Exhibit 23.5

                   CONSENT OF SANDLER O'NEILL & PARTNERS, L.P.

         We hereby consent to the inclusion of our opinion letter to the Board
of Directors of FNB Rochester Corp. (the "Company") as Appendix C to the Proxy
Statement-Prospectus relating to the proposed merger of the Company with and
into Olympia Financial Corp., a wholly-owned subsidiary of M&T Bank Corporation,
contained in the Registration Statement on Form S-4, as filed with the
Securities and Exchange Commission on the date hereof, and to the references to
our firm and such opinion in such Proxy Statement-Prospectus. In giving such
consent, we do not admit that we come within the category of persons whose
consent is required under Section 7 of the Securities Act of 1933, as amended
(the "Act"), or the rules and regulations of the Securities and Exchange
Commission thereunder (the "Regulations"), nor do we admit that we are experts
with respect to any part of such Registration Statement within the meaning of
the term "experts" as used in the Act or the Regulations.


                                                 /s/ Sandler O'Neill & Partners
                                                 ------------------------------
                                                 Sandler O'Neill & Partners L.P.
March 31, 1999