The merger has been approved by the Federal Deposit Insurance Corporation, the Federal Reserve Bank of San Francisco and the California Department of Business Oversight.
Under the agreement, National Bank of California will be merged into Commercial Bank of California.
The combined bank will continue to operate under the name Commercial Bank of California as a subsidiary of NCAL Bancorp.
It will continue to serve its customer base in Los Angeles County and Orange County.
All existing branches of both banks will remain open following the merger. The bank has also secured approval to open a full-service branch in Santa Monica, which is expected to be inaugurated in the second quarter of this year.
The combined bank will have total assets of more than $750m and total deposits of over $650m on a pro forma basis, depending on financial information as of 31 December 2015.
The transaction is expected to be completed on or about 30 April 2016.
NCAL Bancorp and National Bank of California chairman of the board and Commercial Bank of California CEO Ash Patel said: "The merger of Commercial Bank of California and National Bank of California provides an opportunity to create the foundation for a privately held, billion dollar bank offering customers of Los Angeles and Orange Counties access to greater financial resources."
Image: National Bank of California will be merged into Commercial Bank of California. Photo: courtesy of adamr/FreeDigitalPhotos.net.