CBS wants to cut National Amusement's voting power through a special dividend to shareholders. Its board scheduled a meeting to consider the dividend for later on Thursday and confirmed that meeting would take place as planned despite the ruling.

National Amusements is controlled by the Redstone family, which has been trying to merge CBS and Viacom , both of which fall under its umbrella. But CBS and Viacom have not been able to come to terms on some aspects of the merger, and CBS was fighting what it called interference by the Redstones.

Chancellor Andre Bouchard's ruling would allow Shari Redstone and National Amusements to block that dividend, which would have cut their voting power.

"We are pleased by the court's decision to deny CBS and its special committee's unprecedented motion to try to deprive a shareholder of its fundamental voting rights," National Amusements said in a statement on Thursday.

CBS said in its own statement that the judge recognized its right to bring further legal action. "Today's ruling does not alter in any way the unyielding commitment of CBS and its Board of Directors to continue to act in and to protect the best interests of all CBS shareholders," CBS said in a statement.

"The judge today found that the allegations in our lawsuit 'are sufficient to state a colorable claim for breach of fiduciary duty against Ms. Redstone and NAI as CBS's controlling stockholder,'" the statement said.

The matter could wind up back in court, depending on the outcome of CBS' board meeting on Thursday, an analyst at Cowen and Co. noted. Redstone and her father Sumner Redstone have been trying to merge CBS with Viacom amid shifting sands in the media and entertainment industries.

The two sides had agreed to a price for a merger, CNBC reported earlier this week, but had not agreed on the leadership of the combined company. CBS went to court this week to block what it called interference by the Redstones, seeking a restraining order. National Amusements has said it doesn't intend to force a merger that isn't supported by both companies.

"The Redstones haven't (in the judge's view) done anything truly damaging to shareholders yet, so the judge is denying the restraining order," Cowen's Doug Creutz wrote in a research note to clients on Thursday. "But if they do something that appears truly damaging, the judge may well intervene."