LOS ANGELES (AFP) - A spin-off movie of the Star Wars franchise about the early life of smuggler and crack pilot Han Solo has lost its two directors, the production company behind the project said on Tuesday.

Directors Phil Lord and Christopher Miller left due to creative differences, Lucasfilm president Kathleen Kennedy said.

Lord and Miller "are talented film-makers who have assembled an incredible cast and crew, but it's become clear that we had different creative visions on this film," she added.

In a statement, Lord and Miller also cited "creative differences".

"Unfortunately, our vision and process weren't aligned with our partner's," they said.

The announcement came as filming is under way at London's Pinewood Studios for the untitled movie, which is scheduled to come out several months ahead of Star Wars: Episode VIII in December 2018.

In the movie, Alden Ehrenreich stars as Solo, a role that made Harrison Ford a Hollywood superstar in the original 1977 movie and its sequels.