By Liana B. Baker and Jonathan Stempel

(Reuters) - The battle between satellite and broadcast TV for viewers headed to U.S. courts on Thursday when DISH Network sought to allow viewers to skip commercials at the touch of a button, something the four major broadcast networks are fighting tooth and nail.

Dish Network Corp asked a Manhattan federal judge to declare that its "Auto Hop" feature does not infringe any copyright owned by the four major U.S. television networks: Walt Disney Co's ABC, CBS Corp's CBS, News Corp's Fox and Comcast Corp's NBC.

Fox, meanwhile, filed its own lawsuit in a California federal court to stop Dish from transmitting its programs in a way that lets viewers watch them without commercial interruptions.

Dish introduced a high-definition DVR called the Hopper earlier this year. With 14 million subscribers, it is the second-largest satellite TV provider in the United States behind DirecTV.

TV networks are upset that Dish, led by billionaire chairman Charles Ergen, would introduce the "Auto Hop" feature that may well please viewers, but would undermine the networks' key source of revenue: advertising.

In its complaint, Dish maintained that the Auto Hop lets viewers fast-forward through but not delete commercials, and said the feature does not alter the broadcast signal.

Dish said a court order declaring the feature legal was needed given that the networks had begun considering lawsuits, have made "sharply critical" public comments about Auto Hop, and had begun rejecting Dish ads featuring the Hopper or Auto Hop.

Fox, in its lawsuit, countered that Dish has only "narrow permission" to retransmit its broadcast signals, and should not be allowed to sell a product that lets it trumpet "commercial-free TV" without permission. It also seeks compensatory and other damages for the alleged copyright infringement.

CBS declined to comment. ABC and NBCUniversal did not immediately respond to requests for comment.

The cases are Dish Network LLC v. American Broadcasting Cos et al, U.S. District Court, Southern District of New York, No. 12-04155; and Fox Broadcasting Co et al v. Dish Network LLC et al, U.S. District Court, Central District of California.

(Reporting By Liana B. Baker in New York and Jonathan Stempel in Toronto; Editing by Carol Bishopric and Leslie Gevirtz)