by Dan JohnsonJim Rasmussen apologized May 21 for illegally wagering on football, but said his decision to step down as Prairie Meadows chairman of the board was a combination of the betting controversy and ill health.Rasmussen, who admitted that he and his sons placed bets with accused bookmaker Robert Derryberry, resigned from the Iowa racetrack's board of directors May 9. He also turned in his license as a horse owner May 20, though the stable will continue to race under the name of his wife, Sandra."I've admitted that I gambled on football, and that was a mistake," Rasmussen said. "I'm sorry about that. I hope I didn't embarrass anybody over it."Rasmussen said his decision to step down as the track's chairman was accelerated by his health. Rasmussen, 66, said he would resume chemotherapy to treat the lung cancer he was diagnosed with in January 2000.Rasmussen is on a list of 55 prosecution witnesses to testify in the bookmaking trial of Derryberry. He faces no criminal charges, but his being on the list led to an Iowa Racing and Gaming Commission investigation and ultimately his withdrawal as a Prairie Meadows board member and a horse owner.Rasmussen said he and his sons bet on football for "a couple of years." As for the amounts, he said: "I'm not the biggest gambler on that list by any means."Rasmussen was appointed to the racing association when Prairie Meadows came out of bankruptcy in 1993, and became chairman in 1995. He is credited with solving many of the crises at Prairie Meadows over the years."It has been a part of my life for 10 or 11 years," Rasmussen said. "Like anything else that you've been involved with to that extent, there's a feeling that it's hard to believe that it's going to be over. I think it would have been the same had I resigned six months ago. It's a sad day when you leave something you've worked hard at."Rasmussen was a subject of controversy, mostly because his stable was very successful at Prairie Meadows. The Rasmussens have been among the leading Iowa breeders and owners since the mid-1990s, and are off to one of their best starts this year, having won the May 17 John Wayne Stakes at Prairie Meadows with Take Me Up.