Updated

New York, NY (SportsNetwork.com) - National Hockey League commissioner Gary Bettman has upheld the 15-game suspension issued to Boston Bruins forward Shawn Thornton.

Bettman heard Thornton's appeal at a hearing in the league's U.S. headquarters this past Friday, and issued a 12-page decision on Tuesday.

"In this case there is no dispute that Mr. Thornton's conduct was in violation of Rule 46.15 and warranted a match penalty. The NHLPA does not dispute that a lengthy suspension was warranted. The only question raised by this appeal is the appropriate length of the penalty, which the Union contends should be reduced from fifteen (15) games to somewhere in the range of 10-12 games. I find that there is clear and convincing evidence to support Mr. Shanahan's conclusion that a suspension of fifteen (15) games is appropriate," Bettman wrote.

The NHL's Department of Player Safety issued its harshest punishment of the season thus far to the 36-year-old Thornton for his attack on Pittsburgh Penguins defenseman Brooks Orpik during a Dec. 7 meeting between the teams in Boston.

The veteran enforcer was also in line to forfeit $84,615.45 in salary for his actions.

Under the terms of the current Collective Bargaining Agreement, now that Bettman has heard his initial appeal, Thornton can also take his grievance to an independent arbitrator.

"We respect the process including the ability to attend the hearing with Commissioner Bettman in support of Shawn," said Bruins GM Peter Chiarelli in a statement. "At this time, we will decline comment until the process is complete and Shawn has exhausted all rights available to him."