<PAGE>
[AIM LOGO APPEARS HERE] Dear Shareholder:
- --Registered Trademark--
[PHOTO of As the end of the six-month reporting period
Charles T. Bauer arrived, the U.S. economy continued to move
Chairman of the ahead at a lively pace. The Federal Reserve
LETTER Board of The Fund Board (the Fed) increased the key federal
TO OUR APPEARS HERE] funds rate a total of 75 basis points during
SHAREHOLDERS 1999. At the beginning of this reporting
period, the Fed's primary focus was to
stabilize the markets in anticipation of a potential Y2K-related
liquidity crisis. Y2K thankfully turned out to be a non-event. As
2000 began, the robust domestic economy (coupled with inflationary
tendencies in certain commodity prices) compelled the Fed to
increase the federal funds rate 25 basis points on March 21 to
6.00%. The Fed will most likely continue to increase short-term
rates to contain the equity markets' high growth performance; there
is a strong consensus among financial markets that the Fed will
increase rates by 25 basis points at the May 16 meeting. If the rate
hikes do halt or slow the equity markets' activity, the money market
sector anticipates more incoming cash as the year progresses.
YOUR INVESTMENT PORTFOLIO
Through a combination of short-term cash-management vehicles and
the selective use of a longer maturity schedule for higher yields,
the portfolio continued to provide attractive returns. Weighted
average maturity (WAM) was held at a moderate length for much of the
period due to concerns about an increase in short-term interest
rates. The WAM remained in the 34- to 58-day range; the WAM closed
the period at 38 days. This strategy produced competitive yields. As
of February 29, 2000, the average monthly yield of the Private
Investment Class was 4.91%; the seven-day yield was 4.95%. Net
assets of the Private Investment Class stood at $50.7 million as of
the close of the reporting period.
The portfolio continues to hold the highest credit-quality ratings
given by three widely known credit-rating agencies: AAAm from
Standard & Poor's, Aaa from Moody's and AAA from Fitch IBCA. These
historical ratings are based on an analysis of the portfolio's
credit quality, composition, management and weekly portfolio
reviews. AIM is the largest multi-fund complex to have all its
institutional money market portfolios given the highest rating by
three nationally recognized ratings agencies, according to IBC
Financial Data, Inc.
The Treasury TaxAdvantage Portfolio seeks to maximize current
income to the extent consistent with preservation of capital and
maintenance of liquidity. It purchases only direct obligations of
the U.S. Treasury which provide shareholders with dividends exempt
from state and local income taxation in certain jurisdictions.
Government securities, such as U.S. Treasury bills and notes, offer
a high degree of safety and guarantee the timely payment of
principal and interest if held to maturity. An investment in a money
market fund is not insured or guaranteed by the Federal Deposit
Insurance Corporation or any other government agency. Although a
money market fund seeks to preserve the value of your investment at
$1.00 per share, it is possible to lose money investing in the fund.
(continued)
<PAGE>
OUTLOOK FOR THE FUTURE
Gross domestic product growth for the fourth quarter of 1999 was
at an annualized rate of 7.3%, and for the year 4.2%. There is no
evidence of a slowdown; there is no inventory drop-off and
consumer spending continues to increase. February's rate increase
has had a minimal effect on the U.S. economy, which continues
full steam ahead. The Fed will probably continue to raise
interest rates until a substantial correction occurs within the
equity markets. In February, the current period of economic
expansion became the longest in U.S. history. Many analysts
expect this growth to continue through at least the first half of
2000. It seems that the same story that dogged markets in 1999 is
so far continuing, with persistent upward pressure on interest
rates.
We are pleased to send you this report on your investment. AIM
is committed to the primary goals of safety, liquidity and yield
in institutional fund management. We are also dedicated to
customer service, and we are ready to respond to your comments
about this report. If you have any questions, please contact one
of our representatives at 800-659-1005 if we may help.
Respectfully submitted,
/s/ CHARLES T. BAUER
Charles T. Bauer
Chairman
2
<PAGE>
SCHEDULE OF INVESTMENTS
February 29, 2000
(Unaudited)
<TABLE>
<CAPTION>
PAR
MATURITY (000) VALUE
<S> <C> <C> <C>
U.S. TREASURY BILLS(a) - 96.11%
5.14% 03/02/00 $ 5,000 $ 4,999,286
- ------------------------------------------------------------------------------
4.93% 03/16/00 20,000 19,958,917
- ------------------------------------------------------------------------------
5.00% 03/30/00 20,000 19,919,444
- ------------------------------------------------------------------------------
5.22% 04/06/00 10,000 9,947,800
- ------------------------------------------------------------------------------
5.26% 04/13/00 5,000 4,968,586
- ------------------------------------------------------------------------------
5.29% 04/20/00 10,000 9,926,528
- ------------------------------------------------------------------------------
5.33% 04/20/00 5,000 4,962,986
- ------------------------------------------------------------------------------
5.36% 04/27/00 10,000 9,915,133
- ------------------------------------------------------------------------------
5.71% 04/27/00 10,000 9,909,671
- ------------------------------------------------------------------------------
5.58% 05/11/00 6,000 5,933,970
- ------------------------------------------------------------------------------
Total U.S. Treasury Bills (Cost $100,442,321) 100,442,321
- ------------------------------------------------------------------------------
TOTAL INVESTMENTS -- 96.11% (Cost $100,442,321) 100,442,321
- ------------------------------------------------------------------------------
OTHER ASSETS LESS LIABILITIES -- 3.89% 4,070,373
- ------------------------------------------------------------------------------
NET ASSETS -- 100.00% $104,512,694
- ------------------------------------------------------------------------------
</TABLE>
NOTES TO SCHEDULE OF INVESTMENTS:
(a) U.S. Treasury bills are traded on a discount basis. In such cases the
interest rate shown represents the rate of discount paid or received at the
time of purchase by the Portfolio.
See Notes to Financial Statements.
3
<PAGE>
STATEMENT OF ASSETS AND LIABILITIES
February 29, 2000
(Unaudited)
<TABLE>
<S> <C>
ASSETS:
Investments, at value (amortized cost) $100,442,321
- ----------------------------------------------------------------------
Cash 4,495,750
- ----------------------------------------------------------------------
Investment for deferred compensation plan 35,588
- ----------------------------------------------------------------------
Other assets 32,037
- ----------------------------------------------------------------------
Total assets 105,005,696
- ----------------------------------------------------------------------
LIABILITIES:
Payables for:
Dividends 415,215
- ----------------------------------------------------------------------
Deferred compensation 35,588
- ----------------------------------------------------------------------
Accrued administrative services fees 3,962
- ----------------------------------------------------------------------
Accrued distribution fees 8,920
- ----------------------------------------------------------------------
Accrued transfer agent fees 8,017
- ----------------------------------------------------------------------
Accrued trustees' fees 1,210
- ----------------------------------------------------------------------
Accrued operating expenses 20,090
- ----------------------------------------------------------------------
Total liabilities 493,002
- ----------------------------------------------------------------------
NET ASSETS $104,512,694
======================================================================
NET ASSETS:
Institutional Class $ 53,788,531
======================================================================
Private Investment Class $ 50,724,161
======================================================================
Cash Management Class $ 1
======================================================================
Resource Class $ 1
======================================================================
SHARES OF BENEFICIAL INTEREST, $.01 PAR VALUE PER SHARE:
Institutional Class 53,791,599
======================================================================
Private Investment Class 50,738,890
======================================================================
Cash Management Class 1
======================================================================
Resource Class 1
======================================================================
NET ASSET VALUE PER SHARE:
Net asset value, offering and redemption price per share $ 1.00
======================================================================
</TABLE>
See Notes to Financial Statements.
4
<PAGE>
STATEMENT OF OPERATIONS
For the six months ended February 29, 2000
(Unaudited)
<TABLE>
<S> <C>
INVESTMENT INCOME:
Interest income $3,051,199
- ----------------------------------------------------------------
EXPENSES:
Advisory fees 123,553
- ----------------------------------------------------------------
Custodian fees 5,323
- ----------------------------------------------------------------
Administrative services fees 24,863
- ----------------------------------------------------------------
Trustees' fees 3,927
- ----------------------------------------------------------------
Transfer agent fees 17,658
- ----------------------------------------------------------------
Distribution fees (see Note 2) 116,935
- ----------------------------------------------------------------
Filing fees 20,592
- ----------------------------------------------------------------
Other 28,606
- ----------------------------------------------------------------
Total expenses 341,457
- ----------------------------------------------------------------
Less: Fee waivers and reimbursements (212,040)
- ----------------------------------------------------------------
Net expenses 129,417
- ----------------------------------------------------------------
Net investment income 2,921,782
- ----------------------------------------------------------------
Net realized gain (loss) on sales of investments (49,828)
- ----------------------------------------------------------------
Net increase in net assets resulting from operations $2,871,954
================================================================
</TABLE>
See Notes to Financial Statements.
5
<PAGE>
STATEMENT OF CHANGES IN NET ASSETS
For the six months ended February 29, 2000 and year ended August 31, 1999
(Unaudited)
<TABLE>
<CAPTION>
FEBRUARY 29, AUGUST 31,
2000 1999
------------ ------------
<S> <C> <C>
OPERATIONS:
Net investment income $ 2,921,782 $ 6,402,815
- -----------------------------------------------------------------------------
Net realized gain (loss) on sales of investments (49,828) (10,840)
- -----------------------------------------------------------------------------
Net increase in net assets resulting from
operations 2,871,954 6,391,975
- -----------------------------------------------------------------------------
Distributions to shareholders from net investment income:
Institutional Class (1,830,000) (4,317,947)
- -----------------------------------------------------------------------------
Private Class (1,068,890) (2,084,868)
- -----------------------------------------------------------------------------
Cash Management Class (5,288) --
- -----------------------------------------------------------------------------
Resource Class (17,604) --
- -----------------------------------------------------------------------------
Share transactions-net (see Note 4) (29,330,768) (10,323,072)
- -----------------------------------------------------------------------------
Net increase (decrease) in net assets (29,380,596) (10,333,912)
- -----------------------------------------------------------------------------
NET ASSETS:
Beginning of period 133,893,290 144,227,202
- -----------------------------------------------------------------------------
End of period $104,512,694 $133,893,290
=============================================================================
NET ASSETS CONSIST OF:
Shares of beneficial interest $104,530,491 $133,861,259
- -----------------------------------------------------------------------------
Undistributed net realized gain (loss) on sales
of investments (17,797) 32,031
- -----------------------------------------------------------------------------
$104,512,694 $133,893,290
=============================================================================
</TABLE>
See Notes to Financial Statements.
6
<PAGE>
NOTES TO FINANCIAL STATEMENTS
February 29, 2000
(Unaudited)
NOTE 1-SIGNIFICANT ACCOUNTING POLICIES
Short-Term Investments Trust (the "Fund") is registered under the Investment
Company Act of 1940, as amended, as an open-end series, diversified management
investment company. The Fund is organized as a Delaware business trust
consisting of three different portfolios, each of which offers separate series
of shares: the Treasury TaxAdvantage Portfolio, the Government & Agency
Portfolio and the Treasury Portfolio. Information presented in these financial
statements pertains only to the Treasury TaxAdvantage Portfolio (the
"Portfolio") with the assets, liabilities and operations of each portfolio
accounted for separately. The Portfolio currently offers six different classes
of shares: the Institutional Class, the Private Investment Class, the Personal
Investment Class, the Cash Management Class, the Reserve Class and the Resource
Class. Sales of the Personal Investment Class and the Reserve Class have not
yet commenced. Matters affecting each class are voted on exclusively by the
shareholders of each class. The Portfolio is a money market fund whose
investment objective is the maximization of current income to the extent
consistent with the preservation of capital and the maintenance of liquidity.
The preparation of financial statements in conformity with generally accepted
accounting principles requires management to make estimates and assumptions
that affect the reported amounts of assets and liabilities at the date of these
financial statements and the reported amount of revenues and expenses during
the reporting period. Actual results could differ from those estimates. The
following is a summary of the significant accounting policies followed by the
Portfolio in the preparation of its financial statements.
A. Security Valuations - The Portfolio's securities are valued on the basis of
amortized cost which approximates market value. This method values a
security at its cost on the date of purchase and thereafter assumes a
constant amortization to maturity of any discount or premium.
B. Securities Transactions, Investment Income and Distributions - Securities
transactions are accounted for on a trade date basis. Realized gains or
losses are computed on the basis of specific identification of the
securities sold. Interest income, adjusted for amortization of premiums and
discounts on investments, is accrued daily. Dividends to shareholders are
declared daily and are paid on the first business day of the following
month.
C. Federal Income Taxes - The Portfolio intends to comply with the requirements
of the Internal Revenue Code necessary to qualify as a regulated investment
company and, as such, will not be subject to federal income taxes on
otherwise taxable income (including net realized capital gains) which is
distributed to shareholders. Therefore, no provision for federal income
taxes is recorded in the financial statements.
D. Expenses - Distribution expenses directly attributable to a class of shares
are charged to that class' operations. All other expenses which are
attributable to more than one class are allocated among the classes.
NOTE 2-ADVISORY FEES AND OTHER TRANSACTIONS WITH AFFILIATES
The Fund has entered into a master investment advisory agreement with A I M
Advisors, Inc. ("AIM"). Under the terms of the master investment advisory
agreement, AIM receives a monthly fee with respect to the Portfolio calculated
by applying a monthly rate, based upon the following annual rates, to the
average daily net assets of the Portfolio:
<TABLE>
<CAPTION>
Net Assets RATE
- ------------------------------------------------------------------------------
<S> <C>
First $250 million 0.20%
- ------------------------------------------------------------------------------
Over $250 million to $500 million 0.15%
- ------------------------------------------------------------------------------
Over $500 million 0.10%
- ------------------------------------------------------------------------------
</TABLE>
During the six months ended February 29, 2000, AIM waived advisory fees of
$123,553 and reimbursed fees of $30,284.
The Fund, pursuant to a master administrative services agreement with AIM, has
agreed to pay AIM for certain administrative costs incurred in providing
accounting services to the Fund. During the six months ended February 29, 2000,
AIM was paid $24,863 for such services.
7
<PAGE>
The Fund, pursuant to a transfer agency and service agreement, has agreed to
pay A I M Fund Services, Inc. ("AFS") a fee for providing transfer agent and
shareholder services to the Fund. During the six months ended February 29,
2000, AFS was paid $9,637 for such services.
Under the terms of a master distribution agreement between Fund Management
Company ("FMC") and the Fund, FMC acts as the exclusive distributor of the
Fund's shares. The Fund has adopted a master distribution plan (the "Plan")
pursuant to Rule 12b-1 under the 1940 Act with respect to the Private
Investment Class, the Personal Investment Class, the Cash Management Class, the
Reserve Class, and the Resource Class of the Portfolio. The Plan provides that
the Private Investment Class, the Personal Investment Class, the Cash
Management Class, the Reserve Class, and the Resource Class pay up to a 0.50%,
0.75%, 0.10%, 1.00%, and 0.20%, respectively, maximum annual rate of the
average daily net assets attributable to such class. Of this amount, the Fund
may pay an asset-based sales charge to FMC and the Fund may pay a service fee
of (a) 0.25% of the average daily net assets of each of the Private Investment
Class, the Personal Investment Class, and the Reserve Class, (b) 0.10% of the
average daily net assets of the Cash Management Class and (c) 0.20% of the
average daily net assets of the Resource Class, to selected banks, broker-
dealers and other financial institutions who offer continuing personal
shareholder services to their customers who purchase and own shares of the
Private Investment Class, the Personal Investment Class, the Cash Management
Class, the Reserve Class, or the Resource Class. Any amounts not paid as a
service fee under such Plan would constitute an asset-based sales charge. The
Plan also imposes a cap on the total amount of sales charges, including asset-
based sales charges, that may be paid by the Portfolio with respect to each
class. Currently, FMC has elected to waive a portion of its compensation
payable by the Fund such that the compensation paid pursuant to the Plan with
respect to the Private Investment Class, the Personal Investment Class, the
Cash Management Class, the Reserve Class, and the Resource Class equals 0.25%,
0.50%, 0.08%, 0.80% and 0.16%, respectively, maximum annual rate of the average
daily net assets attributable to such class. During the six months ended
February 29, 2000, the Private Investment Class, the Cash Management Class and
the Resource Class paid $58,027, $91 and $614, respectively, as compensation
under the Plan. FMC waived fees of $58,203 for the same period.
Certain officers and trustees of the Trust are officers of AIM, FMC and AFS.
During the six months ended February 29, 2000, the Fund paid legal fees of
$1,092 for services rendered by Kramer, Levin, Naftalis & Frankel LLP as
counsel to the Board of Trustees. A member of that firm is a trustee of the
Fund.
NOTE 3-TRUSTEES' FEES
Trustees' fees represent remuneration paid to trustees who are not an
"interested person" of AIM. The Fund may invest trustees' fees, if so elected
by a trustee, in mutual fund shares in accordance with a deferred compensation
plan.
NOTE 4-SHARE INFORMATION
Changes in shares outstanding during the six months ended February 29, 2000 and
the year ended August 31, 1999 were as follows:
<TABLE>
<CAPTION>
FEBRUARY 29, 2000 AUGUST 31, 1999
--------------------------- ---------------------------
SHARES AMOUNT SHARES AMOUNT
------------ ------------- ------------ -------------
<S> <C> <C> <C> <C>
Sold:
Institutional Class 424,416,166 $ 424,416,166 606,748,092 $ 606,748,092
- ---------------------------------------------------------------------------------------
Private Investment Class 520,894,207 520,894,207 605,044,466 605,044,466
- ----------------------------------------------------------------------------------------
Cash Management Class* 10,364,472 10,364,472 -- --
- ---------------------------------------------------------------------------------------
Resource Class* 35,063,662 35,063,662 -- --
- ---------------------------------------------------------------------------------------
Issued as reinvestment of dividends:
Institutional Class 139,788 139,788 477,705 477,705
- ---------------------------------------------------------------------------------------
Private Investment Class 568,852 568,852 1,198,839 1,198,839
- ---------------------------------------------------------------------------------------
Cash Management Class* 4,671 4,671 -- --
- ---------------------------------------------------------------------------------------
Resource Class* 8,800 8,800 -- --
- ---------------------------------------------------------------------------------------
Reacquired:
Institutional Class (459,259,946) (459,259,946) (631,780,898) (631,780,898)
- ---------------------------------------------------------------------------------------
Private Investment Class (516,089,837) (516,089,837) (592,011,276) (592,011,276)
- ---------------------------------------------------------------------------------------
Cash Management Class* (10,369,142) (10,369,142) -- --
- ---------------------------------------------------------------------------------------
Resource Class* (35,072,461) (35,072,461) -- --
- ---------------------------------------------------------------------------------------
Net increase (decrease) (29,330,768) $ (29,330,768) (10,323,072) $ (10,323,072)
=======================================================================================
</TABLE>
* The Cash Management Class and the Resource Class commenced sales on December
30, 1999.
8
<PAGE>
NOTE 5-FINANCIAL HIGHLIGHTS
Shown below are the financial highlights for a share of the Private Investment
Class outstanding during the six months ended February 29, 2000 and each of the
years in the four-year period ended August 31, 1999 and the period December 21,
1994 (date sales commenced) through August 31, 1995.
<TABLE>
<CAPTION>
AUGUST 31,
FEBRUARY 29, ------------------------------------------
2000 1999 1998 1997 1996 1995
------------ ------- ------- ------- ------- ------
<S> <C> <C> <C> <C> <C> <C>
Net asset value, beginning of period $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00
- ---------------------------------------------------- ------- ------- ------- ------- ------- ------
Income from investment operations:
Net investment income 0.02 0.04 0.05 0.05 0.05 0.04
- ---------------------------------------------------- ------- ------- ------- ------- ------- ------
Less distributions:
Dividends from net investment income (0.02) (0.04) (0.05) (0.05) (0.05) (0.04)
- ---------------------------------------------------- ------- ------- ------- ------- ------- ------
Net asset value, end of period $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00 $ 1.00
==================================================== ======= ======= ======= ======= ======= ======
Total return(a) 2.32% 4.25% 5.04% 4.87% 4.93% 3.69%
==================================================== ======= ======= ======= ======= ======= ======
Ratios/supplemental data:
Net assets, end of period (000s omitted) $50,724 $45,377 $31,143 $39,312 $49,978 $5,423
- ---------------------------------------------------- ------- ------- ------- ------- ------- ------
Ratio of expenses to average net assets:
Including fee waivers and/or expense
reimbursements 0.36%(b) 0.43% 0.45% 0.45% 0.45% 0.45%(c)
- ---------------------------------------------------- ------ ------ ------ ------ ------ ------
Excluding fee waivers and/or expense
reimbursements 0.86%(b) 0.85% 0.78% 0.74% 0.85% 1.02%(c)
- ---------------------------------------------------- ------ ------ ------ ------ ------ ------
Ratio of net investment income to average net assets 4.59%(b) 4.18% 4.80% 4.75% 4.72% 5.21%(c)
==================================================== ====== ====== ====== ====== ====== ======
</TABLE>
(a) Not annualized for periods less than one year.
(b) Ratios are annualized and based on average net assets of $46,676,621.
(c) Annualized.
9
<PAGE>
<TABLE>
<CAPTION>
TRUSTEES
<S> <C>
Charles T. Bauer Carl Frischling
Bruce L. Crockett Robert H. Graham Short-Term
Owen Daly II Prema Mathai-Davis Investments Trust
Edward K. Dunn, Jr. Lewis F. Pennock (STIT)
Jack M. Fields Louis S. Sklar
OFFICERS
Charles T. Bauer Chairman
Robert H. Graham President Treasury
Gary T. Crum Sr. Vice President TaxAdvantage
Carol F. Relihan Sr. Vice President & Secretary Portfolio
Dana R. Sutton Vice President & Treasurer --------------------------------------------
Melville B. Cox Vice President Private SEMI-
Karen Dunn Kelley Vice President Investment ANNUAL
J. Abbott Sprague Vice President Class REPORT
Mary J. Benson Assistant Vice President & Assistant Treasurer
Sheri Morris Assistant Vice President & Assistant Treasurer
Renee A. Friedli Assistant Secretary
P. Michelle Grace Assistant Secretary FEBRUARY 29, 2000
Nancy L. Martin Assistant Secretary
Ofelia M. Mayo Assistant Secretary
Lisa A. Moss Assistant Secretary
Kathleen J. Pflueger Assistant Secretary
Samuel D. Sirko Assistant Secretary
Stephen I. Winer Assistant Secretary
INVESTMENT ADVISOR
A I M Advisors, Inc.
11 Greenway Plaza, Suite 100
Houston, TX 77046-1173
800-347-1919
DISTRIBUTOR
Fund Management Company
11 Greenway Plaza, Suite 100
Houston, TX 77046-1173
800-659-1005
CUSTODIAN
The Bank of New York
90 Washington Street, 11th Floor
New York, NY 10286
LEGAL COUNSEL TO FUND
Ballard Spahr Andrews & Ingersoll, LLP
1735 Market Street, 51st Floor
Philadelphia, PA 19103-7599
LEGAL COUNSEL TO TRUSTEES
Kramer, Levin, Naftalis & Frankel LLP
919 Third Avenue
New York, NY 10022
TRANSFER AGENT
A I M Fund Services, Inc.
11 Greenway Plaza, Suite 100
Houston, TX 77046-1173
This report may be distributed only to current shareholders or
to persons who have received a current prospectus. Fund Management Company
[LOGO APPEARS HERE]
</TABLE>
TAP-SAR-2
