Newton-based New England Development has sold an 85,788-square-foot office building at 1 Wells Ave. in Newton to William James College for $18 million.

The college, which hosts New England’s largest graduate psychology program, leased the first three floors in August 2012 and occupied the remaining two floors beginning in July. The additional space is being used for offices, classrooms and conference rooms.

Transwestern RBJ represented the college in the transaction. Tax-exempt financing for the purchase was provided by East Boston Savings Bank through SJ Advisors.