Regional banking powerhouse M&T Bank Corp. will acquire Baltimore-based Provident Bankshares Corp. for $401 million in M&T stock.

Under the agreement, Provident common shareholders will receive 0.171625 shares of M&T common stock in exchange for each share of Provident common stock, or $10.25 a share, based on M&T's Thursday's closing stock price of $59.72.

Market experts believe that the deal will give M&T the second-largest deposit share in Maryland, and will triple M&T's presence in Virginia.

Post acquisition, will add 143 Provident branch offices primarily in Maryland and Virginia, adding to M&T's current 177 branches in the region.

The boards of directors of both banks approved the deal, which is subject to regulatory and shareholder approval. It is expected to close late in the second quarter of 2009.