LOS ANGELES: Author Tess Gerritsen has sued Warner Bros. claiming the studio owes her millions in profits from the Oscar-winning hit film Gravity.

But the studio is pointing to her own statements downplaying similarities between the blockbuster and one of her novels.

Gerritsen sued Warner Bros. Entertainment Inc. in a Los Angeles federal court on Tuesday, alleging the studio violated an agreement she had with one of its subsidiaries to turn her novel Gravity into a movie. Gerritsen, whose books include a series that is basis for the TNT show "Rizzoli & Isles," sold the film rights to the Gravity novel for $1 million in 1999.

Warner Bros. declined comment on the case, but spokesman Paul McGuire noted that in October Gerritsen told an audience at an Indiana public library that the film wasn't based on her book.

" 'Yea, Gravity is a great film, but it's not based on my book," the Greencastle Banner-Graphic newspaper quoted Gerritsen as telling the audience. The paper noted the author said she had seen the movie, which starred Sandra Bullock, before her appearance.

Gerritson's lawsuit states she believes Gravity director Alfonso Cuaron was attached to adapt the book into a screenplay without her knowledge years before the movie was actually made. The author sold the rights to her novel to a production company that was bought by Warner Bros. in 2008.

The novel and film have some similarities, but their stories aren't identical.

The novel features a female medical doctor trapped in space after an organism infects her fellow astronauts and kills them. Her husband, who is on Earth, fights efforts to leave his wife in space to die alone.

Gerritsen's lawsuit states the author added elements such as the destruction of the International Space Station by space debris — a key moment in the film — to a screenplay she wrote to try to get her book on the big screen.

Gravity the film does not feature any outbreak of an organism, and Bullock's character is cut off from communication with Earth and does not receive any aid from people on the ground.

The lawsuit is not alleging any copyright infringement — a claim that would prompt a judge to compare the story lines — but rather alleges Warner Bros. has breached Gerritsen's contract for the film rights and profits.

Gravity won seven Academy Awards in March, but its screenplay was not nominated for an award.