Grease launched 24-year-old Travolta on his "first" career

The new film is as yet unnamed and the script is in its early stages, but Conn said it would explore how the characters in Grease had evolved 20 years after graduating.

"Jim Jacobs, the author of the original Grease musical, said it was about firsts - first car, first kiss, first time getting pregnant - and the energy that accompanies firsts," Conn said.

"That's the Grease spirit, and that's what we're exploring 20 years later."

Channing was later Oscar-nominated for Six Degrees of Separation

Conn added that the audience would learn about the original characters through their children.

Apart from the confirmation of Conn in the Frenchy role, casting will not get under way until the script is finished, but the producers hope to offer roles to all original cast members.

Travolta played Danny Zuko, a leather-clad wild teenager who becomes smitten with Sandy Olsson (Newton-John), a beautiful but "square" student at Rydell High School.

Zuko is ridiculed by his friends over the relationship but, of course, love conquers all.

Drop-out Frenchy is inspired by Frankie Avalon in Grease

The original cast included 32-year-old Stockard Channing playing 17-year-old Rizzo, Jeff Conaway, Michael Tucci and Dinah Manoff.

For the new parts, Conn hopes to cast actors who have appeared in some version of Grease over the years.

Grease began as a Broadway musical and spawned a film, a hit soundtrack, a sequel - starring Michelle Pfeiffer - and a Broadway revival.

The movie became a huge box office hit, taking $340m (�234.9m) worldwide.

Several songs from the film - You're The One That I Want, Hopelessly Devoted to You, Summer Nights and Greased Lightnin', became chart hits.