Two unrelated lawsuits filed this week could bring an end to Warner Bros.’ upcoming Watchmen film, as well as to the two planned Hobbit movies from New Line Cinema.

The J.J.R. Tolkien estate is suing New Line Cinema, stating that the studio failed to pay part of the profits from its hugely succesfully Lord of the Rings film trilogy, while Fox is suing Warner Bros. over the rights to the Watchmen movie, based on the graphic novel by Alan Moore and Dave Gibbons.

In a press release from The Tolkien Trust, a British charity organization set up by the Tolkien estate, the trustees and HarperCollins Publishers are seeking over $150 million in compensatory damages, as well as punitive damages, and a court declaration giving the plainiffs the right to terminate any rights New Line may have to the Tolkien works, including studio’s planned two-movie The Hobbit adaptation.

LOTR director Peter Jackson had already signed on to executive produce The Hobbit films (see Peter Jackson to Produce Two ‘Hobbit’ Films), while it’s been reported that Hellboy director Guillermo del Toro is in talks to helm the films (see Guillermo del Toro to Direct “˜The Hobbit’), which would see 2010 and 2011 releases.

In an unrelated lawsuit, Fox is suing Warner Bros., claiming that Fox actually holds the exclusive copyrights and contract rights to develop, produce, and distribute a Watchmen film, according to THR. Fox seeks unspecified damages and to prevent Warner Bros. from going forward with their Zack Snyder-directed big-screen adaptation, which stars Malin Akerman, Billy Crudup, Matthew Goode, Jackie Earle Haley, Jeffrey Dean Morgan, and Patrick Wilson and is which is scheduled for theatrical release on March 6, 2009.