The Bruins will officially lose one of their key front office members as longtime assistant general manager Jim Benning has agreed to a multi-year deal to become the GM of the Vancouver Canucks, according to TSN’s Darren Dreger. Benning was granted permission to interview for the Canucks’ top executive job in hockey operations after a meeting last month between Cam Neely and new Canucks President Trevor Linden, and reports this week had him a fait accompli for the job.

The official announcement is expected to take place on Friday in Vancouver, and that leaves the Bruins with fellow assistant general manager Don Sweeney alongside GM Peter Chiarelli. Sources had indicated to that Sweeney was under serious consideration for the vacant GM job with the Washington Capitals, but it’s unclear if the Bruins would allow him to leave his Boston post with Benning already leaving the B’s front office.

Benning joined Chiarelli with the Bruins in 2007, and played a major role in drafting and developing a raft of Bruins prospects that have become the nucleus for the 2011 Stanley Cup winning team. Prior to joining the Boston front office, Benning was the director of scouting for the Buffalo Sabres after a long NHL career where he oversaw the selection of Ryan Miller, Jason Pominville, Derek Roy, Daniel Paille and Dennis Wideman among others, and played a major role in both Wideman and Paille eventually coming to Boston.