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                                                                    EXHIBIT 4.15

                AMENDMENT TO AMENDED AND RESTATED TRUST AGREEMENT

                  This Amendment to Amended and Restated Trust Agreement (the
"Amendment") is made as of December 17, 1999 by the Administrative Trustees of
the trust created under that certain Amended and Restated Declaration of Trust
described below.

                                   WITNESSETH

                  WHEREAS, Olympia Financial Corp., formerly known as ONBANCorp,
Inc. (the "Sponsor"), The Bank of New York, as property trustee, (in such
capacity, the "Property Trustee" and, in its separate corporate capacity and not
in its capacity as Property Trustee, the "Bank"), and The Bank of New York
(Delaware), a Delaware banking corporation, as Delaware trustee (the "Delaware
Trustee") previously entered into an Amended and Restated Declaration of Trust
of OnBank Capital Trust I dated as of February 4, 1997 (the "Trust
Declaration"); and

                  WHEREAS, ONBANCorp, Inc. has been merged with and into Olympia
Financial Corp., a wholly owned subsidiary of M&T Bank Corporation, a New York
corporation; and

                  WHEREAS, the Administrative Trustees of the Trust have changed
the name of the Trust from "OnBank Capital Trust I" to "M&T Capital Trust III;"
and

                  WHEREAS, the Administrative Trustees of the Trust desire to
further amend the Trust Declaration to provide for the change of the the Sponsor
from "ONBANCorp, Inc." to "Olympia Financial Corp.," and the name of the Trust
from "OnBank Capital Trust I" to "M&T Capital Trust III."

                  NOW THEREFORE, in consideration of the agreements and
obligations set forth herein and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, each party to this
Amendment, for the benefit of the other parties and for the benefit of the
Holders, hereby amends the Trust Declaration, and agrees, intending to be
legally bound, as follows:

SECTION 1.  DEFINITIONS.

                  1.1. For all purposes of this Amendment, except as otherwise
expressly provided, terms used but not defined in this Amendment shall have the
meanings assigned to them in the Trust Declaration.

                  1.2. The definition of "Trust" in the preamble of the Trust
Declaration is amended to mean M&T Capital Trust III.

                  1.3. The definition of "Debenture Issuer" in section 1.1 of
the Trust Declaration is amended to read as follows:


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                  "DEBENTURE ISSUER" means Olympia Financial Corp., a Delaware
                  Corporation, or any successor entity resulting from any
                  consolidation, amalgamation, merger or other business
                  combination, in its capacity as issuer of the Debentures under
                  the Indenture.

                  1.4.  The definition of "Sponsor" in Section of 1.1 of the
Trust Declaration is amended to read as follows:

                  "SPONSOR" means Olympia Financial Corp., a Delaware
                  Corporation, or any successor entity resulting from any
                  consolidation, amalgamation, merger or other business
                  combination, in its capacity as sponsor of the Trust.

SECTION 2.  MISCELLANEOUS.

                  2.1. CONTINUING AGREEMENT. The Trust Declaration shall not be
amended by this Amendment except as specifically provided in this Amendment and,
amended as so specifically provided, the Trust Declaration shall remain in full
force and effect. References in the Trust Declaration to "this Declaration"
shall be deemed to be references to the Trust Declaration as amended by this
Amendment.

                  2.2. CONFLICTS. In the event of a conflict between the terms
and conditions of the Trust Declaration and the terms and conditions of this
Amendment, the terms and conditions of this Amendment shall prevail.

                  2.3. COUNTERPART ORIGINALS. The parties may sign any number of
copies of this Amendment. Each signed copy shall be an original, but all of them
together represent the same agreement.

                  2.4. HEADINGS, ETC. The headings of the sections of this
Amendment have been inserted for convenience of reference only, are not to be
considered a part hereof, and shall in no way modify or restrict any of the
terms or provisions hereof.

                  IN WITNESS WHEREOF the parties have caused this Amendment to
be executed as of the day and year first above written.

 /S/ DARLENE A. SPYCHALA                               /S/ TIMOTHY G. MCEVOY
---------------------------                           --------------------------
Darlene A. Spychala                                   Timothy G. McEvoy
Administrative Trustee                                Administrative Trustee

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