MONTREAL - The NHL could lose Air Canada as a sponsor if it doesn't take action to curb headshots.

However NHL commissioner Gary Bettman responded to sponsorship concerns Thursday afternoon by saying that the league will not budge on its stance towards spiraling violence.

On Tuesday Air Canada's director of marketing Denis Vandal sent a letter to the league saying it will pull its support of the NHL if something isn't done to prevent the dangerous incidents that have been cropping up.

The move comes following a decision by the league not to discipline Boston Bruins defenceman Zdeno Chara for a crushing hit on Montreal Canadiens forward Max Pacioretty.

Pacioretty was released from hospital Wednesday afternoon after being treated for a severe concussion and a non-displaced fracture of the fourth cervical vertebra.

The 22-year-old said he's "disgusted" that the NHL didn't suspend Chara for the hit.

"I am upset and disgusted that the league didn't think enough of (the hit) to suspend him," Pacioretty told TSN's Bob McKenzie Wednesday.

Chara, who said he had no intent to hurt Pacioretty, was given a major penalty for interference and a game misconduct for the hit.

Part of the game: Bettman

NHL commissioner Gary Bettman says there's no need to "over-legislate'' head hits.

Speaking after a U.S. congressional panel discussion Thursday on encouraging American kids to get into hockey, Bettman pointed to a trend this season.

"What's interesting ... is that the rise in concussions in the preliminary data from this season seem to be coming from accident events, collisions, players falling and banging into other things, not from head hits,'' he told reporters.

As for Air Canada threatening to pull its sponsorship over such injuries, Bettman said the league can find other carriers if Air Canada doesn't want the NHL's business.

"Air Canada is a great brand, as is the National Hockey League, and if they decide they need to do other things with their sponsorship dollars that's their prerogative, just like it's the prerogative of our clubs that fly on Air Canada to make other arrangements if they don't think Air Canada is giving them the appropriate level of service.''

Concussions a major concern

The letter from Air Canada comes amid heightened concern about concussions in the National Hockey League.

Superstar Sidney Crosby remains on the sidelines after taking a serious hit during the NHL's Winter Classic in early January. Crosby returned following the game and was checked into the boards again four days later. He hasn't returned to the ice since.

Next week, when the NHL's general managers hold their annual meeting, the issue of how to handle concussions in players is expected to be a hot topic of discussion.

The news last week that former NHL enforcer Bob Probert had a degenerative brain disease has also stirred a debate about the safety of fighting in hockey.

with files from The Canadian Press