M&T Bank

(MTB) - Get Report

is getting a new CEO.

The Buffalo, N.Y.-based bank says CEO Robert Sadler Jr. is stepping down at year's end. His successor will be the bank's current chairman, Robert Wilmers.

Sadler, who will remain a director of the bank and become vice chairman, notified the lender's board of his decision on Nov. 21.

The job changes will take effect on Jan. 1, 2007.

Allied Irish Banks

owns 24% of M&T Bank. The lender's second-biggest shareholder is Warren Buffett's

Berkshire Hathaway

( BRKA) conglomerate.