This image from Tuesday's game shows Montreal's Max Pacioretty hitting his head on the glass partition between the benches after a hard check by Boston's Zdeno Chara at the Bell Centre. A Quebec prosecutor wants police to investigate the hit by Chara that sent Pacioretty to the hospital with a fractured vertebra and severe concussion.

BOSTON — Montreal police started a criminal investigation Thursday into the on-ice hit by Boston’s Zdeno Chara that left the Canadiens’ Max Pacioretty with a severe concussion and cracked vertebra.

Police said they are acting on a request by Quebec’s director of criminal and penal prosecutions, Louis Dionne. After evidence is collected, it will be determined if there are grounds for prosecution, they said.

“I was disappointed that the NHL did not suspend Zdeno Chara. However, I have no desire for him to be prosecuted legally. I feel that the incident, as ugly as it was, was part of a hockey game,” Pacioretty said in a statement.

Also Thursday, Air Canada told the NHL it’s considering withdrawing its sponsorship unless the league tightens rules to reduce potentially serious injuries. Commissioner Gary Bettman responded that his teams could retaliate by deciding to stop using Air Canada for charter flights, an important source of revenue for the airline.

Chara did not speak at length on the investigation when he talked after the Bruins’ morning skate.

“I got some media information on that this morning,” he said. “But like I said, right now, I’m focusing on playing my game, and playing hockey.”

Chara, who said he had no intent to hurt Pacioretty, was given a major penalty for interference and a game misconduct on the play Tuesday. The Bruins captain has never been suspended in his 13-year career.

The NHL said Wednesday it would not suspend Chara for slamming Pacioretty into a padded stanchion supporting a glass partition. Pacioretty, 22, was released from the hospital Thursday and was resting at home, his agent said.

Among Thursday’s other developments:

n In Toronto, Canadian Prime Minister Stephen Harper said the NHL, “for its own sake,” should look seriously at the increase in serious injuries.

n NHL Players’ Association executive director Don Fehr called for “maximizing the safety” in the area of the rink where the hit occurred and said the union would inspect the rink in Montreal “and elsewhere as needed, to make sure the appropriate padding is in place.”