Irvine-based Banc of California Inc. has agreed to buy the California branch network of Popular Community Bank for $5.4 million.

Banc of California had about $3.6 billion in total assets as of the end of last year and is among the largest banks headquartered in Orange County.

The acquisition includes 20 Popular Community retail branches, more than $1 billion in deposits and about $1.1 billion in assets. The deal is expected to boost Banc of California’s assets to more than $5 billion, which would put it atop the OC rankings and bring its total number of office and branch locations to more than 100.

Popular Community is the U.S. operating franchise of San Juan, Puerto Rico-based Popular Inc. The parent company also is divesting its operations in Illinois and Central Florida in a move to “optimize invested capital by concentrating on New York and South Florida.”

Banc of California Chief Executive Steven Sugarman said the deal will help “expand our footprint throughout Los Angeles and Orange County, and to strengthen our capabilities to serve California’s fast-growing Latino community.”

The bank last year tapped former L.A. Mayor Antonio Villaraigosa as strategic adviser to emphasize its focus on the market.

Banc of California has partnered with investment funds managed by Los Angeles-based Oaktree Capital Management LP and Patriot Financial Partners in Philadelphia, which have agreed on equity purchase agreements as part of the acquisition.

The transaction is expected to be completed in the fourth quarter.