Officials at Tacoma-based Columbia Bank and Lake Oswego, Ore.-based West Coast Bancorp jointly announced Wednesday that the companies have agreed to combine their two Pacific Northwest community bank franchises in a transaction valued at approximately $506 million. The combined company will have approximately $7.2 billion in assets with over 150 branches throughout Washington and Oregon.

“We are very pleased that West Coast has agreed to join and grow with Columbia,” said Melanie J. Dressel, President and Chief Executive Officer of Columbia Bank. “We see this as an exciting opportunity for both companies, our shareholders, customers and employees to create the premier community banking franchise in the Pacific Northwest. On a combined basis, we will have extensive coverage throughout Washington and Oregon.”

Robert D. Sznewajs, President and Chief Executive Officer of West Coast commented, “This merger is a rare fit of two high quality organizations with similar business models, cultures and values. We think the transaction will provide outstanding benefits to our customers, communities, shareholders, and other constituencies, along with enhancing our proven approach to community banking.”

The transaction is expected to be completed in the first quarter of 2013, after obtaining the approval of the shareholders of each company and receipt of necessary regulatory approvals. The agreement was unanimously approved by the Board of Directors of each company.

Headquartered in Tacoma, Wash., Columbia Banking System, Inc. is the holding company of Columbia State Bank, a Washington state-chartered full-service commercial bank. Columbia Banking System has 101 banking offices, including 76 branches in Washington State and 25 branches in Oregon. Columbia Bank does business under the Bank of Astoria name in Astoria, Warrenton, Seaside, Cannon Beach, Manzanita and Tillamook in Oregon. More information about Columbia can be found online at columbiabank.com.

West Coast Bancorp is a publicly held, Northwest bank holding company headquartered in Oregon with $2.4 billion in assets, and the parent company of West Coast Bank and West Coast Trust Company, Inc. West Coast Bank operates 58 branches in Oregon and Washington. More information about West Coast Bancorp can be found online at wcb.com.