Sept 26 (Reuters) - Columbia Banking System Inc said it agreed to buy West Coast Bancorp in a deal valued at about $506 million, expanding its footprint in Washington and Oregon.
Columbia Banking said it would pay for the deal with $264.5 million in cash and 12.8 million shares.
West Coast shareholders can choose to receive payment in common stock, cash or a combination of the two.
Columbia said West Coast shareholders would receive about $23.10 per share, a 14 percent premium to the stock's Tuesday close.
Columbia's shares closed at $18.85 on the Nasdaq on Tuesday. West Coast's stock closed at $20.18.