First PacTrust Bancorp Inc., the parent company to Pacific Trust Bank that moved its headquarters to Irvine from Chula Vista in March, received approval from the Federal Reserve Bank of San Francisco to become a bank holding company and soon will acquire Beach Business Bank in Manhattan Beach, the company said June 1.

The approval marks a milestone, according to CEO Greg Mitchell, because it is likely the first savings and loan holding company in the nation to convert to a bank holding company since the passage of the Dodd-Frank banking reform act.

It’s yet another change in the long history of First PacTrust, which began in 1941 as Rohr Employees Federal Credit Union. In 2000, the credit union converted to a mutually owned federal savings bank, and two years later the parent company issued stock.

Last year, First PacTrust, armed with an infusion of $60 million from new investors, agreed to buy Gateway Bancorp, based in Cerritos, and Beach. Regulators have yet to approve the Gateway transaction, but Mitchell said it should happen before the end of this month.

With the two new acquisitions, First PacTrust will have about $1.45 billion in total assets and 18 branches in San Diego, Orange, Los Angeles and Riverside counties.

In other news, the company declared a 12 cent cash dividend per common share that’s payable July 2 to investors of record as of June 15.