Bruins general manager Peter Chiarelli announced the deal Tuesday afternoon.
Savard's average annual salary on the Bruins' salary cap will be a little more than $4 million. The deal is front-loaded so Savard will make most of the money in the early years, sources told LeBrun.
Savard will make $7 million for each of the first two seasons of the extension, $6.5 million the third season and $5 million the fourth season. His salary will then drop to $1.5 million for the 2014-15 season and $525,000 for each of the final two years of the deal.
He will be approaching his 40th birthday when the contract expires.
Savard, who recently returned from a broken foot and has four goals and six assists in 11 games this season, was unavailable for comment after practice, according to a Bruins media relations official.
The two-time All-Star is in the final season of a four-year contract that pays him $5 million a year. He was eligible to become an unrestricted free agent after this season.
Last season, Savard led the Bruins in scoring with 88 points, and has averaged 67 assists and almost 90 points per year over the last four seasons. He also led the team in playoff scoring the past two years while making the last two All-Star Games.
The Associated Press contributed to this story.