Los Angeles-based Mattress Gallery, which owns and operates 53 mattress stores in Southern California, is set to be purchased by Houston-based Mattress Firm, the number three retailer of mattresses with 450 stores in 21 states.

Upon completion of the purchase of Mattress Gallery, Mattress Firm will enter the California market for the first time and become the number two mattress retailer ahead of Select Comfort.

Financial terms of the acquisition, which is expected to close in 60 days, were not disclosed.

Mattress Gallery stores will be converted into Mattress Firm stores, and will expand product selection.