Montreal police started a criminal investigation Thursday into theon-ice hit by Boston's Zdeno Chara that left the Canadiens' MaxPacioretty with a severe concussion and cracked verterbra.Police said they are acting on a request by Quebec's director ofcriminal and penal prosecutions, Louis Dionne. Police added that afterevidence is collected it will then be determined if there are groundsfor prosecution.The NHL said a day earlier it would not suspend Chara for Tuesdaynight's hit, when he slammed Pacioretty into a glass partition.NHL Commissioner Gary Bettman declined to comment Thursday while onhis way to a congressional briefing in Washington, D.C. focusing on thestate of hockey in America.There has been strong debate this season over injuries from hits tothe head. Pittsburgh star Sidney Crosby is among those sidelined withsuch an injury.In a related matter, Air Canada has told the NHL it is consideringwithdrawing its sponsorship unless the league tightens rules to reducepotentially serious injuries.Dionne filed his request for an investigation after watching television footage of Chara's hit, his spokeswoman said."The police investigation will be held. Like all policeinvestigations, evidence will be gathered and an investigation reportwill be submitted, spokeswoman Martine Berube said. "(The DCPP) willthen evaluate to see whether there's grounds for prosecution.''Asked what kind of punishment could be assessed in a case likeChara's, she replied: "It's too early to say. That would depend on whatcharges are laid. That's a little difficult to predict at this point.''Pacioretty, a left wing from Connecticut, is a regular top-lineplayer for Montreal. With he and Chara racing for the puck near theplayer benches, Chara checked Pacioretty into the boards, sending himslamming into a stanchion supporting the glass.The hit drew criticism from Gary Lunn, the minister of state forsports, and others outside the league. Lunn called it unacceptable.But the league deemed it "a hockey play that resulted in an injurybecause of the player colliding with the stanchion and then the icesurface.''