Viacom and CBS have been dancing around each other for years. Now their reunion might actually happen.
CBS offered to buy the cable TV and film company, according to a person familiar with the matter.
A deal would bring the two media companies back together more than a decade after they separated.
But it's not exactly a marriage of equals. At the time the bid was submitted, it valued Viacom at less than its market value, and CBS wants its CEO and chairman Les Moonves to lead the new company, the person said.
Viacom is best known for its cable channels, including MTV and Nickelodeon, and movie studio Paramount. CBS controls the CBS broadcast network, Showtime and streaming network CBS All Access.
The Redstone family, led by media mogul Sumner Redstone, controls roughly 80% of the voting shares of both companies. The Redstones have toyed with the idea of bringing their companies back together before. The last significant attempt failed in 2016.
The latest bid isn't exactly shocking, either.
"I think this merger is all about trying to keep up with Disney and the changing media landscape," said Jason Schloetzer, a Georgetown University business professor who studies corporate governance.
Big media mergers have grown more popular in recent years as internet and tech companies like Facebook, Amazon and Netflix upend the industry.
Disney, for example, said late last year that it would buy most of 21st Century Fox for about $52 billion. And AT&T and Time Warner - the parent company of Warner Bros., HBO and CNN -- are fighting the US government in court over their potential combination.
CBS and Viacom are in a unique position because of their history together, Schloetzer added.
The two companies used to be one until they broke apart in 2006.
Redstone split CBS and Viacom in part to allow Moonves and former Viacom executive Tom Freston to each become CEO of the respective companies, instead of choosing one of them to run the whole company. He fired Freston less than a year later.
At the time of the split, Viacom was widely expected to be the faster-growing company. CBS, led by Moonves, is now the stronger of the two businesses, bolstered in part by its strong programming lineup.
CBS has also carved out some success in streaming, a market that is dominated by relative newcomers like Netflix. Its two streaming services, CBS All Access and Showtime, have a combined 5 million subscribers.
Meanwhile, Viacom -- which owns the Paramount film studio in addition to its cable channels - has struggled.
Brian Wieser, an analyst with Pivotal Research, said Viacom's weaknesses aren't much of a surprise.
"They haven't really established many zeitgeist-changing programs or content," he said.
Wieser added that a CBS merger could inject some life into Viacom, though at the cost of heavy investment. He said the success of the deal might ultimately come down to how much incentive Moonves would have to turn Viacom around if he's put in charge.
"He's spent so long fine-tuning CBS into the machine that he wants it to be," Wieser said. Making Viacom a success, though, is a very different job.
Moonves has held several top-level executive positions within both CBS and Viacom since the 1990s, and he has run CBS during the entirety of its recent run as an independent company.
Viacom is now run by longtime company executive Bob Bakish, who has held the CEO title since 2016. His rise followed the high-profile exit of Viacom CEO Philippe Dauman, who was forced out that year by Sumner Redstone's daughter, Shari Redstone.
Sumner Redstone is in very poor health. He is 94 and can no longer speak, according to multiple media reports. In 2016, Redstone was the victor in a prolonged court battle, winning control over Viacom.
CBS stock closed Tuesday at $52.86, up about 4.2%. Viacom's stock, valued at $29.42 per share, was down more than 3%.
--CNNMoney's Brian Stelter and Brian Lowry contributed to this report.