Getting your Trinity Audio player ready...

Tiger Woods, admitting for the first time that he had been unfaithful to his wife, announced “an indefinite break from professional golf” on Friday, sending ripples of alarm through television networks, corporate sponsors, PGA executives and the rest of a multimillion-dollar industry that has been built around one of the world’s most bankable athletes.

Woods said the decision came “after much soul-searching,” and a realization that “it may not be possible to repair the damage I’ve done, but I want to do my best to try.” He didn’t say how long he intended to remain away from the sport, but added: “I need to focus my attention on being a better husband, father and person.”

The decision will have the most immediate impact on the PGA Tour, which already has been losing sponsorships and is in desperate need of his drawing power as it prepares to begin a new season next month.

“By himself, Tiger is probably 50 percent of golf,” said author John Feinstein, who writes frequently about the sport. “Will the PGA Tour fold up and go away? No. But they have some serious issues.”

Woods, 33, has been that most valuable of sports figures, an athlete who has drawn millions of casual fans to the sport and is recognized as a symbol of excellence even among non-golf fans. He became the first athlete to post career earnings of more than $1 billion earlier this year, with most of that money coming from endorsements that include a $30 million annual deal with Nike as the front man for its line of golf clothes and equipment.

Woods’ break from the PGA Tour is likely to have a devastating effect on TV ratings for golf, which is a staple of sports programming for the big broadcast networks.

When Woods suffered a season-ending knee injury in mid-2008 and took an eight-month break for surgery, many events on the PGA Tour saw catastrophic ratings declines.