IN 1972, Sergio Leone – the Italian filmmaker noted for cooking up spaghetti westerns – turned down an offer to direct “The Godfather” because he had his own idea for a gangster yarn.

It would take a decade of toil and tens of millions of dollars for Leone to make his dream mob movie, “Once Upon a Time in America” (1984). But what happened next turned out to be a director’s nightmare.

His 227-minute epic about Lower East Side Jewish gangsters from 1921 through the late ’60s – featuring Robert De Niro, James Woods, Tuesday Weld, Elizabeth McGovern, Joe Pesci, Treat Williams and Jennifer Connelly – debuted at Cannes, winning praise from critics and audiences.

But the producer, the Ladd Co., had other ideas. Without asking Leone’s opinion, the pea-brained bean counters sliced the movie to 139 minutes and changed its structure before releasing it in the United States.

While Leone’s version audaciously jumped backward and forward in time, the recut edition told the story in (yawn!) chronological order.

Leone was devastated. He died in 1989 at the age of 67, never having made another movie.

Wherever he is now, the Rome-born auteur – whose movies almost always took place in America – would be happy to know that his complete version is part of a five-flick Leone retro running Friday through May 22 at BAM Rose Cinemas.

Also on the sked are “Once Upon a Time in the West” (1965), with Henry Fonda, Claudia Cardinale and Charles Bronson, plus three with Clint Eastwood: “A Fistful of Dollars” (1964), “For Few Dollars More” (1965) and “The Good, the Bad and the Ugly” (1966).

BAM Rose Cinemas is on Lafayette Avenue, off Flatbush Avenue, in Brooklyn; bam.org.

* If you’re looking for great performances by women you need look no further than Isild Le Besco in “A Tout de Suite” and Connie Nielsen in “Brothers.”

Le Besco plays a hot-to-trot teen who runs off with her bank-robbing boyfriend in Benoit Jacquot’s black-and-white homage to the French New Wave.

As usual, the pouty actress is quite at ease with full-frontal nudity – but she can act, too.

Nielsen keeps her clothes on in Susanne Bier’s “Brothers,” the Danish-born actress’ first movie in her native land.

Until now, she’s been seen in American movies like “Gladiator” and the dark French thriller “Demonlover.”

“Brothers,” in which she plays a woman torn between two siblings, one of them her husband, just could be her finest work yet.

V.A. Musetto is film editor of The Post. He can be e-mailed at vam@nypost.com