Exclusive: “Rock of Ages” has started firming up its cast with “Dancing With the Stars” champ Julianne Hough in final negotiations to star opposite Tom Cruise in New Line’s adaptation of the Broadway musical.

Mary J. Blige is also set for the pic, to begin lensing May 19 in Florida.

“Hairspray” helmer Adam Shankman is directing and choreographing “Rock of Ages,” which is built around rock hits of the 1980s by Journey, Joan Jett, Bon Jovi and Pat Benatar. It focuses on a couple that meets at the Sunset Strip club Rock of Ages, falls in love and tries to stay together while living the rock life.

Shankman told Variety that Hough agreed to take the part Thursday after he phoned her while she was waiting for a plane.

“I asked her if she wanted to be in a movie with Tom Cruise and she wanted to not get on the plane so she could celebrate,” he said. “Her audition was surreal — maybe the best I’ve ever seen.”

The musical’s creator, Chris D’Arienzo, scripted the adaptation, and Shankman and Justin Theroux (“Tropic Thunder”) are polishing the script. Carl Levin, Matt Weaver, Scott Prisand, Tobey Maguire and Jennifer Gibgot will produce. Garrett Grant, Janet Billig and Hillary Weaver are exec producing.

The musical premiered in Los Angeles in 2006 and came to Broadway three years later, receiving five Tony nominations. The Sherrie character is a recent arrival from Kansas hoping to make it big in Hollywood. Hough’s first big-screen role came in “Burlesque.” She’s starring opposite Kenny Wormald in Paramount’s remake of “Footloose,” due out in October.

Hough’s repped by CAA.