Nov. 4 (Bloomberg) -- Cinemark Holdings Inc., which operates movie theaters, sued Imax Corp., seeking a court declaration that it isn’t in violation of Imax patents for converting theaters to giant-screen theaters.

Cinemark said Imax, which sells projection and sound systems for giant-screen theaters, sent a letter Oct. 26 claiming it is violating two Imax patents. The suit was filed yesterday in U.S. District Court in Sherman, Texas.

The case is: Cinemark USA Inc. v. Imax Corp., No. 09-CV- 549, U.S. District Court Eastern District of Texas (Sherman).

To contact the reporters on this story: Bob Van Voris in New York at rvanvoris@bloomberg.net.

Last Updated: November 4, 2009 11:27 EST