AceShowbiz - Actor Warren Beatty has slept with more than 12,000 women, according to a new authorized biography of the legendary Hollywood lothario. Beatty has enjoyed high profile romances with Madonna, Jane Fonda, Diane Keaton, Joan Collins, Julie Christie and his current wife Annette Bening - but writer Peter Biskind claims the 72 year old secretly seduced thousands of women during his heyday.

In "Star: How Warren Beatty Seduced America", Biskind estimates the actor has been with "12,775 women, give or take, a figure that does not include daytime quickies, drive-bys, casual gropings, stolen kisses and so on." Biskind, who wrote the biography after candid chats with the "The Story of Bonnie and Clyde" star, lifts the lid on his subject's many famous lovers, and his legendary stamina for sex.

The author claims older partner Joan Collins ditched Beatty because his insatiable appetite wore her out, and he only met his match when he met the much-younger Madonna on the set of 1990 movie "Dick Tracy". The pair dated, but the "Material Girls" close pal Sandra Bernhard reveals Beatty struggled to keep up with the party-loving pop star.

Bernhard tells Biskind, "We would taunt him, say things to make him feel uncomfortable. He was the perfect target, because he played the befuddled old man with her." Biskind adds, "Beatty, a man who was accustomed to being worshipped by women, was on dangerous ground with Madonna."