Intertainer, an on-demand broadband services provider, said Tuesday it has filed an antitrust lawsuit against Sony Corp. and two other firms for allegedly conspiring to fix prices relating to entertainment content distribution.

The California-based company has accused Sony, AOL Time Warner and Vivendi Universal of trying to control the marketplace for entertainment content on demand, hindering Intertainer's video-on-demand services and competition within the industry.

The three firms, which control 56 percent of the motion picture market and 63 percent of the music market, have conspired to fix prices in the video-on-demand sector by conducting "less than arms length" transactions with Movielink, a separate video-on-demand service they partly own, Intertainer said.

Intertainer accused the three firms of delaying negotiations, leaving it without access to the films it needs to provide its services.

The delay was designed to help Movielink monopolize the market, Intertainer said in the lawsuit, which was filed with a federal district court in California.

Sony collected information on Intertainer's proprietary technology and business plans, using its position as one of Intertainer's investors and board observers, Intertainer said.

Sony also persuaded former Intertainer employees to violate confidential knowledge relating to proprietary technology to help build Movielink, Intertainer said.

"The actions taken by these three leading studios will, in effect, eliminate consumer choices, produce higher prices, reduce output and lower quality services that would prevail in a competitive market," said Jonathan Taplin, chief executive officer of Intertainer.

An official of Sony Corp. of America categorically denied that the company had been involved in price-fixing activities.