<PAGE> 1
PRIME PORTFOLIO
CASH MANAGEMENT CLASS
Supplement dated February 4, 2000
to the Prospectus dated December 17, 1999
At a meeting held on February 3, 2000, the Board of Directors of Short-Term
Investments Co. (the company), on behalf of the Prime Portfolio (the fund),
voted to request shareholders to approve the following items that will
affect the fund:
- - A new advisory agreement between the company and A I M Advisors,
Inc. (AIM). The principal changes to the advisory agreement are
(i) the deletion of references to the provision of administrative
services and certain expense limitations that are no longer
applicable, and (ii) the clarification of provisions relating to
delegations of responsibilities and the non-exclusive nature of
AIM's services. The revised advisory agreement does not change
the fees paid by the fund (except that the agreement permits the
fund to pay a fee to AIM in connection with any new securities
lending program implemented in the future);
- - Changing the fund's fundamental investment restrictions. The
proposed revisions to the fund's fundamental investment
restrictions are described in a supplement to the fund's
statement of additional information; and
- - Changing the fund's investment objective so that it is
non-fundamental. If the investment objective of the fund becomes
non-fundamental, it can be changed in the future by the Board of
Directors of the company without further approval by
shareholders.
The Board of Directors of the company has called a meeting of the fund's
shareholders to be held on or about May 3, 2000 to vote on these and other
proposals. Only shareholders of record as of February 18, 2000 will be
entitled to vote at the meeting. Proposals that are approved are expected
to become effective on or about May 25, 2000.
<PAGE> 2
PRIME PORTFOLIO
INSTITUTIONAL CLASS
Supplement dated February 4, 2000
to the Prospectus dated December 17, 1999
At a meeting held on February 3, 2000, the Board of Directors of Short-Term
Investments Co. (the company), on behalf of the Prime Portfolio (the fund),
voted to request shareholders to approve the following items that will
affect the fund:
- - A new advisory agreement between the company and A I M Advisors,
Inc. (AIM). The principal changes to the advisory agreement are
(i) the deletion of references to the provision of administrative
services and certain expense limitations that are no longer
applicable, and (ii) the clarification of provisions relating to
delegations of responsibilities and the non-exclusive nature of
AIM's services. The revised advisory agreement does not change
the fees paid by the fund (except that the agreement permits the
fund to pay a fee to AIM in connection with any new securities
lending program implemented in the future);
- - Changing the fund's fundamental investment restrictions. The
proposed revisions to the fund's fundamental investment
restrictions are described in a supplement to the fund's
statement of additional information; and
- - Changing the fund's investment objective so that it is
non-fundamental. If the investment objective of the fund becomes
non-fundamental, it can be changed in the future by the Board of
Directors of the company without further approval by
shareholders.
The Board of Directors of the company has called a meeting of the fund's
shareholders to be held on or about May 3, 2000 to vote on these and other
proposals. Only shareholders of record as of February 18, 2000 will be
entitled to vote at the meeting. Proposals that are approved are expected
to become effective on or about May 25, 2000.
<PAGE> 3
PRIME PORTFOLIO
PERSONAL INVESTMENT CLASS
Supplement dated February 4, 2000
to the Prospectus dated December 17, 1999
At a meeting held on February 3, 2000, the Board of Directors of Short-Term
Investments Co. (the company), on behalf of the Prime Portfolio (the fund),
voted to request shareholders to approve the following items that will
affect the fund:
- - A new advisory agreement between the company and A I M Advisors,
Inc. (AIM). The principal changes to the advisory agreement are
(i) the deletion of references to the provision of administrative
services and certain expense limitations that are no longer
applicable, and (ii) the clarification of provisions relating to
delegations of responsibilities and the non-exclusive nature of
AIM's services. The revised advisory agreement does not change
the fees paid by the fund (except that the agreement permits the
fund to pay a fee to AIM in connection with any new securities
lending program implemented in the future);
- - Changing the fund's fundamental investment restrictions. The
proposed revisions to the fund's fundamental investment
restrictions are described in a supplement to the fund's
statement of additional information; and
- - Changing the fund's investment objective so that it is
non-fundamental. If the investment objective of the fund becomes
non-fundamental, it can be changed in the future by the Board of
Directors of the company without further approval by
shareholders.
The Board of Directors of the company has called a meeting of the fund's
shareholders to be held on or about May 3, 2000 to vote on these and other
proposals. Only shareholders of record as of February 18, 2000 will be
entitled to vote at the meeting. Proposals that are approved are expected
to become effective on or about May 25, 2000.
<PAGE> 4
PRIME PORTFOLIO
PRIVATE INVESTMENT CLASS
Supplement dated February 4, 2000
to the Prospectus dated December 17, 1999
At a meeting held on February 3, 2000, the Board of Directors of Short-Term
Investments Co. (the company), on behalf of the Prime Portfolio (the fund),
voted to request shareholders to approve the following items that will
affect the fund:
- - A new advisory agreement between the company and A I M Advisors,
Inc. (AIM). The principal changes to the advisory agreement are
(i) the deletion of references to the provision of administrative
services and certain expense limitations that are no longer
applicable, and (ii) the clarification of provisions relating to
delegations of responsibilities and the non-exclusive nature of
AIM's services. The revised advisory agreement does not change
the fees paid by the fund (except that the agreement permits the
fund to pay a fee to AIM in connection with any new securities
lending program implemented in the future);
- - Changing the fund's fundamental investment restrictions. The
proposed revisions to the fund's fundamental investment
restrictions are described in a supplement to the fund's
statement of additional information; and
- - Changing the fund's investment objective so that it is
non-fundamental. If the investment objective of the fund becomes
non-fundamental, it can be changed in the future by the Board of
Directors of the company without further approval by
shareholders.
The Board of Directors of the company has called a meeting of the fund's
shareholders to be held on or about May 3, 2000 to vote on these and other
proposals. Only shareholders of record as of February 18, 2000 will be
entitled to vote at the meeting. Proposals that are approved are expected
to become effective on or about May 25, 2000.
<PAGE> 5
PRIME PORTFOLIO
RESERVE CLASS
Supplement dated February 4, 2000
to the Prospectus dated December 17, 1999
At a meeting held on February 3, 2000, the Board of Directors of Short-Term
Investments Co. (the company), on behalf of the Prime Portfolio (the fund),
voted to request shareholders to approve the following items that will
affect the fund:
- - A new advisory agreement between the company and A I M Advisors,
Inc. (AIM). The principal changes to the advisory agreement are
(i) the deletion of references to the provision of administrative
services and certain expense limitations that are no longer
applicable, and (ii) the clarification of provisions relating to
delegations of responsibilities and the non-exclusive nature of
AIM's services. The revised advisory agreement does not change
the fees paid by the fund (except that the agreement permits the
fund to pay a fee to AIM in connection with any new securities
lending program implemented in the future);
- - Changing the fund's fundamental investment restrictions. The
proposed revisions to the fund's fundamental investment
restrictions are described in a supplement to the fund's
statement of additional information; and
- - Changing the fund's investment objective so that it is
non-fundamental. If the investment objective of the fund becomes
non-fundamental, it can be changed in the future by the Board of
Directors of the company without further approval by
shareholders.
The Board of Directors of the company has called a meeting of the fund's
shareholders to be held on or about May 3, 2000 to vote on these and other
proposals. Only shareholders of record as of February 18, 2000 will be
entitled to vote at the meeting. Proposals that are approved are expected
to become effective on or about May 25, 2000.
<PAGE> 6
PRIME PORTFOLIO
RESOURCE CLASS
Supplement dated February 4, 2000
to the Prospectus dated December 17, 1999
At a meeting held on February 3, 2000, the Board of Directors of Short-Term
Investments Co. (the company), on behalf of the Prime Portfolio (the fund),
voted to request shareholders to approve the following items that will
affect the fund:
- - A new advisory agreement between the company and A I M Advisors,
Inc. (AIM). The principal changes to the advisory agreement are
(i) the deletion of references to the provision of administrative
services and certain expense limitations that are no longer
applicable, and (ii) the clarification of provisions relating to
delegations of responsibilities and the non-exclusive nature of
AIM's services. The revised advisory agreement does not change
the fees paid by the fund (except that the agreement permits the
fund to pay a fee to AIM in connection with any new securities
lending program implemented in the future);
- - Changing the fund's fundamental investment restrictions. The
proposed revisions to the fund's fundamental investment
restrictions are described in a supplement to the fund's
statement of additional information; and
- - Changing the fund's investment objective so that it is
non-fundamental. If the investment objective of the fund becomes
non-fundamental, it can be changed in the future by the Board of
Directors of the company without further approval by
shareholders.
The Board of Directors of the company has called a meeting of the fund's
shareholders to be held on or about May 3, 2000 to vote on these and other
proposals. Only shareholders of record as of February 18, 2000 will be
entitled to vote at the meeting. Proposals that are approved are expected
to become effective on or about May 25, 2000.
<PAGE> 7
SHORT-TERM INVESTMENTS CO.
PRIME PORTFOLIO
(CASH MANAGEMENT CLASS)
(INSTITUTIONAL CLASS)
(PERSONAL INVESTMENT CLASS)
(PRIVATE INVESTMENT CLASS)
(RESERVE CLASS)
(RESOURCE CLASS)
Supplement dated February 4, 2000
to the Statement of Additional Information dated December 17, 1999
At a meeting held on February 3, 2000, the Board of Directors of Short-Term
Investments Co. (the "Company"), on behalf of the Prime Portfolio (the
"Portfolio"), voted to request shareholder approval to amend the Portfolio's
fundamental investment restrictions. The Board of Directors has called a meeting
of the Portfolio's shareholders to be held on or about May 3, 2000. Only
shareholders of record as of February 18, 2000 are entitled to vote at the
meeting. Proposals that are approved are expected to become effective on or
about May 25, 2000.
If shareholders approve the proposal to amend the Portfolio's fundamental
investment restrictions, the Prime Portfolio will operate under the following
fundamental investment restrictions:
The Portfolio is subject to the following investment restrictions, which may be
changed only by a vote of a majority of the Portfolio's outstanding shares:
(a) the Portfolio is a "diversified company" as defined in the
1940 Act. The Portfolio will not purchase the securities of any issuer
if, as a result, the Portfolio would fail to be a diversified company
within the meaning of the 1940 Act, and the rules and regulations
promulgated thereunder, as such statute, rules and regulations are
amended from time to time or are interpreted from time to time by the
SEC staff (collectively, the 1940 Act laws and interpretations) or
except to the extent that the Portfolio may be permitted to do so by
exemptive order or similar relief (collectively, with the 1940 Act laws
and interpretations, the 1940 Act laws, interpretations and
exemptions). In complying with this restriction, however, the Portfolio
may purchase securities of other investment companies to the extent
permitted by the 1940 Act laws, interpretations and exemptions.
(b) the Portfolio may not borrow money or issue senior
securities, except as permitted by the 1940 Act laws, interpretations
and exemptions.
(c) the Portfolio may not underwrite the securities of other
issuers. This restriction does not prevent the Portfolio from engaging
in transactions involving the acquisition, disposition or resale of its
portfolio securities, regardless of whether the Portfolio may be
considered to be an underwriter under the Securities Act of 1933.
(d) the Portfolio will not make investments that will result
in the concentration (as that term may be defined or interpreted by the
1940 Act laws, interpretations and exemptions) of its investments in
the securities of issuers primarily engaged in the same industry. This
restriction does not limit the Portfolio's investments in (i)
obligations issued or guaranteed by the U.S. Government, its agencies
or instrumentalities, (ii) tax-exempt obligations issued by governments
or political subdivisions of governments, or (iii) bank instruments. In
complying with this restriction, the Portfolio will not consider a
bank-issued guaranty or financial guaranty insurance as a separate
security.
(e) the Portfolio may not purchase real estate or sell real
estate unless acquired as a result of ownership of securities or other
instruments. This restriction does not prevent the Portfolio from
investing
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<PAGE> 8
in issuers that invest, deal, or otherwise engage in transactions in
real estate or interests therein, or investing in securities that are
secured by real estate or interests therein.
(f) the Portfolio may not purchase physical commodities or
sell physical commodities unless acquired as a result of ownership of
securities or other instruments. This restriction does not prevent the
Portfolio from engaging in transactions involving futures contracts and
options thereon or investing in securities that are secured by physical
commodities.
(g) the Portfolio may not make personal loans or loans of its
assets to persons who control or are under common control with the
Portfolio, except to the extent permitted by 1940 Act laws,
interpretations and exemptions. This restriction does not prevent the
Portfolio from, among other things, purchasing debt obligations,
entering into repurchase agreements, loaning its assets to
broker-dealers or institutional investors, or investing in loans,
including assignments and participation interests.
(h) the Portfolio may, notwithstanding any other fundamental
investment policy or limitation, invest all of its assets in the
securities of a single open-end management investment company with
substantially the same fundamental investment objectives, policies and
restrictions as the Portfolio.
The investment restrictions set forth above provide the Portfolio with the
ability to operate under new interpretations of the 1940 Act or pursuant to
exemptive relief from the SEC without receiving prior shareholder approval of
the change. Even though the Portfolio has this flexibility, the Board of
Directors of the Company has adopted internal guidelines for the Portfolio
relating to certain of these restrictions which the advisor must follow in
managing the Portfolio. Any changes to these guidelines, which are set forth
below, require the approval of the Board of Directors.
1. In complying with the fundamental restriction regarding issuer
diversification, the Portfolio will not, with respect to 100% of
its total assets, purchase securities of any issuer (other than
securities issued or guaranteed by the U.S. Government or any of
its agencies or instrumentalities), if, as a result, (i) more
than 5% of the Portfolio's total assets would be invested in the
securities of that issuer, except as permitted by Rule 2a-7 under
the 1940 Act, or (ii) the Portfolio would hold more than 10% of
the outstanding voting securities of that issuer. The Portfolio
may (i) purchase securities of other investment companies as
permitted by Section 12(d)(1) of the 1940 Act and (ii) invest its
assets in securities of other money market funds and lend money
to other investment companies and their series portfolios that
have AIM as an investment advisor, subject to the terms and
conditions of any exemptive orders issued by the SEC.
2. In complying with the fundamental restriction regarding borrowing
money and issuing senior securities, the Portfolio may borrow
money in an amount not exceeding 33 1/3% of its total assets
(including the amount borrowed) less liabilities (other than
borrowings). The Portfolio may borrow from banks, broker/dealers
or other investment companies or their series portfolios that
have AIM or an affiliate of AIM as an investment advisor (an AIM
fund). The Portfolio may not borrow for leveraging, but may
borrow for temporary or emergency purposes, in anticipation of or
in response to adverse market conditions, or for cash management
purposes. The Portfolio may not purchase additional securities
when any borrowings from banks exceed 5% of the Portfolio's total
assets.
3. In complying with the fundamental restriction regarding industry
concentration, the Portfolio may invest up to 25% of its total
assets in the securities of issuers whose principal business
activities are in the same industry.
4. In complying with the fundamental restriction with regard to
making loans, the Portfolio may lend up to 33 1/3% of its total
assets and may lend money to another AIM fund, on such terms and
conditions as the SEC may require in an exemptive order.
5. Notwithstanding the fundamental restriction on investing all of
the Portfolio's assets in an open-end fund, the Portfolio may not
invest all of its assets in the securities of a single open-end
management investment company with the same fundamental
investment objectives, policies and limitations as the Portfolio.
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<PAGE> 9
If a percentage restriction is adhered to at the time of investment, a later
change in percentage resulting from changes in values of assets will not be
considered a violation of the restriction.
Effective immediately, the following replaces in its entirety the paragraph with
the heading "INVESTMENT PROGRAM AND RESTRICTIONS - INVESTMENT IN OTHER
INVESTMENT COMPANIES" on page A-23 of the Statement of Additional Information:
"INVESTMENT IN OTHER INVESTMENT COMPANIES. The Portfolio may
invest in other investment companies to the extent permitted by the
1940 Act, and rules and regulations thereunder, and if applicable,
exemptive orders granted by the SEC. The following restrictions apply
to investments in other investment companies other than Affiliated
Money Market Funds (defined below): (i) the Portfolio may not purchase
more than 3% of the total outstanding voting stock of another
investment company; (ii) the Portfolio may not invest more than 5% of
its total assets in securities issued by another investment company;
and (iii) the Portfolio may not invest more than 10% of its total
assets in securities issued by other investment companies other than
Affiliated Money Market Funds. With respect to the Portfolio's
purchase of shares of another investment company, including Affiliated
Money Market Funds, the Portfolio will indirectly bear its
proportionate share of the advisory fees and other operating expenses
of such investment company. The Portfolio has obtained an exemptive
order from the SEC allowing it to invest in money market funds that
have AIM or an affiliate of AIM as an investment adviser (the
"Affiliated Money Market Funds"), provided that investments in
Affiliated Money Market Funds do not exceed 25% of the total assets of
the Portfolio. With respect to the Portfolio's purchase of shares of
the Affiliated Money Market Funds, the Portfolio will indirectly pay
the advisory fees and other operating expenses of the Affiliated Money
Market Funds."
3
