  20036
                                         



/s/ Charles A. Fiumefreddo             /s/ Michael E. Nugent
Charles A. Fiumefreddo, as Trustee     Michael E. Nugent, as Trustee
and not individually                   and not individually
Two World Trade Center                 c/o Triumph Capital, L.P.
New York, NY  10048                    237 Park Avenue
                                       New York, NY  10017



/s/ Edwin J. Garn                      /s/ Philip J. Purcell
Edwin J. Garn, as Trustee              Philip J. Purcell, as Trustee
and not individually                   and not individually
c/o Huntsman Chemical Corporation      Two World Trade Center
500 Huntsman Way                       New York, NY  10048
Salt Lake City, UT  84111




/s/ John R. Haire                      /s/ John L. Schroeder  
John R. Haire, as Trustee              John L. Schroeder, as Trustee
and not individually                   and not individually
Two World Trade Center                 c/o Gordon Altman Butowsky Weitzen
New York, NY  10048                      Shalov & Wein 
                                       Counsel to the Independent Trustees
                                       114 West 47th Street
                                       New York, NY  10036

<PAGE>

STATE OF NEW YORK  )
                   )ss:
COUNTY OF NEW YORK )


    On this 30th day of June, 1997, MICHAEL BOZIC, CHARLES A. FIUMEFREDDO,
EDWIN J. GARN, JOHN R. HAIRE, MANUEL H. JOHNSON, MICHAEL E. NUGENT, PHILIP J.
PURCELL and JOHN L. SCHROEDER, known to me to be the individuals described in
and who executed the foregoing instrument, personally appeared before me and
they severally acknowledged the foregoing instrument to be their free act and
deed.



                                  
                                  /s/ Marilyn K. Cranney                        
                                  --------------------------------
                                  Notary Public


My Commission expires:

MARILYN K. CRANNEY
NOTARY PUBLIC, STATE OF NEW YORK
NO. 24-4795538
QUALIFIED IN KINGS COUNTY
COMMISSION EXPIRES MAY 31,1999                   


<PAGE>
                                                                       EXHIBIT A
 
                               DEAN WITTER FUNDS
                              MULTIPLE CLASS PLAN
                             PURSUANT TO RULE 18f-3
 
INTRODUCTION
 
    This plan (the "Plan") is adopted pursuant to Rule 18f-3(d) of the
Investment Company Act of 1940, as amended (the "1940 Act"), and will be
effective as of July 28, 1997. The Plan relates to shares of the open-end
investment companies to which Dean Witter InterCapital Inc. acts as investment
manager, that are listed on Schedule A, as may be amended from time to time
(each, a "Fund" and collectively, the "Funds"). The Funds are distributed
pursuant to a system (the "Multiple Class System") in which each class of shares
(each, a "Class" and collectively, the "Classes") of a Fund represents a pro
rata interest in the same portfolio of investments of the Fund and differs only
to the extent outlined below.
 
I.  DISTRIBUTION ARRANGEMENTS
 
    One or more Classes of shares of the Funds are offered for purchase by
investors with the sales load structures described below. In addition, pursuant
to Rule 12b-1 under the 1940 Act, the Funds have each adopted a Plan of
Distribution (the "12b-1 Plan") under which shares of certain Classes are
subject to the service and/or distribution fees ("12b-1 fees") described below.
 
    1.  CLASS A SHARES
 
    Class A shares are offered with a front-end sales load ("FESL"). The
schedule of sales charges applicable to a Fund and the circumstances under which
the sales charges are subject to reduction are set forth in each Fund's current
prospectus. As stated in each Fund's current prospectus, Class A shares may be
purchased at net asset value (without a FESL): (i) in the case of certain large
purchases of such shares; and (ii) by certain limited categories of investors,
in each case, under the circumstances and conditions set forth in each Fund's
current prospectus. Class A shares purchased at net asset value may be subject
to a contingent deferred sales charge ("CDSC") on redemptions made within one
year of purchase. Further information relating to the CDSC, including the manner
in which it is calculated, is set forth in paragraph 6 below. Class A shares are
also subject to payments under each Fund's 12b-1 Plan to reimburse Dean Witter
Distributors Inc., Dean Witter Reynolds Inc. ("DWR"), its affiliates and other
broker-dealers for distribution expenses incurred by them specifically on behalf
of the Class, assessed at an annual rate of up to 0.25% of average daily net
assets. The entire amount of the 12b-1 fee represents a service fee within the
meaning of National Association of Securities Dealers, Inc. ("NASD") guidelines.
 
    2.  CLASS B SHARES
 
    Class B shares are offered without a FESL, but will in most cases be subject
to a six-year declining CDSC which is calculated in the manner set forth in
paragraph 6 below. Class B shares purchased by certain qualified
employer-sponsored benefit plans are subject to a three-year declining CDSC
which is calculated in the manner set forth in paragraph 6 below. The schedule
of CDSC charges applicable to each Fund is set forth in each Fund's current
prospectus. With the exception of certain of the Funds which have a different
formula described below (Dean Witter American Value Fund, Dean Witter Natural
Resource Development Securities Inc., Dean Witter Strategist Fund and Dean
Witter Dividend Growth Securities Inc.)(1), Class B
 
- ------------
 
(1)The payments under the 12b-1 Plan for each of Dean Witter American Value
Fund, Dean Witter Natural Resource Development Securities Inc. and Dean Witter
Dividend Growth Securities Inc. are assessed at the annual rate of 1.0% of the
lesser of: (a) the average daily aggregate gross sales of the Fund's Class B
shares since the inception of the Fund's Plan (not including reinvestment of
dividends or capital gains distributions), less the average daily aggregate net
asset value of the Fund's Class B shares redeemed since the Plan's inception
upon which a contingent deferred sales charge has been imposed or waived, or (b)
the average daily net assets of Class B attributable to shares issued, net of
related shares redeemed, since inception of the Plan. The payments under the
12b-1 Plan for the Dean Witter Strategist Fund are assessed at the annual rate
of: (i) 1% of the lesser of (a) the average daily aggregate gross sales of the
Fund's Class B shares since the effectiveness of the first amendment of the Plan
on November 8, 1989 (not including reinvestment of dividends or capital gains
distributions), less the average daily aggregate net asset value of the Fund's
Class B shares redeemed since the effectiveness of the first amended Plan, upon
which a contingent deferred sales charge has been imposed or waived, or (b) the
average daily net assets of Class B attributable to shares issued, net of
related shares redeemed, since the effectiveness of the first amended Plan; plus
(ii) 0.25% of the average daily net assets of Class B attributable to shares
issued, net of related shares redeemed, prior to effectiveness of the first
amended Plan.
 
                                       1
<PAGE>
shares are also subject to a fee under each Fund's respective 12b-1 Plan,
assessed at the annual rate of up to 1.0% of either: (a) the lesser of (i) the
average daily aggregate gross sales of the Fund's Class B shares since the
inception of the Fund (not including reinvestment of dividends or capital gains
distributions), less the average daily aggregate net asset value of the Fund's
Class B shares redeemed since the Fund's inception upon which a CDSC has been
imposed or waived, or (ii) the average daily net assets of Class B; or (b) the
average daily net assets of Class B. A portion of the 12b-1 fee equal to up to
0.25% of the Fund's average daily net assets is characterized as a service fee
within the meaning of the NASD guidelines and the remaining portion of the 12b-1
fee, if any, is characterized as an asset-based sales charge. Also, Class B
shares have a conversion feature ("Conversion Feature") under which such shares
convert to Class A shares after a certain holding period. Details of the
Conversion Feature are set forth in Section IV below.
 
    3.  CLASS C SHARES
 
    Class C shares are offered without imposition of a FESL, but will in most
cases be subject to a CDSC of 1.0% on redemptions made within one year after
purchase. Further information relating to the CDSC is set forth in paragraph 6
below. In addition, Class C shares, under each Fund's 12b-1 Plan, are subject to
12b-1 payments to reimburse Dean Witter Distributors Inc., DWR, its affiliates
and other broker-dealers for distribution expenses incurred by them specifically
on behalf of the Class, assessed at the annual rate of up to 1.0% of the average
daily net assets of the Class. A portion of the 12b-1 fee equal to up to 0.25%
of the Fund's average daily net assets is characterized as a service fee within
the meaning of NASD guidelines. Unlike Class B shares, Class C shares do not
have the Conversion Feature.
 
    4.  CLASS D SHARES
 
    Class D shares are offered without imposition of a FESL, CDSC or a 12b-1 fee
for purchases of Fund shares by (i) investors meeting an initial minimum
investment requirement and (ii) certain other limited categories of investors,
in each case, as may be approved by the Boards of Directors/Trustees of the
Funds and as disclosed in each Fund's current prospectus.
 
    5.  ADDITIONAL CLASSES OF SHARES
 
    The Boards of Directors/Trustees of the Funds have the authority to create
additional Classes, or change existing Classes, from time to time, in accordance
with Rule 18f-3 under the 1940 Act.
 
    6.  CALCULATION OF THE CDSC
 
    Any applicable CDSC is calculated based upon the lesser of net asset value
of the shares at the time of purchase or at the time of redemption. The CDSC
does not apply to amounts representing an increase in share value due to capital
appreciation and shares acquired through the reinvestment of dividends or
capital gains distributions. The CDSC schedule applicable to a Fund and the
circumstances in which the CDSC is subject to waiver are set forth in each
Fund's prospectus.
 
II.  EXPENSE ALLOCATIONS
 
    Expenses incurred by a Fund are allocated among the various Classes of
shares pro rata based on the net assets of the Fund attributable to each Class,
except that 12b-1 fees relating to a particular Class are allocated directly to
that Class. In addition, other expenses associated with a particular Class
(except advisory or custodial fees), may be allocated directly to that Class,
provided that such expenses are reasonably identified as specifically
attributable to that Class and the direct allocation to that Class is approved
by the Fund's Board of Directors/Trustees.
 
III.  CLASS DESIGNATION
 
    All shares of the Funds held prior to July 28, 1997 (other than the shares
held by certain employee benefit plans established by DWR and its affiliate, SPS
Transaction Services, Inc., shares of Funds offered with a FESL, and shares of
Dean Witter Balanced Growth Fund and Dean Witter Balanced Income Fund) have been
designated Class B shares. Shares held prior to July 28, 1997 by such employee
benefit plans have been designated Class D shares. Shares held prior to July 28,
1997 of Funds offered with a FESL have been designated Class D shares. In
addition, shares of Dean Witter American Value Fund purchased prior to April 30,
1984, shares of Dean Witter Strategist Fund purchased prior to November 8, 1989
and shares of Dean Witter Natural Resource Development Securities Inc. and Dean
Witter Dividend Growth Securities Inc. purchased prior to July 2, 1984 (with
respect to such shares of each Fund, including such proportion of shares
acquired through reinvestment of dividends and capital gains distributions as
the total number of shares acquired prior to each of the preceding dates in this
sentence bears to the total number of shares purchased and owned by the
shareholder of that Fund) have been designated Class D shares. Shares of Dean
Witter Balanced Growth Fund and Dean Witter Balanced Income Fund held prior to
July 28, 1997 have
 
                                       2
<PAGE>
been designated Class C shares except that shares of Dean Witter Balanced Growth
Fund and Dean Witter Balanced Income Fund held prior to July 28, 1997 that were
acquired in exchange for shares of an investment company offered with a CDSC
have been designated Class B shares and those that were acquired in exchange for
shares of an investment company offered with a FESL have been designated Class A
shares.
 
IV.  THE CONVERSION FEATURE
 
    Class B shares held before May 1, 1997 will convert to Class A shares in
May, 2007, except that Class B shares which are purchased before July 28, 1997
by trusts for which Dean Witter Trust Company ("DWTC") or Dean Witter Trust FSB
("DWTFSB") provides discretionary trustee services will convert to Class A
shares on or about August 29, 1997 (the CDSC will not be applicable to such
shares upon the conversion). In all other instances, Class B shares of each Fund
will automatically convert to Class A shares, based on the relative net asset
values of the shares of the two Classes on the conversion date, which will be
approximately ten (10) years after the date of the original purchase.
Conversions will be effected once a month. The 10 year period will be calculated
from the last day of the month in which the shares were purchased or, in the
case of Class B shares acquired through an exchange or a series of exchanges,
from the last day of the month in which the original Class B shares were
purchased, provided that shares originally purchased before May 1, 1997 will
convert to Class A shares in May, 2007. Except as set forth below, the
conversion of shares purchased on or after May 1, 1997 will take place in the
month following the tenth anniversary of the purchase. There will also be
converted at that time such proportion of Class B shares acquired through
automatic reinvestment of dividends owned by the shareholder as the total number
of his or her Class B shares converting at the time bears to the total number of
outstanding Class B shares purchased and owned by the shareholder. In the case
of Class B shares held by a 401(k) plan or other employer-sponsored plan
qualified under Section 401(a) of the Internal Revenue Code (the "Code") and for
which DWTC or DWTFSB serves as Trustee or the 401(k) Support Services Group of
DWR serves as recordkeeper, all Class B shares will convert to Class A shares on
the conversion date of the first shares of a Fund purchased by that plan. In the
case of Class B shares previously exchanged for shares of an "Exchange Fund" (as
such term is defined in the prospectus of each Fund), the period of time the
shares were held in the Exchange Fund (calculated from the last day of the month
in which the Exchange Fund shares were acquired) is excluded from the holding
period for conversion. If those shares are subsequently re-exchanged for Class B
shares of a Fund, the holding period resumes on the last day of the month in
which Class B shares are reacquired.
 
    Effectiveness of the Conversion Feature is subject to the continuing
availability of a ruling of the Internal Revenue Service or an opinion of
counsel to the effect that (i) the conversion of shares does not constitute a
taxable event under the Code; (ii) Class A shares received on conversion will
have a basis equal to the shareholder's basis in the converted Class B shares
immediately prior to the conversion; and (iii) Class A shares received on
conversion will have a holding period that includes the holding period of the
converted Class B shares. The Conversion Feature may be suspended if the Ruling
or opinion is no longer available. In such event, Class B shares would continue
to be subject to Class B fees under the applicable Fund's 12b-1 Plan.
 
V.  EXCHANGE PRIVILEGES
 
    Shares of each Class may be exchanged for shares of the same Class of the
other Funds and for shares of certain other investment companies without the
imposition of an exchange fee as described in the prospectuses and statements of
additional information of the Funds. The exchange privilege of each Fund may be
terminated or revised at any time by the Fund upon such notice as may be
required by applicable regulatory agencies as described in each Fund's
prospectus.
 
VI.  VOTING
 
    Each Class shall have exclusive voting rights on any matter that relates
solely to its 12b-1 Plan, except that Class B shareholders will have the right
to vote on any proposed material increase in Class A's expenses, including
payments under the Class A 12b-1 Plan, if such proposal is submitted separately
to Class A shareholders. If the amount of expenses, including payments under the
Class A 12b-1 Plan, is increased materially without the approval of Class B
shareholders, the Fund will establish a new Class A for Class B shareholders
whose shares automatically convert on the same terms as applied to Class A
before the increase. In addition, each Class shall have separate voting rights
on any matter submitted to shareholders in which the interests of one Class
differ from the interests of any other Class.
 
                                       3
<PAGE>
                               DEAN WITTER FUNDS
                   MULTIPLE CLASS PLAN PURSUANT TO RULE 18f-3
                                   SCHEDULE A
                                AT JULY 28, 1997
 
1)         Dean Witter American Value Fund
2)         Dean Witter Balanced Growth Fund
3)         Dean Witter Balanced Income Fund
4)         Dean Witter California Tax-Free Income Fund
5)         Dean Witter Capital Appreciation Fund
6)         Dean Witter Capital Growth Securities
7)         Dean Witter Convertible Securities Trust
8)         Dean Witter Developing Growth Securities Trust
9)         Dean Witter Diversified Income Trust
10)        Dean Witter Dividend Growth Securities Inc.
11)        Dean Witter European Growth Fund Inc.
12)        Dean Witter Federal Securities Trust
13)        Dean Witter Financial Services Trust
14)        Dean Witter Global Asset Allocation Fund
15)        Dean Witter Global Dividend Growth Securities
16)        Dean Witter Global Utilities Fund
17)        Dean Witter Health Sciences Trust
18)        Dean Witter High Yield Securities Inc.
19)        Dean Witter Income Builder Fund
20)        Dean Witter Information Fund
21)        Dean Witter Intermediate Income Securities
22)        Dean Witter International SmallCap Fund
23)        Dean Witter Japan Fund
24)        Dean Witter Managers' Select Fund
25)        Dean Witter Market Leader Trust
26)        Dean Witter Mid-Cap Growth Fund
27)        Dean Witter Natural Resource Development Securities Inc.
28)        Dean Witter New York Tax-Free Income Fund
29)        Dean Witter Pacific Growth Fund Inc.
30)        Dean Witter Precious Metals and Minerals Trust
31)        Dean Witter Special Value Fund
32)        Dean Witter Strategist Fund
33)        Dean Witter Tax-Exempt Securities Trust
34)        Dean Witter U.S. Government Securities Trust
35)        Dean Witter Utilities Fund
36)        Dean Witter Value-Added Market Series/Equity Portfolio
37)        Dean Witter World Wide Income Trust
38)        Dean Witter World Wide Investment Trust
 
                                       4

<PAGE>

                        INVESTMENT MANAGEMENT AGREEMENT
 
    AGREEMENT made as of the 31st day of May, 1997 by and between Dean Witter
Convertible Securities Trust, an unincorporated business trust organized under
the laws of the Commonwealth of Massachusetts (hereinafter called the "Fund"),
and Dean Witter InterCapital Inc., a Delaware corporation (hereinafter called
the "Investment Manager"):
 
    WHEREAS, The Fund is engaged in business as an open-end management
investment company and is registered as such under the Investment Company Act of
1940, as amended (the "Act"); and
 
    WHEREAS, The Investment Manager is registered as an investment adviser under
the Investment Advisers Act of 1940, and engages in the business of acting as
investment adviser; and
 
    WHEREAS, The Fund desires to retain the Investment Manager to render
management and investment advisory services in the manner and on the terms and
conditions hereinafter set forth; and
 
    WHEREAS, The Investment Manager desires to be retained to perform services
on said terms and conditions:
 
    Now, Therefore, this Agreement
 
                              W I T N E S S E T H:
 
that in consideration of the premises and the mutual covenants hereinafter
contained, the Fund and the Investment Manager agree as follows:
 
          
    1. The Fund hereby retains the Investment Manager to act as investment
manager of the Fund and, subject to the supervision of the Trustees, to
supervise the investment activities of the Fund as hereinafter set forth.
Without limiting the generality of the foregoing, the Investment Manager shall
obtain and evaluate such information and advice relating to the economy,
securities and commodities markets and securities and commodities as it deems
necessary or useful to discharge its duties hereunder; shall continuously manage
the assets of the Fund in a manner consistent with the investment objectives and
policies of the Fund; shall determine the securities and commodities to be
purchased, sold or otherwise disposed of by the Fund and the timing of such
purchases, sales and dispositions; and shall take such further action, including
the placing of purchase and sale orders on behalf of the Fund, as the Investment
Manager shall deem necessary or appropriate. The Investment Manager shall also
furnish to or place at the disposal of the Fund such of the information,
evaluations, analyses and opinions formulated or obtained by the Investment
Manager in the discharge of its duties as the Fund may, from time to time,
reasonably request.
 
    2. The Investment Manager shall, at its own expense, maintain such staff and
employ or retain such personnel and consult with such other persons as it
shall from time to time determine to be necessary or useful to the performance
of its obligations under this Agreement. Without limiting the generality of the
foregoing, the staff and personnel of the Investment Manager shall be deemed to
include persons employed or otherwise retained by the Investment Manager to
furnish statistical and other factual data, advice regarding economic factors
and trends, information with respect to technical and scientific developments,
and such other information, advice and assistance as the Investment Manager may
desire. The Investment Manager shall, as agent for the Fund, maintain the Fund's
records and books of account (other than those maintained by the Fund's transfer
agent, registrar, custodian and other agencies). All such books and records so
maintained shall be the property of the Fund and, upon request therefor, the
Investment Manager shall surrender to the Fund such of the books and records so
requested.
 
    3. The Fund will, from time to time, furnish or otherwise make available to
the Investment Manager such financial reports, proxy statements and other
information relating to the business and affairs of the Fund as the Investment
Manager may reasonably require in order to discharge its duties and obligations
hereunder.
 
    4. The Investment Manager shall bear the cost of rendering the investment
management and supervisory services to be performed by it under this
Agreement, and shall, at its own expense, pay the compensation of the officers
and employees, if any, of the Fund, and provide such office space, facilities
and equipment and such clerical help and bookkeeping services as the Fund shall
reasonably require in the conduct of its
<PAGE>
business. The Investment Manager shall also bear the cost of telephone service,
heat, light, power and other utilities provided to the Fund.
 
    5. The Fund assumes and shall pay or cause to be paid all other expenses of
the Fund, including without limitation: fees pursuant to any plan of
distribution that the Fund may adopt; the charges and expenses of any registrar,
any custodian or depository appointed by the Fund for the safekeeping of its
cash, portfolio securities or commodities and other property, and any stock
transfer or dividend agent or agents appointed by the Fund; brokers' commissions
chargeable to the Fund in connection with portfolio transactions to which the
Fund is a party; all taxes, including securities or commodities issuance and
transfer taxes, and fees payable by the Fund to federal, state or other
governmental agencies; the cost and expense of engraving or printing
certificates representing shares of the Fund; all costs and expenses in
connection with the registration and maintenance of registration of the Fund and
its shares with the Securities and Exchange Commission and various states and
other jurisdictions (including filing fees and legal fees and disbursements of
counsel); the cost and expense of printing, including typesetting, and
distributing prospectuses and statements of additional information of the Fund
and supplements thereto to the Fund's shareholders; all expenses of
shareholders' and Trustees' meetings and of preparing, printing and mailing
proxy statements and reports to shareholders; fees and travel expenses of
Trustees or members of any advisory board or committee who are not employees of
the Investment Manager or any corporate affiliate of the Investment Manager; all
expenses incident to the payment of any dividend, distribution, withdrawal or
redemption, whether in shares or in cash; charges and expenses of any outside
service used for pricing of the Fund's shares; charges and expenses of legal
counsel, including counsel to the Trustees of the Fund who are not interested
persons (as defined in the Act) of the Fund or the Investment Manager, and of
independent accountants, in connection with any matter relating to the Fund;
membership dues of industry associations; interest payable on Fund borrowings;
postage; insurance premiums on property or personnel (including officers and
Trustees) of the Fund which inure to its benefit; extraordinary expenses
(including but not limited to legal claims and liabilities and litigation costs
and any indemnification related thereto); and all other charges and costs of the
Fund's operation unless otherwise explicitly provided herein.
 
    6. For the services to be rendered, the facilities furnished, and the
expenses assumed by the Investment Manager, the Fund shall pay to the
Investment Manager monthly compensation determined by applying the following
annual rates to the Fund's daily net assets: 0.60% of daily net assets up to
$750 million; 0.55% of the next $250 million; 0.50% of the next $500 million;
0.475% of the next $500 million; 0.45% of the next $1 billion; and 0.425% of
daily net assets over $3 billion. Except as hereinafter set forth, compensation
under this Agreement shall be calculated and accrued daily and the amounts of
the daily accruals shall be paid monthly. Such calculations shall be made by
applying 1/365ths of the annual rates to the Fund's net assets each day
determined as of the close of business on that day or the last previous business
day. If this Agreement becomes effective subsequent to the first day of a month
or shall terminate before the last day of a month, compensation for that part of
the month this Agreement is in effect shall be prorated in a manner consistent
with the calculation of the fees as set forth above.
 
    Subject to the provisions of paragraph 7 hereof, payment of the Investment
Manager's compensation for the preceding month shall be made as promptly as
possible after completion of the computations contemplated by paragraph 7
hereof.
 
    7. In the event the operating expenses of the Fund, including amounts
payable to the Investment Manager pursuant to paragraph 6 hereof, for any
fiscal year ending on a date on which this Agreement is in effect, exceed the
expense limitations applicable to the Fund imposed by state securities laws or
regulations thereunder, as such limitations may be raised or lowered from time
to time, the Investment Manager shall reduce its management fee to the extent of
such excess and, if required, pursuant to any such laws or regulations, will
reimburse the Fund for annual operating expenses in excess of any expense
limitation that may be applicable; provided, however, there shall be excluded
from such expenses the amount of any interest, taxes, brokerage commissions,
distribution fees and extraordinary expenses (including but not limited to legal
claims and liabilities and litigation costs and any indemnification related
thereto) paid or payable by the Fund. Such reduction, if any, shall be computed
and accrued daily, shall be settled on a monthly basis, and shall be based upon
the expense limitation applicable to the Fund as at the end of the last
 
                                       2
<PAGE>
business day of the month. Should two or more such expense limitations be
applicable as at the end of the last business day of the month, that expense
limitation which results in the largest reduction in the Investment Manager's
fee shall be applicable.
 
    For purposes of this provision, should any applicable expense limitation be
based upon the gross income of the Fund, such gross income shall include, but
not be limited to, interest on debt securities in the Fund's portfolio accrued
to and including the last day of the Fund's fiscal year, and dividends declared
on equity securities in the Fund's portfolio, the record dates for which fall on
or prior to the last day of such fiscal year, but shall not include gains from
the sale of securities.
 
    8. The Investment Manager will use its best efforts in the supervision and
management of the investment activities of the Fund, but in the absence
of willful misfeasance, bad faith, gross negligence or reckless disregard of its
obligations hereunder, the Investment Manager shall not be liable to the Fund or
any of its investors for any error of judgment or mistake of law or for any act
or omission by the Investment Manager or for any losses sustained by the Fund or
its investors.
 
    9. Nothing contained in this Agreement shall prevent the Investment Manager
or any affiliated person of the Investment Manager from acting as
investment adviser or manager for any other person, firm or corporation and
shall not in any way bind or restrict the Investment Manager or any such
affiliated person from buying, selling or trading any securities or commodities
for their own accounts or for the account of others for whom they may be acting.
Nothing in this Agreement shall limit or restrict the right of any Trustee,
officer or employee of the Investment Manager to engage in any other business or
to devote his or her time and attention in part to the management or other
aspects of any other business whether of a similar or dissimilar nature.
 
    10. This Agreement shall remain in effect until April 30, 1999 and from year
to year thereafter provided such continuance is approved at least
annually by the vote of holders of a majority, as defined in the Investment
Company Act of 1940, as amended (the "Act"), of the outstanding voting
securities of the Fund or by the Trustees of the Fund; provided that in either
event such continuance is also approved annually by the vote of a majority of
the Trustees of the Fund who are not parties to this Agreement or "interested
persons" (as defined in the Act) of any such party, which vote must be cast in
person at a meeting called for the purpose of voting on such approval; provided,
however, that (a) the Fund may, at any time and without the payment of any
penalty, terminate this Agreement upon thirty days' written notice to the
Investment Manager, either by majority vote of the Trustees of the Fund or by
the vote of a majority of the outstanding voting securities of the Fund; (b)
this Agreement shall immediately terminate in the event of its assignment (to
the extent required by the Act and the rules thereunder) unless such automatic
terminations shall be prevented by an exemptive order of the Securities and
Exchange Commission; and (c) the Investment Manager may terminate this Agreement
without payment of penalty on thirty days' written notice to the Fund. Any
notice under this Agreement shall be given in writing, addressed and delivered,
or mailed post-paid, to the other party at the principal office of such party.
 
    11. This Agreement may be amended by the parties without the vote or consent
of the shareholders of the Fund to supply any omission, to cure, correct
or supplement any ambiguous, defective or inconsistent provision hereof, or if
they deem it necessary to conform this Agreement to the requirements of
applicable federal laws or regulations, but neither the Fund nor the Investment
Manager shall be liable for failing to do so.
 
    12. This Agreement shall be construed in accordance with the laws of the
State of New York and the applicable provisions of the Act. To the extent
the applicable law of the State of New York, or any of the provisions herein,
conflicts with the applicable provisions of the Act, the latter shall control.
 
    13. The Investment Manager and the Fund each agree that the name "Dean
Witter," which comprises a component of the Fund's name, is a property
right of Dean Witter Reynolds Inc. The Fund agrees and consents that (i) it will
only use the name "Dean Witter" as a component of its name and for no other
purpose, (ii) it will not purport to grant to any third party the right to use
the name "Dean Witter" for any purpose, (iii) the Investment Manager or its
parent, Morgan Stanley, Dean Witter, Discover & Co., or any corporate affiliate
of the Investment Manager's parent, may use or grant to others the right to use
the name
 
                                       3
<PAGE>
"Dean Witter," or any combination or abbreviation thereof, as all or a portion
of a corporate or business name or for any commercial purpose, including a grant
of such right to any other investment company, (iv) at the request of the
Investment Manager or its parent, the Fund will take such action as may be
required to provide its consent to the use of the name "Dean Witter," or any
combination or abbreviation thereof, by the Investment Manager or its parent or
any corporate affiliate of the Investment Manager's parent, or by any person to
whom the Investment Manager or its parent or any corporate affiliate of the
Investment Manager's parent shall have granted the right to such use, and (v)
upon the termination of any investment advisory agreement into which the
Investment Manager and the Fund may enter, or upon termination of affiliation of
the Investment Manager with its parent, the Fund shall, upon request by the
Investment Manager or its parent, cease to use the name "Dean Witter" as a
component of its name, and shall not use the name, or any combination or
abbreviation thereof, as a part of its name or for any other commercial purpose,
and shall cause its officers, Trustees and shareholders to take any and all
actions which the Investment Manager or its parent may request to effect the
foregoing and to reconvey to the Investment Manager or its parent any and all
rights to such name.
 
    14. The Declaration of Trust establishing Dean Witter Convertible Securities
Trust, dated May 21, 1985, a copy of which, together with all amendments
thereto (the "Declaration"), is on file in the office of the Secretary of the
Commonwealth of Massachusetts, provides that the name Dean Witter Convertible
Securities Trust refers to the Trustees under the Declaration collectively as
Trustees, but not as individuals or personally; and no Trustee, shareholder,
officer, employee or agent of Dean Witter Convertible Securities Trust shall be
held to any personal liability, nor shall resort be had to their private
property for the satisfaction of any obligation or claim or otherwise, in
connection with the affairs of said Dean Witter Convertible Securities Trust,
but the Trust Estate only shall be liable.
 
    IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Agreement on the day and year first above written in New York, New York.
 
                                       DEAN WITTER CONVERTIBLE SECURITIES TRUST
  
                                       By: /s/ Barry Fink
                                           ....................................
 
Attest:
   /s/ Ruth Rossi
 .................................
 
                                       DEAN WITTER INTERCAPITAL INC.
 
                                       By: /s/ Charles A. Fiumefreddo
                                           ....................................
 
Attest:
   /s/ Marilyn K. Cranney
 .................................
             
 
                                       4

<PAGE>
                               DEAN WITTER FUNDS

                             DISTRIBUTION AGREEMENT
 
    AGREEMENT made as of this 31st day of May, 1997 between each of the open-end
investment  companies to which Dean Witter  InterCapital Inc. acts as investment
manager, that are  listed on Schedule  A, as may  be amended from  time to  time
(each,  a "Fund"  and collectively, the  "Funds"), and  Dean Witter Distributors
Inc., a Delaware corporation (the "Distributor").
 
                              W I T N E S S E T H:
 
    WHEREAS, each Fund is registered as an open-end investment company under the
Investment Company Act of 1940,  as amended (the "1940 Act"),  and it is in  the
interest of each Fund to offer its shares for sale continuously, and
 
    WHEREAS,  each Fund and the Distributor wish to enter into an agreement with
each other with respect to the  continuous offering of each Fund's  transferable
shares, of $0.01 par value (the "Shares"), to commence on the date listed above,
in  order to promote the growth of  each Fund and facilitate the distribution of
its shares.
 
    NOW, THEREFORE, the parties agree as follows:
 
    SECTION 1.  APPOINTMENT OF THE DISTRIBUTOR.
 
    (a) Each Fund hereby appoints  the Distributor as the principal  underwriter
and  distributor of the Fund to sell Shares to the public on the terms set forth
in this Agreement and that Fund's prospectus and the Distributor hereby  accepts
such appointment and agrees to act hereunder. Each Fund, during the term of this
Agreement,  shall sell Shares  to the Distributor upon  the terms and conditions
set forth herein.
 
    (b) The Distributor  agrees to  purchase Shares,  as principal  for its  own
account,  from  each Fund  and to  sell  Shares as  principal to  investors, and
securities dealers, including Dean Witter Reynolds Inc. ("DWR"), an affiliate of
the Distributor, upon the terms described  herein and in that Fund's  prospectus
(the  "Prospectus")  and statement  of  additional information  included  in the
Fund's registration statement (the "Registration Statement") most recently filed
from time to time  with the Securities and  Exchange Commission (the "SEC")  and
effective under the Securities Act of 1933, as amended (the "1933 Act"), and the
1940 Act or as the Prospectus may be otherwise amended or supplemented and filed
with the SEC pursuant to Rule 497 under the 1933 Act.
 
    SECTION  2.   EXCLUSIVE  NATURE OF  DUTIES.   The  Distributor shall  be the
exclusive principal underwriter and  distributor of each  Fund, except that  the
exclusive  rights granted to the Distributor to  sell the Shares shall not apply
to  Shares  issued  by  each  Fund:  (i)  in  connection  with  the  merger   or
consolidation  of any other investment company  or personal holding company with
the Fund or the  acquisition by purchase or  otherwise of all (or  substantially
all)  the assets or the outstanding shares of any such company by the Fund; (ii)
pursuant to reinvestment of dividends  or capital gains distributions; or  (iii)
pursuant to the reinstatement privilege afforded redeeming shareholders.
 
    SECTION 3.  PURCHASE OF SHARES FROM EACH FUND.
 
    (a)  The Distributor shall have  the right to buy  from each Fund the Shares
needed, but  not more  than the  Shares needed  (except for  clerical errors  in
transmission),   to  fill  unconditional  orders  for  Shares  placed  with  the
Distributor by investors or securities dealers. The price which the  Distributor
shall  pay for  the Shares  so purchased from  the Fund  shall be  the net asset
value, determined as set forth in the Prospectus, used in determining the public
offering price on which such orders were based.
 
    (b) The Shares are to  be resold by the  Distributor at the public  offering
price  of Shares as set  forth in the Prospectus,  to investors or to securities
dealers, including DWR, who  have entered into  selected dealer agreements  with
the  Distributor upon  the terms  and conditions set  forth in  Section 7 hereof
("Selected Dealers").
 
                                       1
<PAGE>
    (c) Each Fund  shall have the  right to suspend  the sale of  the Shares  at
times  when  redemption is  suspended pursuant  to the  conditions set  forth in
Section (f) hereof. Each Fund shall also  have the right to suspend the sale  of
the  Shares if trading on the New York Stock Exchange shall have been suspended,
if a  banking  moratorium  shall have  been  declared  by federal  or  New  York
authorities,  or if there shall have  been some other extraordinary event which,
in the judgment of a Fund, makes it impracticable to sell its Shares.
 
    (d) Each Fund, or  any agent of  a Fund designated in  writing by the  Fund,
shall  be promptly  advised of  all purchase orders  for Shares  received by the
Distributor. Any order may be rejected by a Fund; provided, however, that a Fund
will not arbitrarily or without reasonable cause refuse to accept orders for the
purchase of Shares. The Distributor will confirm orders upon their receipt,  and
each  Fund (or its agent) upon receipt of payment therefor and instructions will
deliver share  certificates  for  such  Shares or  a  statement  confirming  the
issuance of Shares. Payment shall be made to the Fund in New York Clearing House
funds.  The Distributor agrees to cause such payment and such instructions to be
delivered promptly to the Fund (or its agent).
 
    (e) With respect to Shares sold  by any Selected Dealer, the Distributor  is
authorized to direct each Fund's transfer agent to receive instructions directly
from  the Selected  Dealer on  behalf of the  Distributor as  to registration of
Shares in the names of investors and  to confirm issuance of the Shares to  such
investors.  The Distributor is also authorized to instruct the transfer agent to
receive payment directly from the Selected Dealer on behalf of the  Distributor,
for  prompt transmittal to each  Fund's custodian, of the  purchase price of the
Shares. In such event the Distributor shall obtain from the Selected Dealer  and
maintain a record of such registration instructions and payments.
 
    SECTION 4.  REPURCHASE OR REDEMPTION OF SHARES.
 
    (a)  Any of the outstanding Shares of  a Fund may be tendered for redemption
at any time, and each Fund agrees to redeem its Shares so tendered in accordance
with the applicable provisions set forth in its Prospectus. The price to be paid
to redeem the Shares  shall be equal  to the net asset  value determined as  set
forth  in the Prospectus  less, in the case  of a Fund  whose Shares are offered
with a contingent deferred sales charge ("CDSC"), any applicable CDSC. Upon  any
redemption of Shares the Fund shall pay the total amount of the redemption price
in New York Clearing House funds in accordance with applicable provisions of the
Prospectus.
 
    (b)  In the case of  a Fund whose Shares are  offered with a front-end sales
charge, the redemption by a  Fund of any of its  Shares purchased by or  through
the Distributor will not affect the applicable front-end sales charge secured by
the  Distributor or  any Selected  Dealer in  the course  of the  original sale,
except that if any Shares are tendered for redemption within seven business days
after the date of the  confirmation of the original  purchase, the right to  the
applicable  front-end sales charge shall be forfeited by the Distributor and the
Selected Dealer which sold such Shares.
 
    (c) In the case of a Fund whose Shares are offered with a CDSC, the proceeds
of any redemption  of Shares  shall be  paid by each  Fund as  follows: (i)  any
applicable  CDSC shall be paid to the Distributor or to the Selected Dealer, or,
when applicable,  pursuant to  the  Rules of  the  Association of  the  National
Association  of Securities Dealers, Inc. ("NASD"), retained by the Fund and (ii)
the balance  shall  be paid  to  the redeeming  shareholders,  in each  case  in
accordance  with applicable  provisions of its  Prospectus in  New York Clearing
House funds. The Distributor is authorized to  direct a Fund to pay directly  to
the  Selected Dealer any CDSC payable by a Fund to the Distributor in respect of
Shares sold by the Selected Dealer to the redeeming shareholders.
 
    (d) The Distributor  is authorized,  as agent  for the  Fund, to  repurchase
Shares,  represented by a share certificate which  is delivered to any office of
the Distributor  in accordance  with  applicable provisions  set forth  in  each
Fund's Prospectus. The Distributor shall promptly transmit to the transfer agent
of  the Fund for  redemption all Shares  so delivered. The  Distributor shall be
responsible for the accuracy of instructions transmitted to the Fund's  transfer
agent in connection with all such repurchases.
 
    (e)  The Distributor  is authorized, as  agent for each  Fund, to repurchase
Shares held  in  a  shareholder's  account  with  a  Fund  for  which  no  share
certificate   has   been   issued,   upon   the   telephonic   request   of  the
 
                                       2
<PAGE>
shareholders, or at  the discretion  of the Distributor.  The Distributor  shall
promptly  transmit to the transfer  agent of the Fund,  for redemption, all such
orders for repurchase of Shares. Payment for Shares repurchased may be made by a
Fund to the  Distributor for  the account  of the  shareholder. The  Distributor
shall  be responsible for the accuracy of instructions transmitted to the Fund's
transfer agent in connection with all such repurchases.
 
    (f) Redemption of its Shares or payment by a Fund may be suspended at  times
when  the New York  Stock Exchange is  closed, when trading  on said Exchange is
restricted, when an emergency exists as a result of which disposal by a Fund  of
securities  owned by it  is not reasonably  practicable or it  is not reasonably
practicable for a  Fund fairly  to determine  the value  of its  net assets,  or
during any other period when the SEC, by order, so permits.
 
    (g)  With respect to its Shares tendered for redemption or repurchase by any
Selected Dealer on  behalf of its  customers, the Distributor  is authorized  to
instruct  the  transfer agent  of  a Fund  to  accept orders  for  redemption or
repurchase directly from the Selected Dealer on behalf of the Distributor and to
instruct the  Fund to  transmit payments  for such  redemptions and  repurchases
directly  to the Selected Dealer on behalf of the Distributor for the account of
the shareholder.  The Distributor  shall obtain  from the  Selected Dealer,  and
shall  maintain, a record of such  orders. The Distributor is further authorized
to obtain from the Fund, and shall  maintain, a record of payment made  directly
to the Selected Dealer on behalf of the Distributor.
 
    SECTION 5.  DUTIES OF THE FUND.
 
    (a)  Each Fund shall  furnish to the Distributor  copies of all information,
financial statements  and  other papers  which  the Distributor  may  reasonably
request for use in connection with the distribution of its Shares, including one
certified  copy, upon  request by the  Distributor, of  all financial statements
prepared by the Fund and examined  by independent accountants. Each Fund  shall,
at the expense of the Distributor, make available to the Distributor such number
of copies of its Prospectus as the Distributor shall reasonably request.
 
    (b)  Each Fund shall take,  from time to time,  but subject to the necessary
approval of its  shareholders, all  necessary action to  fix the  number of  its
authorized  Shares and to  register Shares under  the 1933 Act,  to the end that
there will  be  available  for sale  such  number  of Shares  as  investors  may
reasonably be expected to purchase.
 
    (c)  Each Fund  shall use  its best efforts  to pay  the filing  fees for an
appropriate number of its Shares  to be sold under  the securities laws of  such
states  as the Distributor and  the Fund may approve.  Any qualification to sell
its Shares in a state may be withheld, terminated or withdrawn by a Fund at  any
time  in its discretion.  As provided in  Section 8(c) hereof,  such filing fees
shall be paid  by the Fund.  The Distributor shall  furnish any information  and
other  material relating to its  affairs and activities as  may be required by a
Fund in connection with the sale of its Shares in any state.
 
    (d) Each  Fund  shall,  at  the expense  of  the  Distributor,  furnish,  in
reasonable  quantities upon request by the Distributor, copies of its annual and
interim reports.
 
    SECTION 6.  DUTIES OF THE DISTRIBUTOR.
 
    (a) The Distributor shall sell shares of each Fund through DWR and may  sell
shares  through other  securities dealers  and its  own Account  Executives, and
shall devote reasonable  time and  effort to promote  sales of  the Shares,  but
shall  not be obligated to  sell any specific number  of Shares. The services of
the Distributor  hereunder are  not  exclusive and  it  is understood  that  the
Distributor  may act  as principal  underwriter for  other registered investment
companies, so  long as  the  performance of  its  obligations hereunder  is  not
impaired  thereby. It is  also understood that  Selected Dealers, including DWR,
may also sell shares for other registered investment companies.
 
    (b)  Neither  the  Distributor  nor  any  Selected  Dealer  shall  give  any
information  or  make any  representations, other  than  those contained  in the
Registration  Statement  or   related  Prospectus  and   any  sales   literature
specifically approved by the appropriate Fund.
 
                                       3
<PAGE>
    (c)  The  Distributor agrees  that  it will  at  all times  comply  with the
applicable terms and limitations of the Rules of the Association of the NASD.
 
    SECTION 7.  SELECTED DEALERS AGREEMENTS.
 
    (a) The  Distributor shall  have the  right to  enter into  selected  dealer
agreements  with Selected Dealers  for the sale of  Shares. In making agreements
with Selected Dealers, the  Distributor shall act only  as principal and not  as
agent  for a Fund. Shares  sold to Selected Dealers shall  be for resale by such
dealers only at  the public  offering price set  forth in  the Prospectus.  With
respect to Funds whose Shares are offered with a front-end sales charge, in such
agreement  the  Distributor shall  have  the right  to  fix the  portion  of the
applicable front-end  sales  charge  which  may be  allocated  to  the  Selected
Dealers.
 
    (b)  Within the United  States, the Distributor shall  offer and sell Shares
only to Selected Dealers that are members in good standing of the NASD.
 
    (c) The Distributor shall adopt and  follow procedures, as approved by  each
Fund,  for the  confirmation of  sales of its  Shares to  investors and Selected
Dealers, the collection of amounts payable by investors and Selected Dealers  on
such  sales, and the cancellation of unsettled transactions, as may be necessary
to comply with the requirements of the NASD, as such requirements may from  time
to time exist.
 
    SECTION 8.  PAYMENT OF EXPENSES.
 
    (a)  Each Fund shall bear all costs and expenses of the Fund, including fees
and disbursements of legal counsel  including counsel to the  Directors/Trustees
of  each Fund who are not interested persons (as defined in the 1940 Act) of the
Fund or the  Distributor, and  independent accountants, in  connection with  the
preparation  and filing of any required Registration Statements and Prospectuses
and all  amendments  and supplements  thereto,  and the  expense  of  preparing,
printing,  mailing  and otherwise  distributing  prospectuses and  statements of
additional  information,  annual  or  interim  reports  or  proxy  materials  to
shareholders.
 
    (b)  The Distributor  shall bear all  expenses incurred by  it in connection
with its duties  and activities under  this Agreement including  the payment  to
Selected  Dealers of any sales commissions,  service fees and other expenses for
sales of a Fund's  Shares (except such expenses  as are specifically  undertaken
herein  by a  Fund) incurred  or paid  by Selected  Dealers, including  DWR. The
Distributor shall  bear  the  costs  and expenses  of  preparing,  printing  and
distributing  any  supplementary sales  literature  used by  the  Distributor or
furnished by it for use by Selected  Dealers in connection with the offering  of
the  Shares for  sale. Any expenses  of advertising incurred  in connection with
such offering will also be the  obligation of the Distributor. It is  understood
and agreed that, so long as a Fund's Plan of Distribution pursuant to Rule 12b-1
under  the  1940  Act ("Rule  12b-1  Plan")  continues in  effect,  any expenses
incurred by the Distributor hereunder may  be paid in accordance with the  terms
of such Rule 12b-1 Plan.
 
    (c)  Each Fund shall pay the filing  fees, and, if necessary or advisable in
connection therewith, bear  the cost and  expense of qualifying  each Fund as  a
broker  or dealer, in such states of the United States or other jurisdictions as
shall be  selected by  the Fund  and the  Distributor pursuant  to Section  5(c)
hereof  and the cost and  expenses payable to each  such state for continuing to
offer Shares  therein  until the  Fund  decides to  discontinue  selling  Shares
pursuant to Section 5(c) hereof.
 
    SECTION 9.  INDEMNIFICATION.
 
    (a)  Each Fund  shall indemnify and  hold harmless the  Distributor and each
person, if any, who controls the Distributor against any loss, liability, claim,
damage or expense (including the  reasonable cost of investigating or  defending
any  alleged loss,  liability, claim, damage  or expense  and reasonable counsel
fees incurred in connection therewith) arising by reason of any person acquiring
any Shares, which may be based upon the 1933 Act, or on any other statute or  at
common  law, on the ground that the Registration Statement or related Prospectus
and Statement  of Additional  Information,  as from  time  to time  amended  and
supplemented,  or  the annual  or  interim reports  to  shareholders of  a Fund,
includes an untrue statement  of a material  fact or omits  to state a  material
fact  required to be stated therein or necessary in order to make the statements
therein not misleading, unless such statement  or omission was made in  reliance
upon, and in
 
                                       4
<PAGE>
conformity with, information furnished to the Fund in connection therewith by or
on  behalf of  the Distributor; provided,  however, that  in no case  (i) is the
indemnity of a Fund in favor of the Distributor and any such controlling persons
to be deemed to protect the Distributor or any such controlling persons  thereof
against any liability to a Fund or its security holders to which the Distributor
or  any such controlling persons would otherwise be subject by reason of willful
misfeasance, bad faith or gross negligence  in the performance of its duties  or
by  reason  of  reckless disregard  of  its  obligations and  duties  under this
Agreement; or  (ii)  is  a Fund  to  be  liable under  its  indemnity  agreement
contained  in  this  paragraph  with  respect  to  any  claim  made  against the
Distributor or any such controlling persons, unless the Distributor or any  such
controlling persons, as the case may be, shall have notified the Fund in writing
within  a reasonable time after the summons  or other first legal process giving
information of  the  nature  of  the  claim shall  have  been  served  upon  the
Distributor  or  uch  controlling  persons (or  after  the  Distributor  or such
controlling persons shall have received notice of such service on any designated
agent), but failure to notify  the Fund of any such  claim shall not relieve  it
from  any liability which it may have to  the person against whom such action is
brought otherwise than on account of  its indemnity agreement contained in  this
paragraph.  Each Fund will be entitled to  participate at its own expense in the
defense, or, if it so elects, to assume the defense, of any such suit brought to
enforce any such liability,  but if a  Fund elects to  assume the defense,  such
defense  shall be  conducted by  counsel chosen  by it  and satisfactory  to the
Distributor or such controlling  person or persons,  defendant or defendants  in
the  suit. In the event the  Fund elects to assume the  defense of any such suit
and retain such counsel, the Distributor or such controlling person or  persons,
defendant  or defendants in  the suit, shall  bear the fees  and expenses of any
additional counsel retained by  them, but, in  case the Fund  does not elect  to
assume  the defense of any such suit,  it will reimburse the Distributor or such
controlling person or  persons, defendant  or defendants  in the  suit, for  the
reasonable  fees and expenses of  any counsel retained by  them. Each Fund shall
promptly notify  the  Distributor  of  the commencement  of  any  litigation  or
proceedings  against  it  or  any  of  its  officers  or  Directors/Trustees  in
connection with the issuance or sale of the Shares.
 
    (b)  (i)  The Distributor shall  indemnify and hold  harmless each Fund  and
each  of  its Directors/Trustees  and  officers  and  each  person, if  any, who
controls the  Fund  against  any  loss, liability,  claim,  damage,  or  expense
described in the indemnity contained in subsection (a) of this Section, but only
with respect to statements or omissions made in reliance upon, and in conformity
with,  information  furnished  to a  Fund  in writing  by  or on  behalf  of the
Distributor for use  in connection  with the Registration  Statement or  related
Prospectus  and  Statement  of  Additional Information,  as  from  time  to time
amended, or the annual or interim reports to shareholders.
 
        (ii) The Distributor  shall indemnify  and hold harmless  each Fund  and
each  Fund's  transfer agent,  individually and  in its  capacity as  the Fund's
transfer agent, from and against any claims, damages and liabilities which arise
as a result of actions taken pursuant to instructions from, or on behalf of, the
Distributor to: (1) redeem  all or a  part of shareholder  accounts in the  Fund
pursuant  to Section 4(g) hereof and pay the proceeds to, or as directed by, the
Distributor for the account  of each shareholder whose  Shares are so  redeemed;
and  (2) register Shares in the names of investors, confirm the issuance thereof
and receive payment therefor pursuant to Section 3(e) hereof.
 
       (iii) In case any action shall be brought against a Fund or any person so
indemnified by this  Section 9(b) in  respect of which  indemnity may be  sought
against  the Distributor, the Distributor shall have the rights and duties given
to a Fund, and the Fund and each person so indemnified shall have the rights and
duties given to  the Distributor, by  the provisions of  subsection (a) of  this
Section 9.
 
    (c)  If the indemnification provided for in this Section 9 is unavailable or
insufficient to hold harmless an indemnified  party under subsection (a) or  (b)
above  in respect  of any losses,  claims, damages, liabilities  or expenses (or
actions in respect thereof)  referred to herein,  then each indemnifiying  party
shall  contribute to the amount  paid or payable by  such indemnified party as a
result of such losses, claims, damages,  liabilities or expenses (or actions  in
respect  thereof) in such  proportion as is appropriate  to reflect the relative
benefits received by a  Fund on the  one hand and the  Distributor on the  other
from  the offering of  the Shares. If,  however, the allocation  provided by the
immediately preceding sentence  is not  permitted by applicable  law, then  each
indemnifying  party  shall contribute  to such  amount paid  or payable  by such
indemnified party in
 
                                       5
<PAGE>
such proportion as is appropriate to reflect not only such relative benefits but
also the relative fault  of a Fund on  the one hand and  the Distributor on  the
other  in connection  with the  statements or  omissions which  resulted in such
losses,  claims,  damages,  liabilities  or  expenses  (or  actions  in  respect
thereof),  as well as any other  relevant equitable considerations. The relative
benefits received by a  Fund on the  one hand and the  Distributor on the  other
shall  be deemed to be in the same proportion as the total net proceeds from the
offering (before deducting  expenses) received  by the  Fund bear  to the  total
compensation  received by  the Distributor,  in each  case as  set forth  in the
Prospectus. The relative fault shall be determined by reference to, among  other
things, whether the untrue or alleged untrue statement of a material fact or the
omission  or alleged  omission to state  a material fact  relates to information
supplied by  a  Fund  or  the Distributor  and  the  parties'  relative  intent,
knowledge,  access to  information and  opportunity to  correct or  prevent such
statement or omission. Each Fund and the Distributor agree that it would not  be
just  and equitable if contribution were determined by pro rata allocation or by
any other method of  allocation which does not  take into account the  equitable
considerations  referred to above. The amount  paid or payable by an indemnified
party as a result  of the losses, claims,  damages, liabilities or expenses  (or
actions  in respect thereof)  referred to above  shall be deemed  to include any
legal or  other  expenses  reasonably  incurred by  such  indemnified  party  in
connection  with investigating or defending  any such claim. Notwithstanding the
provisions of this  subsection (c),  the Distributor  shall not  be required  to
contribute  any amount in excess of the amount by which the total price at which
the Shares distributed by it  to the public were  offered to the public  exceeds
the  amount of any damages which it has otherwise been required to pay by reason
of such untrue or alleged untrue  statement or omission or alleged omission.  No
person  guilty of  fraudulent misrepresentation  (within the  meaning of Section
11(f) of the 1933 Act) shall be entitled to contribution from any person who was
not guilty of such fraudulent misrepresentation.
 
    SECTION 10.   DURATION AND TERMINATION  OF THIS AGREEMENT.   This  Agreement
shall become effective with respect to a Fund as of the date first above written
and shall remain in force until April 30, 1998, and thereafter, but only so long
as  such continuance is specifically approved at least annually by (i) the Board
of Directors/Trustees  of  each Fund,  or  by the  vote  of a  majority  of  the
outstanding  voting securities of the Fund, cast in person or by proxy, and (ii)
a majority of those Directors/Trustees who are not parties to this Agreement  or
interested  persons  of  any such  party  and  who have  no  direct  or indirect
financial interest in  this Agreement  or in the  operation of  the Fund's  Rule
12b-1  Plan or  in any agreement  related thereto,  cast in person  at a meeting
called for the purpose of voting upon such approval.
 
    This Agreement may  be terminated  at any time  without the  payment of  any
penalty,   by  the   Directors/Trustees  of  a  Fund,   by  a  majority  of  the
Directors/Trustees of a Fund who are not interested persons of the Fund and  who
have no direct or indirect financial interest in this Agreement, or by vote of a
majority  of the outstanding voting securities of a Fund, or by the Distributor,
on sixty  days'  written  notice  to  the  other  party.  This  Agreement  shall
automatically terminate in the event of its assignment.
 
    The  terms  "vote  of  a majority  of  the  outstanding  voting securities,"
"assignment" and "interested person,"  when used in  this Agreement, shall  have
the respective meanings specified in the 1940 Act.
 
    SECTION 11.  AMENDMENTS OF THIS AGREEMENT.  This Agreement may be amended by
the  parties  only  if  such  amendment  is  specifically  approved  by  (i) the
Directors/Trustees of a Fund, or by the vote of a majority of outstanding voting
securities of a Fund, and (ii) a majority of those Directors/Trustees of a  Fund
who  are not parties to  this Agreement or interested  persons of any such party
and who have no direct  or indirect financial interest  in this Agreement or  in
any Agreement related to the Fund's Rule 12b-1 Plan, cast in person at a meeting
called for the purpose of voting on such approval.
 
    SECTION  12.   ADDITIONAL FUNDS.   If  at any  time another  Fund desires to
appoint the Distributor as its principal underwriter and distributor under  this
Agreement,  it shall  notify the Distributor  in writing. If  the Distributor is
willing to serve as the Fund's principal underwriter and distributor under  this
Agreement,  it shall notify the Fund in writing, whereupon such other Fund shall
become a Fund hereunder.
 
                                       6
<PAGE>
    SECTION 13.  GOVERNING LAW.  This Agreement shall be construed in accordance
with the law of the State of New York and the applicable provisions of the  1940
Act.  To the extent the applicable  law of the State of  New York, or any of the
provisions herein, conflicts with the applicable provisions of the 1940 Act, the
latter shall control.
 
    SECTION 14.  PERSONAL LIABILITY.  With respect to any Fund that is organized
as an  unincorporated business  trust  under the  laws  of the  Commonwealth  of
Massachusetts,  its Declaration of the Trust  (each, a "Declaration") is on file
in the  office of  the  Secretary of  the  Commonwealth of  Massachusetts.  Each
Declaration  provides that the name of the Fund refers to the Trustees under the
Declaration collectively as Trustees, but not as individuals or personally;  and
no Trustee, shareholder, officer, employee or agent of any Fund shall be held to
any  personal liability, nor shall  resort be had to  their private property for
the satisfaction of any obligation or claim or otherwise, in connection with the
affairs of any Fund, but the Trust Estate only shall be liable.
 
    IN WITNESS  WHEREOF, the  parties hereto  have executed  and delivered  this
Agreement as of the day and year first written in New York, New York.
 
                                          ON BEHALF OF THE FUNDS SET FORTH ON
                                          SCHEDULE A, ATTACHED HERETO
 
                                          By: ..................................
 
                                          DEAN WITTER DISTRIBUTORS INC.
 
                                          By: ..................................
 
                                       7
<PAGE>
                               DEAN WITTER FUNDS
                             DISTRIBUTION AGREEMENT
                                   SCHEDULE A
                                AT MAY 31, 1997
 
           
                    
1)         Dean Witter American Value Fund
2)         Dean Witter Balanced Growth Fund
3)         Dean Witter Balanced Income Fund
4)         Dean Witter California Tax-Free Income Fund
5)         Dean Witter Capital Appreciation Fund
6)         Dean Witter Capital Growth Securities
7)         Dean Witter Convertible Securities Trust
8)         Dean Witter Developing Growth Securities Trust
9)         Dean Witter Diversified Income Trust
10)        Dean Witter Dividend Growth Securities Inc.
11)        Dean Witter European Growth Fund Inc.
12)        Dean Witter Federal Securities Trust
13)        Dean Witter Financial Services Trust
14)        Dean Witter Global Asset Allocation Fund
15)        Dean Witter Global Dividend Growth Securities
16)        Dean Witter Global Utilities Fund
17)        Dean Witter Health Sciences Trust
18)        Dean Witter High Yield Securities Inc.
19)        Dean Witter Income Builder Fund
20)        Dean Witter Information Fund
21)        Dean Witter Intermediate Income Securities
22)        Dean Witter International SmallCap Fund
23)        Dean Witter Japan Fund
24)        Dean Witter Managers' Select Fund
25)        Dean Witter Market Leader Trust
26)        Dean Witter Mid-Cap Growth Fund
27)        Dean Witter Natural Resource Development Securities Inc.
28)        Dean Witter New York Tax-Free Income Fund
29)        Dean Witter Pacific Growth Fund Inc.
30)        Dean Witter Precious Metals and Minerals Trust
31)        Dean Witter Special Value Fund
32)        Dean Witter Strategist Fund
33)        Dean Witter Tax-Exempt Securities Trust
34)        Dean Witter U.S. Government Securities Trust
35)        Dean Witter Utilities Fund
36)        Dean Witter Value-Added Market Series/Equity Portfolio
37)        Dean Witter World Wide Income Trust
38)        Dean Witter World Wide Investment Trust
            
 
                                       8

<PAGE>
                               DEAN WITTER FUNDS

                             DISTRIBUTION AGREEMENT
 
    AGREEMENT made as of this 28th day of July, 1997 between each of the
open-end investment companies to which Dean Witter InterCapital Inc. acts as
investment manager, that are listed on Schedule A, as may be amended from time
to time (each, a "Fund" and collectively, the "Funds"), and Dean Witter
Distributors Inc., a Delaware corporation (the "Distributor").
 
                              W I T N E S S E T H:
 
    WHEREAS, each Fund is registered as an open-end investment company under the
Investment Company Act of 1940, as amended (the "1940 Act"), and it is in the
interest of each Fund to offer its shares for sale continuously, and
 
    WHEREAS, each Fund and the Distributor wish to enter into an agreement with
each other with respect to the continuous offering of each Fund's transferable
shares, of $0.01 par value (the "Shares"), to commence on the date listed above,
in order to promote the growth of each Fund and facilitate the distribution of
its shares.
 
    NOW, THEREFORE, the parties agree as follows:
 
    SECTION 1.  APPOINTMENT OF THE DISTRIBUTOR.
 
    (a) Each Fund hereby appoints the Distributor as the principal underwriter
and distributor of the Fund to sell Shares to the public on the terms set forth
in this Agreement and that Fund's prospectus and the Distributor hereby accepts
such appointment and agrees to act hereunder. Each Fund, during the term of this
Agreement, shall sell Shares to the Distributor upon the terms and conditions
set forth herein.
 
    (b) The Distributor agrees to purchase Shares, as principal for its own
account, from each Fund and to sell Shares as principal to investors, and
securities dealers, including Dean Witter Reynolds Inc. ("DWR"), an affiliate of
the Distributor, upon the terms described herein and in that Fund's prospectus
(the "Prospectus") and statement of additional information included in the
Fund's registration statement (the "Registration Statement") most recently filed
from time to time with the Securities and Exchange Commission (the "SEC") and
effective under the Securities Act of 1933, as amended (the "1933 Act"), and the
1940 Act or as the Prospectus may be otherwise amended or supplemented and filed
with the SEC pursuant to Rule 497 under the 1933 Act.
 
    SECTION 2.  EXCLUSIVE NATURE OF DUTIES.  The Distributor shall be the
exclusive principal underwriter and distributor of each Fund, except that the
exclusive rights granted to the Distributor to sell the Shares shall not apply
to Shares issued by each Fund: (i) in connection with the merger or
consolidation of any other investment company or personal holding company with
the Fund or the acquisition by purchase or otherwise of all (or substantially
all) the assets or the outstanding shares of any such company by the Fund; (ii)
pursuant to reinvestment of dividends or capital gains distributions; or (iii)
pursuant to the reinstatement privilege afforded redeeming shareholders.
 
    SECTION 3.  PURCHASE OF SHARES FROM EACH FUND.  The Shares are offered in
four classes (each, a "Class"), as described in the Prospectus, as amended or
supplemented from time to time.
 
    (a) The Distributor shall have the right to buy from each Fund the Shares of
the particular class needed, but not more than the Shares needed (except for
clerical errors in transmission), to fill unconditional orders for Shares of the
applicable class placed with the Distributor by investors or securities dealers.
The price which the Distributor shall pay for the Shares so purchased from the
Fund shall be the net asset value, determined as set forth in the Prospectus,
used in determining the public offering price on which such orders were based.
 
    (b) The Shares are to be resold by the Distributor at the public offering
price of Shares of the applicable class as set forth in the Prospectus, to
investors or to securities dealers, including DWR, who
 
                                       1
<PAGE>
have entered into selected dealer agreements with the Distributor upon the terms
and conditions set forth in Section 7 hereof ("Selected Dealers").
 
    (c) Each Fund shall have the right to suspend the sale of the Shares at
times when redemption is suspended pursuant to the conditions set forth in
Section 4(f) hereof. Each Fund shall also have the right to suspend the sale of
the Shares if trading on the New York Stock Exchange shall have been suspended,
if a banking moratorium shall have been declared by federal or New York
authorities, or if there shall have been some other extraordinary event which,
in the judgment of a Fund, makes it impracticable to sell its Shares.
 
    (d) Each Fund, or any agent of a Fund designated in writing by the Fund,
shall be promptly advised of all purchase orders for Shares received by the
Distributor. Any order may be rejected by a Fund; provided, however, that a Fund
will not arbitrarily or without reasonable cause refuse to accept orders for the
purchase of Shares. The Distributor will confirm orders upon their receipt, and
each Fund (or its agent) upon receipt of payment therefor and instructions will
deliver share certificates for such Shares or a statement confirming the
issuance of Shares. Payment shall be made to the Fund in New York Clearing House
funds. The Distributor agrees to cause such payment and such instructions to be
delivered promptly to the Fund (or its agent).
 
    (e) With respect to Shares sold by any Selected Dealer, the Distributor is
authorized to direct each Fund's transfer agent to receive instructions directly
from the Selected Dealer on behalf of the Distributor as to registration of
Shares in the names of investors and to confirm issuance of the Shares to such
investors. The Distributor is also authorized to instruct the transfer agent to
receive payment directly from the Selected Dealer on behalf of the Distributor,
for prompt transmittal to each Fund's custodian, of the purchase price of the
Shares. In such event the Distributor shall obtain from the Selected Dealer and
maintain a record of such registration instructions and payments.
 
    SECTION 4.  REPURCHASE OR REDEMPTION OF SHARES.
 
    (a) Any of the outstanding Shares of a Fund may be tendered for redemption
at any time, and each Fund agrees to redeem its Shares so tendered in accordance
with the applicable provisions set forth in its Prospectus. The price to be paid
to redeem the Shares shall be equal to the net asset value determined as set
forth in the Prospectus less any applicable contingent deferred sales charge
("CDSC"). Upon any redemption of Shares the Fund shall pay the total amount of
the redemption price in New York Clearing House funds in accordance with
applicable provisions of the Prospectus.
 
    (b) The redemption by a Fund of any of its Class A Shares purchased by or
through the Distributor will not affect the applicable front-end sales charge
secured by the Distributor or any Selected Dealer in the course of the original
sale, except that if any Class A Shares are tendered for redemption within seven
business days after the date of the confirmation of the original purchase, the
right to the applicable front-end sales charge shall be forfeited by the
Distributor and the Selected Dealer which sold such Shares.
 
    (c) The proceeds of any redemption of Class A, Class B or Class C Shares
shall be paid by each Fund as follows: (i) any applicable CDSC shall be paid to
the Distributor or to the Selected Dealer, or, when applicable, pursuant to the
Rules of the Association of the National Association of Securities Dealers, Inc.
("NASD"), retained by the Fund and (ii) the balance shall be paid to the
redeeming shareholders, in each case in accordance with applicable provisions of
its Prospectus in New York Clearing House funds. The Distributor is authorized
to direct a Fund to pay directly to the Selected Dealer any CDSC payable by a
Fund to the Distributor in respect of Class A, Class B, or Class C Shares sold
by the Selected Dealer to the redeeming shareholders.
 
    (d) The Distributor is authorized, as agent for the Fund, to repurchase
Shares, represented by a share certificate which is delivered to any office of
the Distributor in accordance with applicable provisions set forth in each
Fund's Prospectus. The Distributor shall promptly transmit to the transfer agent
of the Fund for redemption all Shares so delivered. The Distributor shall be
responsible for the accuracy of instructions transmitted to the Fund's transfer
agent in connection with all such repurchases.
 
                                       2
<PAGE>
    (e) The Distributor is authorized, as agent for each Fund, to repurchase
Shares held in a shareholder's account with a Fund for which no share
certificate has been issued, upon the telephonic request of the shareholders, or
at the discretion of the Distributor. The Distributor shall promptly transmit to
the transfer agent of the Fund, for redemption, all such orders for repurchase
of Shares. Payment for Shares repurchased may be made by a Fund to the
Distributor for the account of the shareholder. The Distributor shall be
responsible for the accuracy of instructions transmitted to the Fund's transfer
agent in connection with all such repurchases.
 
    (f) Redemption of its Shares or payment by a Fund may be suspended at times
when the New York Stock Exchange is closed, when trading on said Exchange is
restricted, when an emergency exists as a result of which disposal by a Fund of
securities owned by it is not reasonably practicable or it is not reasonably
practicable for a Fund fairly to determine the value of its net assets, or
during any other period when the SEC, by order, so permits.
 
    (g) With respect to its Shares tendered for redemption or repurchase by any
Selected Dealer on behalf of its customers, the Distributor is authorized to
instruct the transfer agent of a Fund to accept orders for redemption or
repurchase directly from the Selected Dealer on behalf of the Distributor and to
instruct the Fund to transmit payments for such redemptions and repurchases
directly to the Selected Dealer on behalf of the Distributor for the account of
the shareholder. The Distributor shall obtain from the Selected Dealer, and
shall maintain, a record of such orders. The Distributor is further authorized
to obtain from the Fund, and shall maintain, a record of payment made directly
to the Selected Dealer on behalf of the Distributor.
 
    SECTION 5.  DUTIES OF THE FUND.
 
    (a) Each Fund shall furnish to the Distributor copies of all information,
financial statements and other papers which the Distributor may reasonably
request for use in connection with the distribution of its Shares, including one
certified copy, upon request by the Distributor, of all financial statements
prepared by the Fund and examined by independent accountants. Each Fund shall,
at the expense of the Distributor, make available to the Distributor such number
of copies of its Prospectus as the Distributor shall reasonably request.
 
    (b) Each Fund shall take, from time to time, but subject to the necessary
approval of its shareholders, all necessary action to fix the number of its
authorized Shares and to register Shares under the 1933 Act, to the end that
there will be available for sale such number of Shares as investors may
reasonably be expected to purchase.
 
    (c) Each Fund shall use its best efforts to pay the filing fees for an
appropriate number of its Shares to be sold under the securities laws of such
states as the Distributor and the Fund may approve. Any qualification to sell
its Shares in a state may be withheld, terminated or withdrawn by a Fund at any
time in its discretion. As provided in Section 8(c) hereof, such filing fees
shall be paid by the Fund. The Distributor shall furnish any information and
other material relating to its affairs and activities as may be required by a
Fund in connection with the sale of its Shares in any state.
 
    (d) Each Fund shall, at the expense of the Distributor, furnish, in
reasonable quantities upon request by the Distributor, copies of its annual and
interim reports.
 
    SECTION 6.  DUTIES OF THE DISTRIBUTOR.
 
    (a) The Distributor shall sell shares of each Fund through DWR and may sell
shares through other securities dealers and its own Account Executives, and
shall devote reasonable time and effort to promote sales of the Shares, but
shall not be obligated to sell any specific number of Shares. The services of
the Distributor hereunder are not exclusive and it is understood that the
Distributor may act as principal underwriter for other registered investment
companies, so long as the performance of its obligations hereunder is not
impaired thereby. It is also understood that Selected Dealers, including DWR,
may also sell shares for other registered investment companies.
 
                                       3
<PAGE>
    (b) Neither the Distributor nor any Selected Dealer shall give any
information or make any representations, other than those contained in the
Registration Statement or related Prospectus and any sales literature
specifically approved by the appropriate Fund.
 
    (c) The Distributor agrees that it will at all times comply with the
applicable terms and limitations of the Rules of the Association of the NASD.
 
    SECTION 7.  SELECTED DEALERS AGREEMENTS.
 
    (a) The Distributor shall have the right to enter into selected dealer
agreements with Selected Dealers for the sale of Shares. In making agreements
with Selected Dealers, the Distributor shall act only as principal and not as
agent for a Fund. Shares sold to Selected Dealers shall be for resale by such
dealers only at the public offering price set forth in the Prospectus. With
respect to Class A Shares, in such agreement the Distributor shall have the
right to fix the portion of the applicable front-end sales charge which may be
allocated to the Selected Dealers.
 
    (b) Within the United States, the Distributor shall offer and sell Shares
only to Selected Dealers that are members in good standing of the NASD.
 
    (c) The Distributor shall adopt and follow procedures, as approved by each
Fund, for the confirmation of sales of its Shares to investors and Selected
Dealers, the collection of amounts payable by investors and Selected Dealers on
such sales, and the cancellation of unsettled transactions, as may be necessary
to comply with the requirements of the NASD, as such requirements may from time
to time exist.
 
    SECTION 8.  PAYMENT OF EXPENSES.
 
    (a) Each Fund shall bear all costs and expenses of the Fund, including fees
and disbursements of legal counsel including counsel to the Directors/Trustees
of each Fund who are not interested persons (as defined in the 1940 Act) of the
Fund or the Distributor, and independent accountants, in connection with the
preparation and filing of any required Registration Statements and Prospectuses
and all amendments and supplements thereto, and the expense of preparing,
printing, mailing and otherwise distributing prospectuses and statements of
additional information, annual or interim reports or proxy materials to
shareholders.
 
    (b) The Distributor shall bear all expenses incurred by it in connection
with its duties and activities under this Agreement including the payment to
Selected Dealers of any sales commissions, service fees and other expenses for
sales of a Fund's Shares (except such expenses as are specifically undertaken
herein by a Fund) incurred or paid by Selected Dealers, including DWR. The
Distributor shall bear the costs and expenses of preparing, printing and
distributing any supplementary sales literature used by the Distributor or
furnished by it for use by Selected Dealers in connection with the offering of
the Shares for sale. Any expenses of advertising incurred in connection with
such offering will also be the obligation of the Distributor. It is understood
and agreed that, so long as a Fund's Plan of Distribution pursuant to Rule 12b-1
under the 1940 Act ("Rule 12b-1 Plan") continues in effect, any expenses
incurred by the Distributor hereunder may be paid in accordance with the terms
of such Rule 12b-1 Plan.
 
    (c) Each Fund shall pay the filing fees, and, if necessary or advisable in
connection therewith, bear the cost and expense of qualifying each Fund as a
broker or dealer, in such states of the United States or other jurisdictions as
shall be selected by the Fund and the Distributor pursuant to Section 5(c)
hereof and the cost and expenses payable to each such state for continuing to
offer Shares therein until the Fund decides to discontinue selling Shares
pursuant to Section 5(c) hereof.
 
    SECTION 9.  INDEMNIFICATION.
 
    (a) Each Fund shall indemnify and hold harmless the Distributor and each
person, if any, who controls the Distributor against any loss, liability, claim,
damage or expense (including the reasonable cost of investigating or defending
any alleged loss, liability, claim, damage or expense and reasonable counsel
fees incurred in connection therewith) arising by reason of any person acquiring
any Shares, which may be based upon the 1933 Act, or on any other statute or at
common law, on the ground that the Registration Statement or related Prospectus
and Statement of Additional Information, as from time to time amended
 
                                       4
<PAGE>
and supplemented, or the annual or interim reports to shareholders of a Fund,
includes an untrue statement of a material fact or omits to state a material
fact required to be stated therein or necessary in order to make the statements
therein not misleading, unless such statement or omission was made in reliance
upon, and in conformity with, information furnished to the Fund in connection
therewith by or on behalf of the Distributor; provided, however, that in no case
(i) is the indemnity of a Fund in favor of the Distributor and any such
controlling persons to be deemed to protect the Distributor or any such
controlling persons thereof against any liability to a Fund or its security
holders to which the Distributor or any such controlling persons would otherwise
be subject by reason of willful misfeasance, bad faith or gross negligence in
the performance of its duties or by reason of reckless disregard of its
obligations and duties under this Agreement; or (ii) is a Fund to be liable
under its indemnity agreement contained in this paragraph with respect to any
claim made against the Distributor or any such controlling persons, unless the
Distributor or any such controlling persons, as the case may be, shall have
notified the Fund in writing within a reasonable time after the summons or other
first legal process giving information of the nature of the claim shall have
been served upon the Distributor or uch controlling persons (or after the
Distributor or such controlling persons shall have received notice of such
service on any designated agent), but failure to notify the Fund of any such
claim shall not relieve it from any liability which it may have to the person
against whom such action is brought otherwise than on account of its indemnity
agreement contained in this paragraph. Each Fund will be entitled to participate
at its own expense in the defense, or, if it so elects, to assume the defense,
of any such suit brought to enforce any such liability, but if a Fund elects to
assume the defense, such defense shall be conducted by counsel chosen by it and
satisfactory to the Distributor or such controlling person or persons, defendant
or defendants in the suit. In the event the Fund elects to assume the defense of
any such suit and retain such counsel, the Distributor or such controlling
person or persons, defendant or defendants in the suit, shall bear the fees and
expenses of any additional counsel retained by them, but, in case the Fund does
not elect to assume the defense of any such suit, it will reimburse the
Distributor or such controlling person or persons, defendant or defendants in
the suit, for the reasonable fees and expenses of any counsel retained by them.
Each Fund shall promptly notify the Distributor of the commencement of any
litigation or proceedings against it or any of its officers or
Directors/Trustees in connection with the issuance or sale of the Shares.
 
    (b) (i) The Distributor shall indemnify and hold harmless each Fund and each
of its Directors/Trustees and officers and each person, if any, who controls
the Fund against any loss, liability, claim, damage, or expense described in the
indemnity contained in subsection (a) of this Section, but only with respect to
statements or omissions made in reliance upon, and in conformity with,
information furnished to a Fund in writing by or on behalf of the Distributor
for use in connection with the Registration Statement or related Prospectus and
Statement of Additional Information, as from time to time amended, or the annual
or interim reports to shareholders.
 
        (ii) The Distributor shall indemnify and hold harmless each Fund and
each Fund's transfer agent, individually and in its capacity as the Fund's
transfer agent, from and against any claims, damages and liabilities which arise
as a result of actions taken pursuant to instructions from, or on behalf of, the
Distributor to: (1) redeem all or a part of shareholder accounts in the Fund
pursuant to Section 4(g) hereof and pay the proceeds to, or as directed by, the
Distributor for the account of each shareholder whose Shares are so redeemed;
and (2) register Shares in the names of investors, confirm the issuance thereof
and receive payment therefor pursuant to Section 3(e) hereof.
 
        (iii) In case any action shall be brought against a Fund or any person
so indemnified by this Section 9(b) in respect of which indemnity may be sought
against the Distributor, the Distributor shall have the rights and duties given
to a Fund, and the Fund and each person so indemnified shall have the rights and
duties given to the Distributor, by the provisions of subsection (a) of this
Section 9.
 
    (c) If the indemnification provided for in this Section 9 is unavailable or
insufficient to hold harmless an indemnified party under subsection (a) or (b)
above in respect of any losses, claims, damages, liabilities or expenses (or
actions in respect thereof) referred to herein, then each indemnifiying party
shall contribute to the amount paid or payable by such indemnified party as a
result of such losses, claims, damages, liabilities or expenses (or actions in
respect thereof) in such proportion as is appropriate to reflect the relative
benefits received by a Fund on the one hand and the Distributor on the other
from the
 
                                       5
<PAGE>
offering of the Shares. If, however, the allocation provided by the immediately
preceding sentence is not permitted by applicable law, then each indemnifying
party shall contribute to such amount paid or payable by such indemnified party
in such proportion as is appropriate to reflect not only such relative benefits
but also the relative fault of a Fund on the one hand and the Distributor on the
other in connection with the statements or omissions which resulted in such
losses, claims, damages, liabilities or expenses (or actions in respect
thereof), as well as any other relevant equitable considerations. The relative
benefits received by a Fund on the one hand and the Distributor on the other
shall be deemed to be in the same proportion as the total net proceeds from the
offering (before deducting expenses) received by the Fund bear to the total
compensation received by the Distributor, in each case as set forth in the
Prospectus. The relative fault shall be determined by reference to, among other
things, whether the untrue or alleged untrue statement of a material fact or the
omission or alleged omission to state a material fact relates to information
supplied by a Fund or the Distributor and the parties' relative intent,
knowledge, access to information and opportunity to correct or prevent such
statement or omission. Each Fund and the Distributor agree that it would not be
just and equitable if contribution were determined by pro rata allocation or by
any other method of allocation which does not take into account the equitable
considerations referred to above. The amount paid or payable by an indemnified
party as a result of the losses, claims, damages, liabilities or expenses (or
actions in respect thereof) referred to above shall be deemed to include any
legal or other expenses reasonably incurred by such indemnified party in
connection with investigating or defending any such claim. Notwithstanding the
provisions of this subsection (c), the Distributor shall not be required to
contribute any amount in excess of the amount by which the total price at which
the Shares distributed by it to the public were offered to the public exceeds
the amount of any damages which it has otherwise been required to pay by reason
of such untrue or alleged untrue statement or omission or alleged omission. No
person guilty of fraudulent misrepresentation (within the meaning of Section
11(f) of the 1933 Act) shall be entitled to contribution from any person who was
not guilty of such fraudulent misrepresentation.
 
    SECTION 10.  DURATION AND TERMINATION OF THIS AGREEMENT.  This Agreement
shall become effective with respect to a Fund as of the date first above written
and shall remain in force until April 30, 1998, and thereafter, but only so long
as such continuance is specifically approved at least annually by (i) the Board
of Directors/Trustees of each Fund, or by the vote of a majority of the
outstanding voting securities of the Fund, cast in person or by proxy, and (ii)
a majority of those Directors/Trustees who are not parties to this Agreement or
interested persons of any such party and who have no direct or indirect
financial interest in this Agreement or in the operation of the Fund's Rule
12b-1 Plan or in any agreement related thereto, cast in person at a meeting
called for the purpose of voting upon such approval.
 
    This Agreement may be terminated at any time without the payment of any
penalty, by the Directors/Trustees of a Fund, by a majority of the
Directors/Trustees of a Fund who are not interested persons of the Fund and who
have no direct or indirect financial interest in this Agreement, or by vote of a
majority of the outstanding voting securities of a Fund, or by the Distributor,
on sixty days' written notice to the other party. This Agreement shall
automatically terminate in the event of its assignment.
 
    The terms "vote of a majority of the outstanding voting securities,"
"assignment" and "interested person," when used in this Agreement, shall have
the respective meanings specified in the 1940 Act.
 
    SECTION 11.  AMENDMENTS OF THIS AGREEMENT.  This Agreement may be amended by
the parties only if such amendment is specifically approved by (i) the
Directors/Trustees of a Fund, or by the vote of a majority of outstanding voting
securities of a Fund, and (ii) a majority of those Directors/Trustees of a Fund
who are not parties to this Agreement or interested persons of any such party
and who have no direct or indirect financial interest in this Agreement or in
any Agreement related to the Fund's Rule 12b-1 Plan, cast in person at a meeting
called for the purpose of voting on such approval.
 
    SECTION 12.  ADDITIONAL FUNDS.  If at any time another Fund desires to
appoint the Distributor as its principal underwriter and distributor under this
Agreement, it shall notify the Distributor in writing. If the Distributor is
willing to serve as the Fund's principal underwriter and distributor under this
Agreement, it shall notify the Fund in writing, whereupon such other Fund shall
become a Fund hereunder.
 
    SECTION 13.  GOVERNING LAW.  This Agreement shall be construed in accordance
with the law of the State of New York and the applicable provisions of the 1940
Act. To the extent the applicable law of the
 
                                       6
<PAGE>
State of New York, or any of the provisions herein, conflicts with the
applicable provisions of the 1940 Act, the latter shall control.
 
    SECTION 14.  PERSONAL LIABILITY.  With respect to any Fund that is organized
as an unincorporated business trust under the laws of the Commonwealth of
Massachusetts, its Declaration of the Trust (each, a "Declaration") is on file
in the office of the Secretary of the Commonwealth of Massachusetts. Each
Declaration provides that the name of the Fund refers to the Trustees under the
Declaration collectively as Trustees, but not as individuals or personally; and
no Trustee, shareholder, officer, employee or agent of any Fund shall be held to
any personal liability, nor shall resort be had to their private property for
the satisfaction of any obligation or claim or otherwise, in connection with the
affairs of any Fund, but the Trust Estate only shall be liable.
 
    IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Agreement as of the day and year first written in New York, New York.
 
                                          ON BEHALF OF THE FUNDS SET FORTH ON
                                          SCHEDULE A, ATTACHED HERETO
 
                                          By: ..................................
 
                                          DEAN WITTER DISTRIBUTORS INC.
 
                                          By: ..................................
 
                                       7
<PAGE>
                               DEAN WITTER FUNDS
                             DISTRIBUTION AGREEMENT

                                   SCHEDULE A
                                AT JULY 28, 1997
 
         
                   
1)         Dean Witter American Value Fund
2)         Dean Witter Balanced Growth Fund
3)         Dean Witter Balanced Income Fund
4)         Dean Witter California Tax-Free Income Fund
5)         Dean Witter Capital Appreciation Fund
6)         Dean Witter Capital Growth Securities
7)         Dean Witter Convertible Securities Trust
8)         Dean Witter Developing Growth Securities Trust
9)         Dean Witter Diversified Income Trust
10)        Dean Witter Dividend Growth Securities Inc.
11)        Dean Witter European Growth Fund Inc.
12)        Dean Witter Federal Securities Trust
13)        Dean Witter Financial Services Trust
14)        Dean Witter Global Asset Allocation Fund
15)        Dean Witter Global Dividend Growth Securities
16)        Dean Witter Global Utilities Fund
17)        Dean Witter Health Sciences Trust
18)        Dean Witter High Yield Securities Inc.
19)        Dean Witter Income Builder Fund
20)        Dean Witter Information Fund
21)        Dean Witter Intermediate Income Securities
22)        Dean Witter International SmallCap Fund
23)        Dean Witter Japan Fund
24)        Dean Witter Managers' Select Fund
25)        Dean Witter Market Leader Trust
26)        Dean Witter Mid-Cap Growth Fund
27)        Dean Witter Natural Resource Development Securities Inc.
28)        Dean Witter New York Tax-Free Income Fund
29)        Dean Witter Pacific Growth Fund Inc.
30)        Dean Witter Precious Metals and Minerals Trust
31)        Dean Witter Special Value Fund
32)        Dean Witter Strategist Fund
33)        Dean Witter Tax-Exempt Securities Trust
34)        Dean Witter U.S. Government Securities Trust
35)        Dean Witter Utilities Fund
36)        Dean Witter Value-Added Market Series/Equity Portfolio
37)        Dean Witter World Wide Income Trust
38)        Dean Witter World Wide Investment Trust
           
 
                                       8

<PAGE>

CONSENT OF INDEPENDENT ACCOUNTANTS


We hereby consent to the use in the Statement of Additional Information 
constituting part of this Post-Effective Amendment No. 13 to the registration 
statement on Form N-1A (the "Registration Statement") of our report dated 
November 8, 1996, relating to the financial statements and financial 
highlights of Dean Witter Convertible Securities Trust, which appears in such 
Statement of Additional Information, and to the incorporation by reference of 
our report into the Prospectus which constitutes part of this Registration 
Statement.  We also consent to the references to us under the headings 
"Independent Accountants" and "Experts" in such Statement of Additional 
Information and to the reference to us under the heading "Financial 
Highlights" in such Prospectus.


/s/ Price Waterhouse LLP

PRICE WATERHOUSE LLP
1177 Avenue of the Americas
New York, New York 10036
July 15, 1997


<PAGE>


       AMENDED AND RESTATED PLAN OF DISTRIBUTION PURSUANT TO RULE 12b-1 
                                      OF 
                   DEAN WITTER CONVERTIBLE SECURITIES TRUST 

   WHEREAS, Dean Witter Convertible Securities Trust (the "Fund") is engaged 
in business as an open-end management investment company and is registered as 
such under the Investment Company Act of 1940, as amended (the "Act"); and 

   WHEREAS, on December 19, 1995, the Fund most recently amended and restated 
a Plan of Distribution pursuant to Rule 12b-1 under the Act which had 
initially been adopted on August 8, 1985, and the Trustees then determined 
that there was a reasonable likelihood that adoption of the Plan of 
Distribution, as then amended and restated, would benefit the Fund and its 
shareholders; and 

   WHEREAS, the Trustees believe that continuation of said Plan of 
Distribution, as amended and restated herein, is reasonably likely to 
continue to benefit the Fund and its shareholders; and 

   WHEREAS, on August 8, 1985, the Fund and Dean Witter Reynolds Inc. ("DWR") 
entered into a Distribution Agreement pursuant to which the Fund employed DWR 
as distributor of the Fund's shares; and 

   WHEREAS, on January 4, 1993, the Fund and DWR substituted Dean Witter 
Distributors Inc. (the "Distributor") in the place of DWR as distributor of 
the Fund's shares; and 

   WHEREAS, the Fund, DWR and the Distributor intend that DWR will continue 
to promote the sale of Fund shares and provide personal services to Fund 
shareholders with respect to their holdings of Fund shares; and 

   WHEREAS, the Fund and the Distributor entered into a separate Distribution 
Agreement dated as of July 28, 1997 (which superseded a Distribution 
Agreement dated May 31, 1997, which Agreement in turn superseded an Agreement 
dated June 30, 1993), pursuant to which the Fund has employed the Distributor 
in such capacity during the continuous offering of shares of the Fund. 

   NOW, THEREFORE, the Fund hereby amends the Plan of Distribution previously 
adopted and amended and restated, and the Distributor hereby agrees to the 
terms of said Plan of Distribution (the "Plan"), as amended herein, in 
accordance with Rule 12b-1 under the Act on the following terms and 
conditions with respect to the Class A, Class B and Class C shares of the 
Fund: 

   1(a)(i). With respect to Class A and Class C shares of the Fund, the 
Distributor hereby undertakes to directly bear all costs of rendering the 
services to be performed by it under this Plan and under the Distribution 
Agreement, except for those specific expenses that the Trustees determine to 
reimburse as hereinafter set forth. 

   1(a)(ii). The Fund is hereby authorized to reimburse the Distributor, DWR, 
its affiliates and other broker-dealers for distribution expenses incurred by 
them specifically on behalf of Class A and Class C shares of the Fund. 
Reimbursement will be made through payments at the end of each month. The 
amount of each monthly payment may in no event exceed an amount equal to a 
payment at the annual rate of 0.25%, in the case of Class A, and 1.0%, in the 
case of Class C, of the average net assets of the respective Class during the 
month. With respect to Class A, in the case of all expenses other than 
expenses representing the service fee and, with respect to Class C, in the 
case of all expenses other than expenses representing a gross sales credit or 
a residual to account executives, such amounts shall be determined at the 
beginning of each calendar quarter by the Trustees, including a majority of 
the Trustees who are not "interested persons" of the Fund, as defined in the 
Act. Expenses representing the service fee (for Class A) or a gross sales 
credit or a residual to account executives (for Class C) may be reimbursed 
without prior determination. In the event that the Distributor proposes that 
monies shall be reimbursed for other than such expenses, then in making the 
quarterly determinations of the amounts that may be expended by the Fund, the 
Distributor shall provide, and the Trustees shall review, a quarterly budget 
of projected distribution expenses to be incurred by the Distributor, DWR, 
its affiliates or other broker-dealers on behalf of the Fund together with a 
report explaining the purposes and anticipated benefits of incurring 

<PAGE>

such expenses. The Trustees shall determine the particular expenses, and the 
portion thereof that may be borne by the Fund, and in making such 
determination shall consider the scope of the Distributor's commitment to 
promoting the distribution of the Fund's Class A and Class C shares directly 
or through DWR, its affiliates or other broker-dealers. 

   1(a)(iii). If, as of the end of any calendar year, the actual expenses 
incurred by the Distributor, DWR, its affiliates and other broker-dealers on 
behalf of Class A or Class C shares of the Fund (including accrued expenses 
and amounts reserved for incentive compensation and bonuses) are less than 
the amount of payments made by such Class pursuant to this Plan, the 
Distributor shall promptly make appropriate reimbursement to the appropriate 
Class. If, however, as of the end of any calendar year, the actual expenses 
(other than expenses representing a gross sales credit) of the Distributor, 
DWR, its affiliates and other broker-dealers are greater than the amount of 
payments made by Class A or Class C shares of the Fund pursuant to this Plan, 
such Class will not reimburse the Distributor, DWR, its affiliates or other 
broker-dealers for such expenses through payments accrued pursuant to this 
Plan in the subsequent fiscal year. Expenses representing a gross sales 
credit may be reimbursed in the subsequent calendar year. 

   1(b). With respect to Class B shares of the Fund, the Fund shall pay to 
the Distributor, as the distributor of securities of which the Fund is the 
issuer, compensation for distribution of its Class B shares at the rate of 
the lesser of (i) 1.0% per annum of the average daily aggregate sales of the 
Fund's Class B shares since the Fund's inception (not including reinvestment 
of dividends and capital gains distributions from the Fund) less the average 
daily aggregate net asset value of the Fund's Class B shares redeemed since 
the Fund's inception upon which a contingent deferred sales charge has been 
imposed or upon which such charge has been waived, or (ii) 1.0% per annum of 
the average daily net assets of Class B. Such compensation shall be 
calculated and accrued daily and paid monthly or at such other intervals as 
the Trustees shall determine. 

   The Distributor may direct that all or any part of the amounts receivable 
by it under this Plan be paid directly to DWR, its affiliates or other 
broker-dealers who provide distribution and shareholder services. All 
payments made hereunder pursuant to the Plan shall be in accordance with the 
terms and limitations of the Rules of the Association of the National 
Association of Securities Dealers, Inc. 

   2. With respect to expenses incurred by each Class, the amount set forth 
in paragraph 1 of this Plan shall be paid for services of the Distributor, 
DWR its affiliates and other broker-dealers it may select in connection with 
the distribution of the Fund's shares, including personal services to 
shareholders with respect to their holdings of Fund shares, and may be spend 
by the Distributor, DWR, its affiliates and such broker-dealers on any 
activities or expenses related to the distribution of the Fund's shares or 
services to shareholders, including, but not limited to: compensation to, and 
expenses of, account executives or other employees of the Distributor, DWR, 
its affiliates or other broker-dealers; overhead and other branch office 
distribution-related expenses and telephone expenses of persons who engage in 
or support distribution of shares or who provide personal services to 
shareholders; printing of prospectuses and reports for other than existing 
shareholders; preparation, printing and distribution of sales literature and 
advertising materials and, with respect to Class B, opportunity costs in 
incurring the foregoing expenses (which may be calculated as a carrying 
charge on the excess of the distribution expenses incurred by the 
Distributor, DWR, its affiliates or other broker-dealers over distribution 
revenues received by them, such excess being hereinafter referred to as 
"carryover expenses"). The overhead and other branch office 
distribution-related expenses referred to in this paragraph 2 may include: 
(a) the expenses operating the branch offices of the Distributor or other 
broker-dealers, including DWR, in connection with the sale of the Fund 
shares, including lease costs, the salaries and employee benefits of 
operations and sales support personnel, utility costs, communications costs 
and the costs of stationery and supplies; (b) the costs of client sales 
seminars; (c) travel expenses of mutual fund sales coordinators to promote 
the sale of Fund shares; and (d) other expenses relating to branch promotion 
of Fund sales. Payments may also be made with respect to distribution 
expenses incurred in connection with the distribution of shares, including 
personal services to shareholders with respect to holdings of such shares, of 
an investment company whose assets are acquired by the Fund in a tax-free 
reorganization. It is contemplated that, with respect to 


                                2           

<PAGE>

Class A shares, the entire fee set forth in paragraph 1(a) will be 
characterized as a service fee within the meaning of the National Association 
of Securities Dealers, Inc. guidelines and that, with respect to Class B and 
Class C shares, payments at the annual rate of 0.25% will be so 
characterized. 

   3. This Plan, as amended and restated, shall not take effect with respect 
to any particular Class until it has been approved, together with any related 
agreements, by votes of a majority of the Board of Trustees of the Fund and 
of the Trustees who are not "interested persons" of the Fund (as defined in 
the Act) and have no direct financial interest in the operation of this Plan 
or any agreements related to it (the "Rule 12b-1 Trustees"), cast in person 
at a meeting (or meetings) called for the purpose of voting on this Plan and 
such related agreements. 

   4. This Plan shall continue in effect with respect to each Class until 
April 30, 1998, and from year to year thereafter, provided such continuance 
is specifically approved at least annually in the manner provided for 
approval of this Plan in paragraph 3 hereof. 

   5. The Distributor shall provide to the Trustees of the Fund and the 
Trustees shall review, at least quarterly, a written report of the amounts so 
expended and the purposes for which such expenditures were made. In this 
regard, the Trustees shall request the Distributor to specify such items of 
expenses as the Trustees deem appropriate. The Trustees shall consider such 
items as they deem relevant in making the determinations required by 
paragraph 4 hereof. 

   6. This Plan may be terminated at any time with respect to a Class by vote 
of a majority of the Rule 12b-1 Trustees, or by vote of a majority of the 
outstanding voting securities of the Fund. The Plan may remain in effect with 
the respect to a particular Class even if the Plan has been terminated in 
accordance with this paragraph 6 with respect to any other Class. In the 
event of any such termination or in the event of nonrenewal, the Fund shall 
have no obligation to pay expenses which have been incurred by the 
Distributor, DWR, its affiliates or other broker-dealers in excess of 
payments made by the Fund pursuant to this Plan. However, with respect to 
Class B, this shall not preclude consideration by the Trustees of the manner 
in which such excess expenses shall be treated. 

   7. This Plan may not be amended with respect to any Class to increase 
materially the amount each Class may spend for distribution provided in 
paragraph 1 hereof unless such amendment is approved by a vote of at least a 
majority (as defined in the Act) of the outstanding voting securities of that 
Class, and no material amendment to the Plan shall be made unless approved in 
the manner provided for approval in paragraph 3 hereof. Class B shares will 
have the right to vote on any material increase in the fee set forth in 
paragraph 1(a) above affecting Class A shares. 

   8. While this Plan is in effect, the selection and nomination of Trustees 
who are not interested persons (as defined in the Act) of the Fund shall be 
committed to the discretion of the Trustees who are not interested persons. 

   9. The Fund shall preserve copies of this Plan and any related agreements 
and all reports made pursuant to paragraph 5 hereof, for a period of not less 
than six years from the date of this Plan, any such agreement or any such 
report, as the case may be, the first two years in an easily accessible 
place. 

   10. The Declaration of Trust establishing Dean Witter Convertible 
Securities Trust, dated May 21, 1985, a copy of which, together with all 
amendments thereto (the "Declaration"), is on file in the office of the 
Secretary of the Commonwealth of Massachusetts, provides that the name Dean 
Witter Convertible Securities Trust refers to the Trustees under the 
Declaration collectively as Trustees but not as individuals or personally; 
and no Trustee, shareholder, officer, employee or agent of Dean Witter 
Convertible Securities Trust shall be held to any personal liability, nor 
shall resort be had to their private property for this satisfaction of any 
obligation or claim or otherwise, in connection with the affairs of said Dean 
Witter Convertible Securities Trust, but the Trust Estate only shall be 
liable. 


                                3           

<PAGE>

   IN WITNESS WHEREOF, the Fund, the Distributor and DWR have executed this 
amended and restated Plan of Distribution as of the day and year set forth 
below in New York, New York. 

Date: August 8, 1985 
      As Amended on October 21, 1986, 
      January 4, 1993, April 28, 1993, 
      December 19, 1995 and July 28, 1997 

Attest:                                DEAN WITTER CONVERTIBLE 
                                       SECURITIES TRUST 


 ....................................   By:..................................... 


Attest:                                DEAN WITTER DISTRIBUTORS INC. 



 ....................................   By:..................................... 


Attest:                                DEAN WITTER REYNOLDS INC. 



 ....................................   By:..................................... 


                                4








<TABLE> <S> <C>

<PAGE>
<ARTICLE> 6
       
<S>                             <C>
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          SEP-30-1997
<PERIOD-END>                               MAR-31-1997
<INVESTMENTS-AT-COST>                      257,719,011
<INVESTMENTS-AT-VALUE>                     257,141,175
<RECEIVABLES>                                9,950,061
<ASSETS-OTHER>                                  65,821
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                             267,157,057
<PAYABLE-FOR-SECURITIES>                    10,687,115
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                      838,584
<TOTAL-LIABILITIES>                         11,525,699
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                   599,139,750
<SHARES-COMMON-STOCK>                       19,719,736
<SHARES-COMMON-PRIOR>                       18,422,346
<ACCUMULATED-NII-CURRENT>                    4,628,090
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                  (347,558,646)
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                     (577,836)
<NET-ASSETS>                               255,631,358
<DIVIDEND-INCOME>                            1,800,030
<INTEREST-INCOME>                            5,681,253
<OTHER-INCOME>                                       0
<EXPENSES-NET>                               2,255,764
<NET-INVESTMENT-INCOME>                      5,225,519
<REALIZED-GAINS-CURRENT>                     8,482,125
<APPREC-INCREASE-CURRENT>                  (3,886,439)
<NET-CHANGE-FROM-OPS>                        9,821,205
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                  (5,512,213)
<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                      4,474,343
<NUMBER-OF-SHARES-REDEEMED>                (3,522,838)
<SHARES-REINVESTED>                            345,885
<NET-CHANGE-IN-ASSETS>                      21,297,152
<ACCUMULATED-NII-PRIOR>                      4,914,784
<ACCUMULATED-GAINS-PRIOR>                (356,040,771)
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                          734,639
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                              2,255,764
<AVERAGE-NET-ASSETS>                       245,552,456
<PER-SHARE-NAV-BEGIN>                            12.72
<PER-SHARE-NII>                                   0.26
<PER-SHARE-GAIN-APPREC>                           0.27
<PER-SHARE-DIVIDEND>                            (0.29)
<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                              12.96
<EXPENSE-RATIO>                                   1.84
<AVG-DEBT-OUTSTANDING>                               0
<AVG-DEBT-PER-SHARE>                                 0
        

</TABLE>

<PAGE>
                               DEAN WITTER FUNDS
                              MULTIPLE CLASS PLAN
                             PURSUANT TO RULE 18f-3
 
INTRODUCTION
 
    This plan (the "Plan") is adopted pursuant to Rule 18f-3(d) of the
Investment Company Act of 1940, as amended (the "1940 Act"), and will be
effective as of July 28, 1997. The Plan relates to shares of the open-end
investment companies to which Dean Witter InterCapital Inc. acts as investment
manager, that are listed on Schedule A, as may be amended from time to time
(each, a "Fund" and collectively, the "Funds"). The Funds are distributed
pursuant to a system (the "Multiple Class System") in which each class of shares
(each, a "Class" and collectively, the "Classes") of a Fund represents a pro
rata interest in the same portfolio of investments of the Fund and differs only
to the extent outlined below.
 
I.  DISTRIBUTION ARRANGEMENTS
 
    One or more Classes of shares of the Funds are offered for purchase by
investors with the sales load structures described below. In addition, pursuant
to Rule 12b-1 under the 1940 Act, the Funds have each adopted a Plan of
Distribution (the "12b-1 Plan") under which shares of certain Classes are
subject to the service and/or distribution fees ("12b-1 fees") described below.
 
    1.  CLASS A SHARES
 
    Class A shares are offered with a front-end sales load ("FESL"). The
schedule of sales charges applicable to a Fund and the circumstances under which
the sales charges are subject to reduction are set forth in each Fund's current
prospectus. As stated in each Fund's current prospectus, Class A shares may be
purchased at net asset value (without a FESL): (i) in the case of certain large
purchases of such shares; and (ii) by certain limited categories of investors,
in each case, under the circumstances and conditions set forth in each Fund's
current prospectus. Class A shares purchased at net asset value may be subject
to a contingent deferred sales charge ("CDSC") on redemptions made within one
year of purchase. Further information relating to the CDSC, including the manner
in which it is calculated, is set forth in paragraph 6 below. Class A shares are
also subject to payments under each Fund's 12b-1 Plan to reimburse Dean Witter
Distributors Inc., Dean Witter Reynolds Inc. ("DWR"), its affiliates and other
broker-dealers for distribution expenses incurred by them specifically on behalf
of the Class, assessed at an annual rate of up to 0.25% of average daily net
assets. The entire amount of the 12b-1 fee represents a service fee within the
meaning of National Association of Securities Dealers, Inc. ("NASD") guidelines.
 
    2.  CLASS B SHARES
 
    Class B shares are offered without a FESL, but will in most cases be subject
to a six-year declining CDSC which is calculated in the manner set forth in
paragraph 6 below. Class B shares purchased by certain qualified
employer-sponsored benefit plans are subject to a three-year declining CDSC
which is calculated in the manner set forth in paragraph 6 below. The schedule
of CDSC charges applicable to each Fund is set forth in each Fund's current
prospectus. With the exception of certain of the Funds which have a different
formula described below (Dean Witter American Value Fund, Dean Witter Natural
Resource Development Securities Inc., Dean Witter Strategist Fund and Dean
Witter Dividend Growth Securities Inc.)(1), Class B
 
- ------------
 
(1)The payments under the 12b-1 Plan for each of Dean Witter American Value
Fund, Dean Witter Natural Resource Development Securities Inc. and Dean Witter
Dividend Growth Securities Inc. are assessed at the annual rate of 1.0% of the
lesser of: (a) the average daily aggregate gross sales of the Fund's Class B
shares since the inception of the Fund's Plan (not including reinvestment of
dividends or capital gains distributions), less the average daily aggregate net
asset value of the Fund's Class B shares redeemed since the Plan's inception
upon which a contingent deferred sales charge has been imposed or waived, or (b)
the average daily net assets of Class B attributable to shares issued, net of
related shares redeemed, since inception of the Plan. The payments under the
12b-1 Plan for the Dean Witter Strategist Fund are assessed at the annual rate
of: (i) 1% of the lesser of (a) the average daily aggregate gross sales of the
Fund's Class B shares since the effectiveness of the first amendment of the Plan
on November 8, 1989 (not including reinvestment of dividends or capital gains
distributions), less the average daily aggregate net asset value of the Fund's
Class B shares redeemed since the effectiveness of the first amended Plan, upon
which a contingent deferred sales charge has been imposed or waived, or (b) the
average daily net assets of Class B attributable to shares issued, net of
related shares redeemed, since the effectiveness of the first amended Plan; plus
(ii) 0.25% of the average daily net assets of Class B attributable to shares
issued, net of related shares redeemed, prior to effectiveness of the first
amended Plan.
 
                                       1
<PAGE>
shares are also subject to a fee under each Fund's respective 12b-1 Plan,
assessed at the annual rate of up to 1.0% of either: (a) the lesser of (i) the
average daily aggregate gross sales of the Fund's Class B shares since the
inception of the Fund (not including reinvestment of dividends or capital gains
distributions), less the average daily aggregate net asset value of the Fund's
Class B shares redeemed since the Fund's inception upon which a CDSC has been
imposed or waived, or (ii) the average daily net assets of Class B; or (b) the
average daily net assets of Class B. A portion of the 12b-1 fee equal to up to
0.25% of the Fund's average daily net assets is characterized as a service fee
within the meaning of the NASD guidelines and the remaining portion of the 12b-1
fee, if any, is characterized as an asset-based sales charge. Also, Class B
shares have a conversion feature ("Conversion Feature") under which such shares
convert to Class A shares after a certain holding period. Details of the
Conversion Feature are set forth in Section IV below.
 
    3.  CLASS C SHARES
 
    Class C shares are offered without imposition of a FESL, but will in most
cases be subject to a CDSC of 1.0% on redemptions made within one year after
purchase. Further information relating to the CDSC is set forth in paragraph 6
below. In addition, Class C shares, under each Fund's 12b-1 Plan, are subject to
12b-1 payments to reimburse Dean Witter Distributors Inc., DWR, its affiliates
and other broker-dealers for distribution expenses incurred by them specifically
on behalf of the Class, assessed at the annual rate of up to 1.0% of the average
daily net assets of the Class. A portion of the 12b-1 fee equal to up to 0.25%
of the Fund's average daily net assets is characterized as a service fee within
the meaning of NASD guidelines. Unlike Class B shares, Class C shares do not
have the Conversion Feature.
 
    4.  CLASS D SHARES
 
    Class D shares are offered without imposition of a FESL, CDSC or a 12b-1 fee
for purchases of Fund shares by (i) investors meeting an initial minimum
investment requirement and (ii) certain other limited categories of investors,
in each case, as may be approved by the Boards of Directors/Trustees of the
Funds and as disclosed in each Fund's current prospectus.
 
    5.  ADDITIONAL CLASSES OF SHARES
 
    The Boards of Directors/Trustees of the Funds have the authority to create
additional Classes, or change existing Classes, from time to time, in accordance
with Rule 18f-3 under the 1940 Act.
 
    6.  CALCULATION OF THE CDSC
 
    Any applicable CDSC is calculated based upon the lesser of net asset value
of the shares at the time of purchase or at the time of redemption. The CDSC
does not apply to amounts representing an increase in share value due to capital
appreciation and shares acquired through the reinvestment of dividends or
capital gains distributions. The CDSC schedule applicable to a Fund and the
circumstances in which the CDSC is subject to waiver are set forth in each
Fund's prospectus.
 
II.  EXPENSE ALLOCATIONS
 
    Expenses incurred by a Fund are allocated among the various Classes of
shares pro rata based on the net assets of the Fund attributable to each Class,
except that 12b-1 fees relating to a particular Class are allocated directly to
that Class. In addition, other expenses associated with a particular Class
(except advisory or custodial fees), may be allocated directly to that Class,
provided that such expenses are reasonably identified as specifically
attributable to that Class and the direct allocation to that Class is approved
by the Fund's Board of Directors/Trustees.
 
III.  CLASS DESIGNATION
 
    All shares of the Funds held prior to July 28, 1997 (other than the shares
held by certain employee benefit plans established by DWR and its affiliate, SPS
Transaction Services, Inc., shares of Funds offered with a FESL, and shares of
Dean Witter Balanced Growth Fund and Dean Witter Balanced Income Fund) have been
designated Class B shares. Shares held prior to July 28, 1997 by such employee
benefit plans have been designated Class D shares. Shares held prior to July 28,
1997 of Funds offered with a FESL have been designated Class D shares. In
addition, shares of Dean Witter American Value Fund purchased prior to April 30,
1984, shares of Dean Witter Strategist Fund purchased prior to November 8, 1989
and shares of Dean Witter Natural Resource Development Securities Inc. and Dean
Witter Dividend Growth Securities Inc. purchased prior to July 2, 1984 (with
respect to such shares of each Fund, including such proportion of shares
acquired through reinvestment of dividends and capital gains distributions as
the total number of shares acquired prior to each of the preceding dates in this
sentence bears to the total number of shares purchased and owned by the
shareholder of that Fund) have been designated Class D shares. Shares of Dean
Witter Balanced Growth Fund and Dean Witter Balanced Income Fund held prior to
July 28, 1997 have
 
                                       2
<PAGE>
been designated Class C shares except that shares of Dean Witter Balanced Growth
Fund and Dean Witter Balanced Income Fund held prior to July 28, 1997 that were
acquired in exchange for shares of an investment company offered with a CDSC
have been designated Class B shares and those that were acquired in exchange for
shares of an investment company offered with a FESL have been designated Class A
shares.
 
IV.  THE CONVERSION FEATURE
 
    Class B shares held before May 1, 1997 will convert to Class A shares in
May, 2007, except that Class B shares which are purchased before July 28, 1997
by trusts for which Dean Witter Trust Company ("DWTC") or Dean Witter Trust FSB
("DWTFSB") provides discretionary trustee services will convert to Class A
shares on or about August 29, 1997 (the CDSC will not be applicable to such
shares upon the conversion). In all other instances, Class B shares of each Fund
will automatically convert to Class A shares, based on the relative net asset
values of the shares of the two Classes on the conversion date, which will be
approximately ten (10) years after the date of the original purchase.
Conversions will be effected once a month. The 10 year period will be calculated
from the last day of the month in which the shares were purchased or, in the
case of Class B shares acquired through an exchange or a series of exchanges,
from the last day of the month in which the original Class B shares were
purchased, provided that shares originally purchased before May 1, 1997 will
convert to Class A shares in May, 2007. Except as set forth below, the
conversion of shares purchased on or after May 1, 1997 will take place in the
month following the tenth anniversary of the purchase. There will also be
converted at that time such proportion of Class B shares acquired through
automatic reinvestment of dividends owned by the shareholder as the total number
of his or her Class B shares converting at the time bears to the total number of
outstanding Class B shares purchased and owned by the shareholder. In the case
of Class B shares held by a 401(k) plan or other employer-sponsored plan
qualified under Section 401(a) of the Internal Revenue Code (the "Code") and for
which DWTC or DWTFSB serves as Trustee or the 401(k) Support Services Group of
DWR serves as recordkeeper, all Class B shares will convert to Class A shares on
the conversion date of the first shares of a Fund purchased by that plan. In the
case of Class B shares previously exchanged for shares of an "Exchange Fund" (as
such term is defined in the prospectus of each Fund), the period of time the
shares were held in the Exchange Fund (calculated from the last day of the month
in which the Exchange Fund shares were acquired) is excluded from the holding
period for conversion. If those shares are subsequently re-exchanged for Class B
shares of a Fund, the holding period resumes on the last day of the month in
which Class B shares are reacquired.
 
    Effectiveness of the Conversion Feature is subject to the continuing
availability of a ruling of the Internal Revenue Service or an opinion of
counsel to the effect that (i) the conversion of shares does not constitute a
taxable event under the Code; (ii) Class A shares received on conversion will
have a basis equal to the shareholder's basis in the converted Class B shares
immediately prior to the conversion; and (iii) Class A shares received on
conversion will have a holding period that includes the holding period of the
converted Class B shares. The Conversion Feature may be suspended if the Ruling
or opinion is no longer available. In such event, Class B shares would continue
to be subject to Class B fees under the applicable Fund's 12b-1 Plan.
 
V.  EXCHANGE PRIVILEGES
 
    Shares of each Class may be exchanged for shares of the same Class of the
other Funds and for shares of certain other investment companies without the
imposition of an exchange fee as described in the prospectuses and statements of
additional information of the Funds. The exchange privilege of each Fund may be
terminated or revised at any time by the Fund upon such notice as may be
required by applicable regulatory agencies as described in each Fund's
prospectus.
 
VI.  VOTING
 
    Each Class shall have exclusive voting rights on any matter that relates
solely to its 12b-1 Plan, except that Class B shareholders will have the right
to vote on any proposed material increase in Class A's expenses, including
payments under the Class A 12b-1 Plan, if such proposal is submitted separately
to Class A shareholders. If the amount of expenses, including payments under the
Class A 12b-1 Plan, is increased materially without the approval of Class B
shareholders, the Fund will establish a new Class A for Class B shareholders
whose shares automatically convert on the same terms as applied to Class A
before the increase. In addition, each Class shall have separate voting rights
on any matter submitted to shareholders in which the interests of one Class
differ from the interests of any other Class.
 
                                       3
<PAGE>
                               DEAN WITTER FUNDS
                   MULTIPLE CLASS PLAN PURSUANT TO RULE 18f-3
                                   SCHEDULE A
                                AT JULY 28, 1997
 
           
               
1)         Dean Witter American Value Fund
2)         Dean Witter Balanced Growth Fund
3)         Dean Witter Balanced Income Fund
4)         Dean Witter California Tax-Free Income Fund
5)         Dean Witter Capital Appreciation Fund
6)         Dean Witter Capital Growth Securities
7)         Dean Witter Convertible Securities Trust
8)         Dean Witter Developing Growth Securities Trust
9)         Dean Witter Diversified Income Trust
10)        Dean Witter Dividend Growth Securities Inc.
11)        Dean Witter European Growth Fund Inc.
12)        Dean Witter Federal Securities Trust
13)        Dean Witter Financial Services Trust
14)        Dean Witter Global Asset Allocation Fund
15)        Dean Witter Global Dividend Growth Securities
16)        Dean Witter Global Utilities Fund
17)        Dean Witter Health Sciences Trust
18)        Dean Witter High Yield Securities Inc.
19)        Dean Witter Income Builder Fund
20)        Dean Witter Information Fund
21)        Dean Witter Intermediate Income Securities
22)        Dean Witter International SmallCap Fund
23)        Dean Witter Japan Fund
24)        Dean Witter Managers' Select Fund
25)        Dean Witter Market Leader Trust
26)        Dean Witter Mid-Cap Growth Fund
27)        Dean Witter Natural Resource Development Securities Inc.
28)        Dean Witter New York Tax-Free Income Fund
29)        Dean Witter Pacific Growth Fund Inc.
30)        Dean Witter Precious Metals and Minerals Trust
31)        Dean Witter Special Value Fund
32)        Dean Witter Strategist Fund
33)        Dean Witter Tax-Exempt Securities Trust
34)        Dean Witter U.S. Government Securities Trust
35)        Dean Witter Utilities Fund
36)        Dean Witter Value-Added Market Series/Equity Portfolio
37)        Dean Witter World Wide Income Trust
38)        Dean Witter World Wide Investment Trust
            
 
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