LOS ANGELES — Floyd Landis will appeal his doping case to the Court of Arbitration for Sport, his last chance to retain his 2006 Tour de France title.

Emily Carhart, a spokeswoman for the law firm Gibson, Dunn & Crutcher, said Wednesday that Landis had decided to appeal.

An arbitration panel ruled against Landis last month, upholding the results of a test that showed the American cyclist used synthetic testosterone to fuel his spectacular comeback Tour victory. That decision meant Landis must forfeit his title and is subject to a two-year ban, retroactive to Jan. 30.

Landis repeatedly has denied using performance-enhancing drugs.

In a news release on the Floyd Fairness Fund Web site, Landis said, "Knowing that the accusations against me are simply wrong, and having risked all my energy and resources — including those of my family, friends and supporters — to show clearly that I won the 2006 Tour de France fair and square, I will continue to fight for what I know is right."

If Landis loses his appeal, he'll be the first person in the 105-year history of the Tour to lose the title because of a doping offense.

After the Sept. 20 ruling, Landis said he was unsure if he would appeal.

The arbitrators voted 2-1 again him. In their 84-page decision, the majority found the initial screening test to measure Landis' testosterone levels — the testosterone-to-epitestosterone test — was not done according to World Anti-Doping Agency rules.

But the more precise and expensive carbon-isotope ratio analysis, performed after a positive T-E test is recorded, was accurate, the arbitrators said, meaning "an anti-doping rule violation is established."

Landis' yellow jersey is scheduled to be awarded to second-place finisher Oscar Pereiro next week.

The Spanish cyclist will receive the winner's jersey in a ceremony Monday in Madrid, race organizers said Tuesday.

The International Cycling Union declared Pereiro the winner a day after the arbitrators' ruling.