Pacific Capital Bancorp, the holding company for Santa Barbara Bank & Trust, said it agreed to buy Los Robles Bancorp in a cash deal of $32.5 million, or $23.12 a share, to expand into the suburban Los Angeles market. Los Robles has $149 million in assets, three banking offices in Thousand Oaks, Westlake Village and Camarillo and two loan offices. Santa Barbara-based Pacific Capital, which is also the holding company for First National Bank of Central California, had assets of $2.78 billion at the end of last year. The acquisition will add to Pacific Capital's earnings in the first full year of operations, the company said. Los Robles will eventually take the name of Santa Barbara Bank & Trust. Shares in Thousand Oaks-based Los Robles rose $3.25 to close at $22 in over-the-counter trading.