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                       SECURITIES AND EXCHANGE COMMISSION

                              Washington, D.C 20549



                                    FORM 8-K



                                 CURRENT REPORT



     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934



Date of Report (Date of earliest event reported):  May 16, 2000
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                              M&T BANK CORPORATION
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             (Exact name of registrant as specified in its charter)



                                    New York
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                 (State or other jurisdiction of incorporation)



            001-9861                                   16-0968385
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     (Commission File Number)              (I.R.S.Employer Identification No.)


                 One M&T Plaza, Buffalo, New York          14203
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            (Address of principal executive offices)    (Zip Code)



Registrant's telephone number, including area code:  (716) 842-5445
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                                (NOT APPLICABLE)
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          (Former name or former address, if changed since last report)


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Item 5.  Other Events.

         On May 17, 2000, M&T Bank Corporation announced that it had entered
into a definitive agreement with Keystone Financial, Inc. ("Keystone"),
Harrisburg, Pennsylvania, pursuant to which Keystone, a bank holding company,
will be acquired by M&T Bank Corporation upon the satisfaction of a number of
conditions. Upon consummation of the transaction, Keystone Financial Bank, N.A.,
Keystone's national bank subsidiary, will be merged into Manufacturers and
Traders Trust Company ("M&T Bank"), M&T Bank Corporation's principal commercial
bank subsidiary.

         Keystone Financial Bank, N.A. operates 171 banking offices in 33
counties in Pennsylvania, 25 banking offices in three counties in Maryland, and
three banking offices in one county in West Virginia. At March 31, 2000,
Keystone reported approximately $7.0 billion in assets. Keystone's common stock
is registered pursuant to Section 12(g) of the Securities Exchange Act of 1934,
as amended (File No. 000-11460). Additional information concerning Keystone is
on file with the Securities and Exchange Commission.

         Each share of Keystone common stock outstanding at the time the Merger
is consummated will, at the election of the holder thereof, be converted in to
either 0.05 of a share of common stock of M&T Bank Corporation (and cash in lieu
of fractional shares) or the right to receive $21.50 in cash as provided in the
Agreement and Plan of Merger, dated as of May 16, 2000, by and among Keystone,
M&T Bank Corporation, and M&T Bank Corporation's wholly owned subsidiary,
Olympia Financial Corp. ("Olympia"), providing for the merger (the "Merger") of
Keystone with and into Olympia (the "Plan of Merger"). The Plan of Merger is set
forth as Annex A to the Agreement and Plan of Reorganization (the
"Reorganization Agreement" and, together with the Plan of Merger, the "Merger
Agreements"), dated as of May 16, 2000, by and among M&T Bank Corporation,
Keystone and Olympia. A copy of the Reorganization Agreement is filed as Exhibit
2 hereto and is incorporated herein by reference. Subject to possible
adjustments set forth in the Plan of Merger, the total number of shares of
Keystone common stock to be exchanged for shares of common stock of M&T Bank
Corporation shall be 65% of the 48,930,000 shares of Keystone common stock
outstanding on May 16, 2000. Keystone shareholder elections to receive shares of
common stock of M&T Bank Corporation or cash are subject to the allocation and
proration procedures set forth in the Plan of Merger.

         In addition, in connection with the Merger, M&T Bank Corporation
intends to declare a 10-for-1 split on its common stock, and to increase the
cash dividend payable on its common stock after the transaction to $2.50 per
quarter on each pre-split share.

         Consummation of the transaction is subject to a number of conditions,
including regulatory approvals and the approval of M&T Bank Corporation's and
Keystone's respective stockholders. Subject to the satisfaction of all
conditions, it is anticipated that the transaction will be completed in late
2000.

         Following the consummation of the transaction, Mr. Carl L. Campbell,
chairman, president and chief executive officer of Keystone, will be elected
vice chairman and a director of each of M&T Bank Corporation and M&T Bank. Four
other directors of Keystone will join Mr. Campbell on M&T Bank Corporation's and
M&T Bank's boards of directors. Mr. Robert G. Wilmers will continue as president
and chief executive officer of M&T Bank Corporation and chairman of M&T Bank.





                                     - 2 -


         In connection with the execution and delivery of the definitive
agreement described above, Keystone granted M&T Bank Corporation a stock option
(the "Stock Option") to acquire up to 19.9% of the outstanding shares of
outstanding common stock of Keystone under certain conditions. A copy of the
Stock Option Agreement, dated as of May 16, 2000, by and among M&T Bank
Corporation and Keystone granting the Stock Option is filed as Exhibit 99.1
hereto and is incorporated herein by reference.

         The press release and analysts presentation issued by M&T Bank
Corporation and Keystone with respect to the announcement of the transaction
described herein are filed as Exhibits 99.2 and 99.3, respectively, hereto and
incorporated herein by reference. Each of the press release and analysts
presentation contains forward-looking statements with respect to the financial
condition, results of operations and business of M&T Bank Corporation and,
assuming the consummation of the merger, a combined M&T Bank
Corporation/Keystone, including statements relating to: (a) the cost savings and
accretion to reported earnings that will be realized from the merger; (b) the
impact on revenues of the merger, and (c) the restructuring charges expected to
be incurred in connection with the merger. These forward-looking statements
involve certain risks and uncertainties. Factors that may cause actual results
to differ materially from those contemplated by such forward-looking statements
include, among others, the following possibilities: (1) expected cost savings
from the merger cannot be fully realized or realized within the expected time
frame; (2) revenues following the merger are lower than expected; (3)
competitive pressure among depository institutions increases significantly; (4)
costs or difficulties related to the integration of the business of M&T Bank
Corporation and Keystone are greater than expected; (5) changes in the interest
rate environment reduce interest margins; (6) generally economic conditions,
either nationally or in the states in which the combined company will be doing
business, are less favorable than expected; or (7) legislation or regulatory
requirements or changes adversely affect the business in which the combined
company would be engaged.

         The foregoing descriptions of and references to all of the
above-mentioned agreements and documents are qualified in their entirety by
reference to the complete texts of the agreements and documents that are filed
herewith and incorporated herein by reference.


Item 7.  Financial Statements and Exhibits

The following exhibits are filed herewith or incorporated herein by reference:


Exhibit No.
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    2       Agreement and Plan of Reorganization dated as of May 16, 2000, by
            and among M&T Bank Corporation, Olympia Financial Corp. and
            Keystone Financial, Inc. (including the Plan of Merger as Annex A
            thereto).

    99.1    Stock Option Agreement dated as of May 16, 2000 by and between M&T
            Bank Corporation and Keystone Financial, Inc.

    99.2    Joint Press Release, dated May 17, 2000.

    99.3    Analysts Presentation.






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                                   SIGNATURES






         Pursuant to the requirements of the Securities Exchange Act of 1934,
the registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.



                                            M&T BANK CORPORATION




Date: May  23, 2000                         By:  /s/Michael P. Pinto
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                                                   Michael P. Pinto
                                                   Executive Vice President and
                                                   Chief Financial Officer






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                                 CURRENT REPORT



Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934



Report Dated: May 16, 2000                  Commission File Number: 001-9861
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                              M&T BANK CORPORATION
             (Exact name of registrant as specified in its charter)


                                    EXHIBITS









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                                  EXHIBIT INDEX


Exhibit No.
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    2       Agreement and Plan of Reorganization dated as of May 16, 2000, by
            and among M&T Bank Corporation, Olympia Financial Corp. and Keystone
            Financial, Inc. (including the Plan of Merger as Annex A thereto).
            Filed herewith.

    99.1    Stock Option Agreement dated as of May 16, 2000 by and between M&T
            Bank Corporation and Keystone Financial, Inc. Filed herewith.

    99.2    Joint Press Release, dated May 17, 2000. Filed herewith.

    99.3    Analysts Presentation. Filed herewith.