Verizon had expressed interest in acquiring CBS before merger talks heated up with its corporate sibling Viacom, sources say.

CBS disclosed the interest of another would-be acquirer in court documents today. In the filing, the network claims Shari Redstone, who controls CBS through the family-owned National Amusements, had discouraged the potential bidder from making an offer.

Multiple sources say Verizon had been involved in high-level discussions with CBS about a year ago. It’s unclear how far these talks had progressed, with some characterizing the conversations as early stage.

Redstone indicated that she would see greater value in a Verizon bid for both CBS and Viacom — a position that some saw as chilling interest in a potential deal.

Neither CBS nor National Amusements would comment, and Verizon did not respond to multiple requests seeking comment.

The talks, however preliminary, provide a backdrop for the CBS-Viacom merger discussions.

National Amusements may view a combined media property, whose assets include a top broadcast network, a film studio and multiple cable outlets, as positioned to fetch a higher price from a potential acquirer.

Media analyst Barton Crockett spotted CBS’s disclosure of an outside party’s interest in its lawsuit seeking a temporary restraining offer to prevent Redstone from taking steps to replace directors or interfere with a board vote on a proposal that would reduce the family’s voting control over the network.

“We do believe that in a consolidating media industry the unique assets at both CBS and Viacom could drive meaningful premiums to their current trading values, especially if, as we expect, Time Warner/AT&T are successful in defeating the DOJ’s antitrust lawsuit to stop the merger,” Crockett wrote. “In that case, we could see more interest among pipes/platform companies in acquiring meaningful legacy brands.”