BEING JULIA

[] (Three stars)

An actress’ showcase. Running time: 105 minutes. Rated R (some sexuality). At the Paris and the Union Square.

‘BEING Julia” is a pleasantly diverting period romp that Annette Bening turns into a wickedly funny tour de force.

The supremely talented Ben ing (“American Beauty”), who graces the big screen all too infrequently these days, pulls out all the stops playing a limelight-loving stage diva in 1930s London, and her vivacious performance should guarantee her a spot on Oscar’s list of Best Actress nominees.

“Julia” boasts an impressive supporting cast and a fine pedigree – it’s directed by Istvan Szabo (“Mephisto,” “Sunshine”) with a screenplay adapted by Ronald Harwood (“The Pianist”) from W. Somerset Maugham’s 1937 novella, “Theatre.”

But, as the title suggests, this movie is all about Bening’s Julia Lambert – a fabulous, mercurial character who is alternatively tough, vulnerable, gloriously sexy and nakedly lonely.

She’s a self-indulgent, flamboyantly theatrical star who never stops acting, even when alone with her theater impresario husband, Michael (Jeremy Irons), with whom she shares an affectionate but stale marriage.

Julia is having a midlife crisis, but perks up privately and professionally when Michael introduces her to a young American admirer, Tom Fennel (Shaun Evans).

Giddy with lust, Julia is blind to the deceptions playing out around her – until the movie’s juicy third act, in which she exacts a venomous, inspired revenge that warrants a standing ovation.

Evans is miscast, too bland to believably captivate the larger-than-life Julia.

But he’s the only false note in a cast that includes the wonderful Juliet Stevenson as Julia’s longtime assistant, Bruce Greenwood as her dependable confidant, and Michael Gambon, who, in an effective piece of magic realism, appears sporadically as the ghost of Julia’s first acting coach.