Somerville-based Central Bank has been purchased by Rockland Trust, according to a press release issued Tuesday morning.

The Central Bank location at Four Corners—and all eight other locations—will remain open as a Rockland Trust branch, a company spokeswoman said Tuesday. The sale will cost Rockland Trust's parent company Independent Bank Corp about $55 million and is expected to be finalized by the end of the year.

Central Bank was established in 1915. It operates branches in Arlington, Burlington, Chestnut Hill, Malden, Medford, Melrose, Somerville and Woburn.