Armstrong, a cancer survivor, announced he would step down on Wednesday, in what appears to be a move designed to limit the damage on the charity from the U.S. Anti-Doping Agency's (USADA) report.

The Lance Armstrong Foundation, also known as Livestrong, has raised some $500 million (380.8 million Euros) to support cancer patients, since it was established in 1997.

"To spare the foundation any negative effects as a result of controversy surrounding my cycling career, I will conclude my chairmanship," Armstrong said in a statement.

Armstrong, 41, said he intends to remain on the charity's board, and his announcement came as the organization prepared to celebrate its 15th anniversary this weekend.

It is the latest development in Armstrong's well-documented fall from grace. Last week's USADA report included testimony from 11 former teammates, and accused Armstrong of running the "most sophisticated" doping program in the sport's history. It said it had collected evidence to prove the seven-time Tour de France winner had engaged in the biggest doping conspiracy to date.

The USADA ordered that 14 years of Armstrong's career results be wiped out, as well as his Tour de France titles.

Armstrong strongly denies doping.

Sponsor drops Armstrong

Nike, one of Armstrong's main corporate sponsors, also said it was terminating its relationship with the cyclist and accused him of deception on Wednesday.

"Due to the seemingly insurmountable evidence that Lance Armstrong participated in doping and misled Nike for more than a decade, it is with great sadness that we have terminated our contract with him," the sporting goods giant said in a brief statement.

Australian cycling coach sacked

It was also announced on Wednesday that Australian Matt White, a former Olympian cyclist named in the USADA's dossier against Armstrong, was sacked from Cycling Australia as elite men's road coordinator.

38-year-old White rode on Armstrong's US Postal Service cycling team from 2001 to 2003, and admitted on the weekend to drug use and being part of a doping strategy while on the team.

Cycling Australia, the sport's governing body in the country, praised White's contribution to the sport but said his admissions put him in breach of its anti-doping policy and code of conduct.

jr/sej (AP, Reuters, dpa, AFP)