A hockey source has confirmed to The Bruins Blog that the Bruins and defenseman Andrew Ference have agreed to terms on a three-year contract extension. UPDATE: The Bruins announced the deal at 11 a.m. The deal calls for a cap hit of $2.25 million per season, as per a source.

Ference, 31, was scheduled to become an unrestricted free agent this summer. While his stint in Boston since 2007 has been marred by injury — he’s even playing through a groin injury that will require offseason surgery — Ference has been a solid member of the club’s top four when healthy. This season in 50 games, Ference has posted eight assists and a minus-7 rating.

The Ference signing means the Bruins have four of their current seven defensemen under contract for next season, with Dennis Seidenberg scheduled to be a UFA and Mark Stuart and Johnny Boychuk ticketed for restricted free agency. Ference currently carried a $1.4 million cap hit, so his new deal provides a significant raise.