Warner Bros. and director Peter Jackson are seeking to turn the planned two-film Hobbit franchise into a trilogy, according to a report by the Los Angeles Times.

The Burbank film studio originally planned to release two Hobbit movies based on J.R.R. Tolkien’s literary prelude to The Lord of the Rings trilogy, and principal photography on those two pictures finished in New Zealand this month. The first is set to come out in December, followed by the second in December 2013. The two films combined cost about $500 million.

But Jackson has concluded that there is enough material from the book, as well as the extensive appendixes to The Lord of the Rings, to make a third film. New Line Cinema, the Warner Bros. unit overseeing production of the movies, is eager to see it happen, and talks are underway with actors and others who would need to sign off on the plan.

A third film is far from a certainty, however, because there are numerous rights-holders and actors with whom new deals must be made. Lead actors in particular hold leverage as they know New Line would need them for the picture. (Actors and some rights-holders had previously made commitments only to two pictures.) Talks with a number of the franchise’s actors — including Martin Freeman and Ian McKellen — have been taking place in the last few weeks.

Due to the complicated rights history of The Hobbit, a number of stakeholders must agree to the plan for a third picture.

Independent studio Metro-Goldwyn-Mayer controls 50 percent of the film rights and international distribution, though it has contracted with Warner Bros. to handle those duties on the first two movies. Producer Saul Zaentz has a long-running participation claim, as do Harvey and Bob Weinstein. The independent film moguls originally developed the Lord of the Rings movies when they ran Miramax Films.

The Tolkien estate receives a share of the earnings from the movies but does not need to grant permission for additional productions.