For more information, please contact:

Elizabeth Braungard                                 Jacquelyn Basso
VP, Director of Marketing                           VP, Director of Marketing
(Delivery Services)                                 (Support Services)
(717) 231-5732                                      (717) 231-5723



September 5, 2000

Keystone Financial Shareholders Approve M&T Bank Merger

         Harrisburg,  PA - Keystone Financial Inc., (NASDAQ:KSTN)  ("Keystone"),
announced that, at its special  meeting of shareholders  held September 5, 2000,
it  received   approval  of  the  proposed  merger  with  M&T  Bank  Corporation
(NYSE:MTB)("M&T"). Approximately 91.4% of shares voted were cast in favor of the
proposed merger.

         A special meeting for M&T shareholders will be held at M&T Center,  One
Fountain  Plaza,  Buffalo,  New York on Tuesday,  September  19, 2000 at 11 a.m.
local  time to vote on the  proposed  merger and a charter  amendment  that will
facilitate a proposed 10-for-1 split of M&T's common stock.

         Completion  of  the  merger  is  anticipated  in  early  October.   The
appropriate governmental approvals have been received. Under terms of the merger
agreement, stockholders of  Keystone have the option, subject to the  allocation
and proration provisions  of the  agreement,  of  electing to receive .05 shares
of M&T common stock or $21.50  in cash in exchange for each outstanding share of
Keystone  common  stock.  The  deadline  for receipt of all  required  documents
regarding shareholders' elections by the exchange  agent is no later than 5 p.m.
New York City time, on Wednesday, September 20, 2000.

         The merger  will  create a bank with  approximately  450 offices in New
York,  Pennsylvania,   Maryland  and  West  Virginia,  and  combined  assets  of
approximately  $30 billion.  M&T Bank will become the 29th  largest  independent
banking company in the United States.

         "With this merger,  Keystone joins forces with a financial  institution
that  has  a  proven  track  record  of  creating  exceptional  value  for  it's
shareholders,  a  dedication  to  customer  service  and  a  commitment  to  the
communities  it  serves,"  stated  Keystone  Chairman,  President  and CEO  Carl
Campbell.

         Keystone,  the fourth largest  financial  institution-headquartered  in
Pennsylvania with assets of approximately $7 billion, is the holding company for
Keystone  Financial  Bank,  N.A.,  which has more than 175 community  offices in
Pennsylvania,   Maryland  and  West  Virginia.   For  more  information,   visit
www.e-keystonefinancial.com. or www.mandtbank.com on the internet.