WASHINGTON — The new leader at USA Track and Field sent a letter to President Bush asking him to deny Marion Jones' request to commute her six-month prison sentence for lying to federal agents about her use of performance-enhancing drugs and a check-fraud scam.

"As the new CEO of USA Track & Field, I have a moral and practical duty to make the case against her request," Doug Logan wrote in an open letter to the president, delivered Tuesday.

Jones was sentenced in January to six months in prison and 400 hours of community service in each of the two years following her release.

After repeatedly denying that she used performance-enhancing drugs, Jones admitted last October she had lied to federal investigators in November 2003. Jones also admitted lying about her knowledge of the involvement of Tim Montgomery, the father of her older son and a former 100-meter world-record holder, in a scheme to cash millions of dollars worth of stolen or forged checks.

She was sentenced to six months on the steroids case and two months on the check-fraud case, but is serving those sentences concurrently.

"With her cheating and lying, Marion Jones did everything she could to violate the principles of track and field and Olympic competition," Logan wrote. "When she came under scrutiny for doping, she taunted any who doubted her purity, talent and work ethic. Just as she had succeeded in duping us with her performances, she duped many people into giving her the benefit of the doubt."

Jones is on the list of the hundreds of convicted felons who have applied for presidential pardons or sentence commutations. A pardon is an official act of forgiveness that removes civil liabilities stemming from a criminal conviction, while a commutation reduces or eliminates a person's sentence.

Logan, who took over as CEO at USATF last week, called Jones' downfall a sad spectacle, but one that needed to happen to help fix the problems track and field has endured because of doping.

"To reduce Ms. Jones' sentence or pardon her would send a horrible message to young people who idolized her, reinforcing the notion that you can cheat and be entitled to get away with it," Logan wrote. "A pardon would also send the wrong message to the international community."