Irvine-based Opus Bank today completed its acquisition of RMG Capital Corp. and its subsidiary Fullerton Community Bank.

The deal adds about $636 million in assets for Opus Bank, bringing its total to more than $2.5 billion. It is the largest bank based here.

Fullerton Community Bank’s seven offices, all in North Orange County, are now open as Opus Bank.

Tom Meyer, former chairman of RMG and Fullerton Community Bank, will serve as president of Opus Bank’s OC region, according to a statement.

The bank now has 37 banking offices throughout Southern California and the Seattle area.

Opus Bank has plans to open new offices in Laguna Niguel, West Los Angeles and Del Mar, according to Chief Executive Stephen Gordon.

“We’re spreading the footprint by opening locations where people want us,” Gordon said. “Now is exact the right time for a bank to be growing and expanding its client base. Clients really need the banking industry to be there right now.”