NEW YORK — Michael Mann and Leonardo DiCaprio’s plan to collaborate on a movie about billionaire Howard Hughes has taken a turn toward New Line.

Led by production prexy Michael De Luca, New Line has embraced the Hughes picture and will continue developing the John Logan script as a starring vehicle for DiCaprio, who will play Hughes when he was a dashing, womanizing aviator. The hope is that Mann will direct the pic; he set up the project at Disney last summer under the overall deal he signed for his Forward Pass shingle (Daily Variety, June 24, 1999).

Since Mann just committed to direct Will Smith in a Muhammad Ali biopic at Columbia, and because there are no pay-or-play deals with either Mann or DiCaprio, the Howard Hughes pic is a down-the-road development pact. Though Mann received an Oscar director nom for his latest Disney financed pic, “The Insider,” the exit of Joe Roth from Disney and that studio’s heightened scrutiny of big-budget fare has led to speculation that other Mann projects could relocate.

Such talk is denied by sources close to the director, who has several promising Disney-based projects, including a film about the drug trade by “Armageddon” scribe Shane Salerno; another DiCaprio collaboration in “The Inside Man,” a Mann script about the true story of police union corruption that Harry Ufland is producing with Mann; and a Julius Caesar epic that Mann is contemplating with Tom Hanks that’s to be written by John Orloff.

For New Line, deal is a coup as it puts the studio in position for an event film with major elements.

“It is Howard Hughes’ formative years while he was setting air-speed records and charging through Hollywood,” said De Luca, who called Mann “the quintessential actor’s director who has proven time and again that his gift for dramatic storytelling is rivaled by none.”

Mann and DiCaprio have wanted to work together since they tried to mount a James Dean biopic, well before DiCaprio became a superstar in “Titanic.”

Theirs is just one of several attempts to make a movie based on the life of Hughes. While New Regency, which once figured to partner with Disney in the Mann-DiCaprio pic, has toyed with pairing Edward Norton and Milos Forman in a Hughes pic and Warren Beatty has long wanted to do one, it appears now that New Line has a clear track. New Regency may re-emerge as a possible financing partner when the film actually happens.

The other active Hughes project is a Mutual Film plan to produce a film based on “The Hoax,” Clifford Irving’s book about how he sold a phony Hughes autobiography to McGraw-Hill and did time for it after Hughes alerted the publisher that he hadn’t written a word of it.

New Line biz affairs exec veep David Alper negotiated for the studio while Mann was repped by CAA and attorney Harold Brown.