Sun Life Retirement plans move to 31 St. James Ave.

Sun Life Retirement Services has signed a sublease for 70,765 square feet of office space at 31 St. James Ave. in Boston, the broker that represented Sun Life in the transaction said today.

The broker is Grubb & Ellis Co., a real estate services and investment management firm.

Sun Life Retirement Services, which is currently located at 500 Boylston St., plans on relocating to its new offices in the spring of 2008, Grubb & Ellis said.

Sun Life is subleasing the space from First Marblehead Corp., Grubb & Ellis said.

Based in Boston, First Marblehead provides private education loan services.

The Codman Company, a Boston real estate firm, represented First Marblehead in the transaction, Grubb & Ellis said.
(By Chris Reidy, Globe staff)