Nationals principal owner Ed Cohen (L) talks with GM Mike Rizzo (R) in Viera. Cohen is the Lerner family’s point person on the MASN dispute and was in a New York court on Monday. (Jonathan Newton/The Washington Post)

NEW YORK — A New York Supreme Court judge granted partial discovery Monday to Mid-Atlantic Sports Network, forcing Major League Baseball to hand over documents relating to the long-standing dispute over the Washington Nationals’ regional television rights fees. MASN, which is majority controlled by the Baltimore Orioles, had been seeking documents detailing incoming MLB commissioner Rob Manfred’s involvement with a arbitration panel that ruled this summer that MASN should pay the Nationals more in rights fees.

After three hours of arguments, Judge Lawrence Marks also approved MASN’s request that MLB turn over documents detailing the panel’s meetings, attendance and the details of the correspondence between Manfred and any MLB staff and the panel. MASN contends that Manfred, who has been serving as Commissioner Bud Selig’s right-hand man, and MLB had a vested interest in the panel’s ruling, which awarded the Nationals nearly $300 million in TV rights fees during the 2012-2016 “reset” period.

The small legal procedure marked another minor victory for MASN, which contends the process was also tainted because MLB gave the Nationals $25 million in a so-called secret deal and because MLB, the Nationals and the arbitrators all used the same law firm and didn’t disclose it.

“We’re grateful that the judge recognized that there is much to be discovered as to who did what and when they did it,” Orioles attorney Arnold Weiner said afterward. “This goes a long way in getting answers to the these questions.”

John Buckley, the attorney representing MLB, declined to comment after the hearing was over.

The hearing to decide whether to throw out the MLB panel’s TV rights award is slated for March 2.

There is no deadline for MLB to hand over the documents, but in previous court filings a two-week time-frame was suggested. The sides have a Jan. 8 conference and reply briefs are due four days later. Dec. 15 was originally supposed to be the main hearing date but the discovery squabbling led to delays. The Nationals and Proskauer Rose, the law firm in question, all handed over documents that MASN requested. MLB, however, refused without a court order.

Marks took issue with the $25 million loaned to the Nationals that was expected to be paid back with the new rights fees, saying that it showed MLB “clearly” had a vested interest in the panel’s ruling. Buckley said MLB was a multi-billion enterprise and $25 million was “not a material amount.” Marks responded: “Well, it’s not beans.”

Buckley said MASN’s document requests would be “very, very burdensome.” He added: “You can’t just fish around for information. That’s prohibited.”

The entire conflict between the Nationals and MASN has caused a headache for MLB, which didn’t want legal action on the matter because of the publicity. The league even facilitated negotiations to sell off MASN. The Nationals and MASN have been squabbling over TV rights fees since 2012, when the reset period first started.

Marks granted MASN a preliminary injunction against MLB and the Nationals on Aug. 18 and repeated Monday that he doesn’t want it to stay much longer, hoping for a timely resolution. But given the legal maneuvering, the issue is at least three months away from any more clarity.