The 36-year-old was eligible to become a an unrestricted free agent on July 1. He reportedly is to earn US$2.25 million, the same salary he earned the last two seasons with the Canadiens.
Gill had only two goals and seven assists in 75 games last season, but his strengths are his defensive play and shot blocking. He was also a solid mentor for gifted rookie P.K. Subban.
The Concord, Mass., native, who won a Stanley Cup with Pittsburgh in 2008, has 35 goals and 136 assists in 994 games with Boston, Toronto, Pittsburgh and Montreal.
The deal is being reported by various media outlets.