Mark Olson has resigned from his position as chief financial officer and executive vice president at Paso Robles-based Heritage Oaks Bancorp, tied as the largest bank based in the region with about $1.2 billion in assets.

The bank made the announcement Tuesday. It gave no reason for Olson’s departure, which takes effect on Jan. 31. He joined Heritage Oaks last year after serving as CFO at Pacific Capital Bancorp, the parent company of Santa Barbara Bank & Trust. Olson joined Heritage Oaks in March 2013, after SBB&T was purchased by Union Bank.

Heritage Oaks said that while searching for Olson’s successor, CEO Simone Lagomarsino will assume the title of interim CFO.

“It saddens me to announce that Mark will be leaving the bank,” Lagomarsino said in a news release. “During his time here, Mark has made numerous contributions to the growth and profitability of our organization. We appreciate all his hard work and wish Mark well in the next phase of his career.”