Rule 497(e)
Registration No. 33-73824
File No. 811-8274
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MASSMUTUAL INSTITUTIONAL FUNDS
Supplement dated February 1, 1999
to the Prospectus dated May 1, 1998, as
previously supplemented December 1, 1998
THE PROSPECTUS IS CHANGED AS FOLLOWS:
1. The second paragraph on page 21 of the Prospectus, under the heading
"FEATURES AND ELIGIBILITY REQUIREMENTS OF EACH CLASS" under the caption "CLASS
S SHARES", is hereby replaced with the following:
CLASS S SHARES
ELIGIBLE PURCHASERS. Class S shares may be purchased by separate
investment accounts of MassMutual. Class S shares also may be purchased
by
* Qualified plans under Section 401(a) of the Internal Revenue Code of
1986, and other retirement plans, which have Plan Assets in excess of
$100 million; and
* Other institutional investors with assets generally in excess of $100
million.
These Investors must have an agreement with the Adviser or an affiliate
of the Adviser to purchase Class S shares.
2. The paragraph on page 21 of the Prospectus entitled "CLASS S SHARES - NO
SALES CHARGES" is hereby replaced with the following:
Class S shares of each Fund are purchased directly from the Trust without
a front-end sales charge. Therefore, 100% of an Investor's money is
invested in the Fund or Funds of its choice. Class S shares do not have
deferred sales charges or any distribution or service fees.
