MANCHESTER, England -- The International Olympic Committee and two of Michael Phelps' leading sponsors expressed support for the Olympic great Monday, a day after he apologized for being photographed in a British newspaper inhaling from a marijuana pipe.

The IOC said Monday it was confident Phelps would learn from his "inappropriate behavior" and continue to serve as a role model.

Luxury Swiss watchmaker Omega termed Phelps' actions a private matter and "nonissue." Swim wear manufacturer Speedo called the 23-year-old American a "valued member of the Speedo team."

"Michael Phelps is a great Olympic champion," the IOC said in a statement e-mailed to The Associated Press. "He apologized for his inappropriate behavior. We have no reason to doubt his sincerity and his commitment to continue to act as a role model."

Phelps acknowledged "regrettable" behavior and "bad judgment" after the photo appeared Saturday in the tabloid News of the World.

Speedo gave Phelps a $1 million bonus for his record eight gold medals at the Beijing Olympics. Phelps joined Speedo in 2001, a year after making his Olympic debut in Sydney. He dominated the Beijing Games in the company's high-tech LZR Racer suit.

"In light of Michael Phelps' statement yesterday, Speedo would like to make it clear that it does not condone such behavior and we know that Michael truly regrets his actions," Speedo, which is based in Nottingham, said in a statement to The Associated Press.

"Michael Phelps is a valued member of the Speedo team and a great champion. We will do all that we can to support him and his family."

Omega said it was "strongly committed" to its relationship with Phelps, calling his Beijing accomplishments "among the defining sporting achievements in the history of sport."

"The current story in the press involves Michael Phelps' private life and is, as far as Omega is concerned, a nonissue," the company said.

Sports performance beverage PureSport's maker, which tapped Phelps to be spokesman for its first national advertising campaign, also said Monday that it stands by him but it said it does not condone his behavior.

"We applaud the fact that he has taken full and immediate responsibility for his mistake and apologized to us, his fans and the public and we support him during this difficult time," said Michael Humphrey, chief executive of Human Performance Labs.

Hilton Hotels Corp., whose relationship with Phelps dates to 2007, likewise stuck with him.

"We continue to support Michael Phelps as an athlete whose numerous athletic feats outshine an act of regrettable behavior," the statement said.

But former sponsor Rosetta Stone, the foreign-language tutorial vendor, which had a one-year deal with the athlete that ended Dec. 31, did not like the news.

"We do not condone his activities and are disappointed in his recent judgment," Rosetta Stone said in a statement.

Both AT&T Inc. and PowerBar nutrition bar makers Nestle SA, two other big sponsors, quietly ended their relationships with Phelps at the end of 2008. Neither company would comment on the photo or describe the duration or value of their contracts.

A spokesman at sports marketing agency Octagon, which represents Phelps, said the athlete is taking this seriously.

"He has spoken with his sponsors to personally apologize. We are encouraged by their support," the spokesman said.

The News of the World said the picture was taken during a November house party while Phelps was visiting the University of South Carolina.

Under World Anti-Doping Agency rules, an athlete is subject to sanctions only for a positive test during competition periods.

Information from The Associated Press was used in this report.