California United Bank of Encino on Wednesday said it reached an agreement to acquire California Oaks State Bank of Thousand Oaks for $17.3 million.

California United said about half the acquisition price will be paid in cash and the rest in shares of California United common stock. Upon completion, California United Bank would have more than $650 million in assets and $530 million in deposits. The transaction is expected to be immediately accretive to its earnings per share in 2011 and 2012, it said.

California Oaks shareholders will receive about $11.35 per share if the transaction closes by Dec. 31 or $11.30 per share if the transaction closes after that date, in the form of stock, cash or a combination of cash and stock.

The total purchase price represents a 39 percent premium to the market capitalization of California Oaks before the announcement.

California United Bank plans to continue to operate both California Oaks locations as full-service branches. At close, California United will have six full-service branches in Los Angeles, Orange and Ventura counties.

“The combination is expected to create one of the largest banks headquartered in the San Fernando Valley and presents significant prospects for our communities and shareholders,” California United Chief Executive David Rainer said in a statement.

The merger has been unanimously approved by both boards but still must be approved by shareholders and bank regulators. The deal is expected to close in the fourth quarter.

The stock of both banks trades on the over-the-counter Bulletin Board. California United shares closed down 10 cents, or less than a percent, to $10.95 and California Oaks jumped $4, or 66 percent, to $10.