The Chelmsford office of Century 21 Landmark Realty has merged with ERA Key Realty Services.

ERA Key’s seven agents formerly based at 61 Central Square will move to Landmark Realty’s office at One Chelmsford St., joining the 19 former Landmark agents.

ERA Key now has 16 offices throughout central and eastern Massachusetts and is the fourth largest agency in Massachusetts by number of homes sold. 

"This merger enables ERA Key to increase its presence in Chelmsford with an agency that has an ideal location, experienced agents and a great reputation," ERA Key President Bruce Taylor said in a statement. "That’s a winning combination that will benefit agents, homebuyers and home sellers."

Andrew Wilson, owner and manager of Century 21 Landmark Realty, will continue to serve as manager of the merged agency.

"I’ve always seen the manager’s role as being responsible for agents and helping them grow their businesses," Wilson said in a statement. "Now I will be able to focus more on that role. In addition, the merger will bring new technology and other resources to the agency, which will help our agents to better serve their clients."