The agreements will take both players through the 2020-21 season.
Bitten was the Canadiens' third-round pick (70th overall) at the 2016 Draft.
The 19-year-old is in his fourth season in the Ontario Hockey League, and has recorded 61 points (19G, 42A) in 58 games with the Hamilton Bulldogs in 2017-18.
As for Pezzetta, also 19, he was the Habs' sixth-round pick (160th overall) at the 2016 Draft. The Toronto native was named captain of the OHL's Sudbury Wolves at the start of this season, but was traded to the Sarnia Sting in January.
The 6-foot-1, 212-pound pivot is in his fourth year of Junior, and has recorded 50 points (22G, 28A) in 58 games with the Wolves and Sting in 2017-18.
