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DECHERT PRICE & RHOADS
1775 EYE STREET, N.W.
WASHINGTON, D.C. 20006
(202) 261-3300
May 6, 1998
VIA ELECTRONIC TRANSMISSION
Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20005
Re: MainStay Institutional Funds Inc.
File Nos. 33-36962 and 811-6175
Dear Sir/Madam:
On behalf of the MainStay Institutional Funds Inc., a registered
management investment company (the "Company"), we hereby certify that, pursuant
to Rule 497(j) under the Securities Act of 1933 (the "Act"), the forms of
prospectuses that would have been filed under Rule 497(c) on behalf of the
Company do not differ from those contained in the Company's most recent post-
effective amendment, Post-Effective Amendment No. 18 filed April 30, 1998. The
text of Post Effective Amendment No. 18 was filed electronically (accession no.
0000950130-98-002244). The definitive form of the Company's Statement of
Additional Information is being filed pursuant to Rule 497(c) under the Act.
Please do not hesitate to contact Jennifer B. McHugh at (202) 261-3370
or the undersigned at (202) 261-3314 if you have any questions regarding the
above.
Sincerely,
/s/ Jeffrey L. Steele
Jeffrey L. Steele
