A service that just targets the television market and uses proprietary technology and data is alleged to violate a contract.

Nielsen Holdings wants to prevent comScore from using its technology to compete in the business of TV ratings. On Friday, Nielsen filed a contract suit in New York federal court and is now seeking an injunction.

According to Nielsen, the two companies made a deal with each other in 2014 on the heels of Nielsen's acquisition of Arbitron. At the time, the Federal Trade Commission had just reviewed the merger and issued an order that was aimed at ensuring that other market participants could offer cross-platform services. To comply with the government's requirements, Nielsen entered into an agreement with comScore, which has been a leader in measuring online audience for various websites.

Nielsen says it granted comScore a right to use proprietary technology and data for an allegedly limited context — when online mixes with television. The plaintiff argues that comScore can't use the technology to compete with Nielsen for an "individual, stand-alone service." Thus, Nielsen alleges comScore is "precluded" from using what it gathered for linear television audience measurement.

"Nonetheless, in breach of the Agreement, comScore has announced plans to offer a service called 'Extended TV,' which will provide television audience measurement in the absence of online audience measurement for virtually all programming and the vast majority of networks," states the complaint. "Nothing in the Remedial Agreement or any other contract between the parties permits comScore to do that. Indeed, the Agreement explicitly bars comScore from using [Portable People Meter] data for 'individual, stand-alone services' like linear television measurement services."

Nielsen says that if comScore is not enjoined, it will suffer irreparable harm through the loss of important customers and decreased market share.

Nielsen has also filed an arbitration demand, but is nevertheless going to a New York federal court for pre-arbitral injunctive relief. The breach of contract claim is being handled by Aidan Synnott and Erin Morgan at Paul Weiss.

"We can confirm that there is a dispute regarding interpretation of the 2013 FTC consent decree, which resulted from Nielsen’s acquisition of Arbitron, that provides comScore with access to certain Nielsen data," says a comScore spokesperson in response to the lawsuit. "Due to the pending nature of these legal proceedings, we have no further comment at this time."