Cycling-Tour de France may withdraw from 2016 UCI calendar

* Tour organisers threaten to take races off schedule * ASO concerned about clashes in major race dates By Julien Pretot PARIS, June 19 (Reuters) - Tour de France organisers ASO (Amaury Sport Organisation) have threatened to withdraw their races from the International Cycling Union calendar over a lack of progress in the UCI's reform programme, Reuters has learned. A source close to the UCI's management committee told Reuters that ASO had sent a letter saying they would withdraw from the 2016 calendar if the reforms do not go forward, with their main concerns centred on ensuring major race dates do not clash. There is no risk of the Tour and the ASO's other major races not taking place but they could do so outside the umbrella of cycling's governing body, leading to a potentially damaging split. The ASO, who own the Tour de France, the top-tier classics Paris-Roubaix and Liege-Bastogne-Liege and the one-week Paris-Nice and the Criterium du Dauphine, were not immediately available for comment. A split would mean the ASO could make their own team selection for their races. This year teams from the UCI World Tour get automatic spots for the Tour and other prestigious events. The ASO and UCI were also at odds between 2005 and 2008 when the Tour de France organisers refused, along with their counterparts at the Tour of Spain and Giro d'Italia, to be part of the UCI Pro-Tour that later became the World Tour. NO VALIDATION The calendar reform was voted in this week by the Professional Cycling Council (PCC) but did not get the UCI management committee's validation. The management committee has also been pushing for UCI president Brian Cookson to remove director general Martin Gibbs who has been heavily criticised, sources told Reuters. More than 30 UCI collaborators have been sacked or have left since Cookson took over from Pat McQuaid in 2013. ASO's threat gives Cookson a problem as the UCI could become a hollow shell without a hand in the top races. The Briton may therefore be pressured by his management committee to yield to the pressure from Tour organisers. The UCI is confident the reform will succeed. "We are hopeful of finalising soon our discussions with all stakeholders whether race organisers, teams, riders, around a project that will restore the credibility in our sport, promote the sport in both existing and new markets, make the cycling season understood and attractive to fans and recognise the UCI World Tour as part of a larger and interdependent system," the governing body said in a statement given to Reuters. (Editing by Pritha Sarkar)