Chicago Blackhawks forward Andrew Shaw was suspended one game and fined US$5,000 on Wednesday after a penalty-box outburst in which he used a homophobic slur in a rant directed at game officials.

"While Mr. Shaw was both apologetic and remorseful for both the offensive comments and the inappropriate gesture directed at the on-ice officials, he must be held accountable for his actions," said NHL Vice President of Hockey Operations Colin Campbell.

"The emotion of the moment cannot and will not be a mitigating factor for the conduct that is expected of an NHL player."

Shaw had been unrepentant on Tuesday night immediately after the Blackhawks' 4-3 playoff loss to the St. Louis Blues, but said Wednesday that a later look at the video of himself was enough for him to know he owed an apology.

"I am sincerely sorry for the insensitive remarks that I made last night while in the penalty box," Shaw said in a statement released through the Blackhawks.

"When I got home and saw the video, it was evident that what I did was wrong, no matter the circumstances. I apologise to many people, including the gay and lesbian community, the Chicago Blackhawks organisation, Blackhawks fans and anyone else I may have offended.

"I know my words were hurtful and I will learn from my mistake," added Shaw, who will also be required to undergo sensitivity training.

Shaw was incensed when he was sent to the penalty box for interference with 2:04 left in the third period.

Chicago were down 4-3 and needed a victory to level the series at two games apiece.

He pounded the glass with his stick, gestured with his gloved hand and shouted at game officials.

Shaw will miss game five of the Blackhawks' best-of-seven first-round series at St. Louis on Thursday, when the Blues will be trying to close out the victory.