The Landmark chain includes eight movie theaters in Seattle: the Egyptian, Harvard Exit, Guild 45th, Metro Cinemas, Neptune, Seven Gables, Varsity and Crest Cinema Center.
Landmark's sale price was not disclosed. It will remain based in Los Angeles, under current management.
The theater chain has been for sale since 2001, after its parent company, Dallas-based Silver Cinemas International, filed for Chapter 11 bankruptcy protection. The troubled chain was later part of an $80 million sale to Toronto-based Onex, the parent company of Loews Cineplex. The deal fell apart when antitrust concerns made the merger doubtful.
As the nation's largest art-house chain, Landmark features first-run independent and foreign films, restored classics and nontraditional films in 54 theaters with 185 screens in 14 states, the company said.
Todd Wagner, Cuban's partner, said the purchase of Landmark by their Dallas company, 2929 Entertainment, is an essential element to complete their holdings in movie production, television syndication rights and HDNet, a high-definition national television network.
With the theater chain, Wagner said they can now take movies from production to the screen with no outside interference.
Wagner said 2929 would try to revamp and upgrade some of the theaters initially and then may install digital projection systems as the digital market develops.
Cuban and Wagner made their mark in Dallas as co-founders of Broadcast.com, one of the biggest success stories of the dot-com boom. Yahoo! bought the Dallas startup in 1999 for $5.7 billion.
Information from Seattle Times news services is included in this report.