Former British cycling star Robert Millar revealed he has undergone a sex change and is now known as Philippa York.

The 58-year-old Scot -- who was a master climber crowned King of the Mountains in the 1984 Tour de France and finishing fourth overall -- wrote in cyclingnews.com she had been Philippa York for a while but had only announced the news now because 'times had moved on'.

"As much as I've guarded my privacy over the years there are a few, I believe obvious, reasons to why I haven’t had a public ‘image’ since I transitioned," York wrote.

"Gratifyingly, times have moved on from 10 years ago when my family, friends and I were subjected to the archaic views and prejudice that some people and sections of the tabloid media held.

"Thankfully gender issues are no longer a subject of such ignorance and intolerance, there's a much better acceptance and understanding."

York, who as Millar finished runner-up in the Vuelta twice and the Giro d'Italia once, said she had known from an early age she was different.

"I've known I was different since I was five years old, (but) what that difference was and how to deal with it has taken a fairly long time to come to terms with," wrote York.

"All I will say is it hasn't been an overnight process.

"There's no one story line that fits everyone. For me personally, until given the right information there wasn’t a feeling of being trapped, rather it was more a case of the life I was living wasn’t the one I felt I ought to be having."

York, who won three stages on the Tour de France, also expressed the hope she could pick up more media work -- she is presently commentating on the Tour for English broadcaster ITV.

"Hopefully my occasional writing will continue, a return to doing some media and more cycling-related things are a possibility," wrote York.

"I'll assess how the commentary with ITV4 goes and then take it from there but it would be good to expand my horizons."

York, who among her victories as a cyclist numbered the key Tour warm-up race the 1990 Dauphine-Libere, said sports in general still had a long way to go to join the modern world in its attitude to sexuality.

"It's been the case that anyone thought to be different has been singled out for ridicule or presented as some kind of danger and yet outside of sport that attitude isn't tolerated," she wrote.

"It's strange but at least nowadays the opportunity to be listened to and explain some of the issues encountered are available.

"Sport has generally lagged behind in its attitudes to anything other than the heterosexual norm, in that context cycling has been one of the sports most resistant to change.

"It'll catch up eventually."