Barry Diller's People Inc. has offered to buy casino giant MGM Resorts for $48.30 per share in cash.
MGM is the company behind major Las Vegas properties including Bellagio and Aria.
Shares of MGM closed up roughly 15% Monday. Shares of Diller's firm closed up 1%.
Diller already sits on the board of MGM Resorts and would recuse himself from board actions on the proposed deal, he said in a letter to the MGM board of directors.
People Inc., formerly known as IAC, owns a roughly 26.1% stake in MGM.
"We began investing in MGM nearly six years ago because we believed it represented a rare kind of business: one with real world assets that AI cannot easily replicate or disintermediate and exceptional digital growth opportunities," Diller, chairman of People, said in a news release.
"We continue to believe the market materially undervalues the power and durability of MGM's assets," he said. "We believe MGM's management team is superb, and that there is a compelling opportunity to support MGM's next phase of growth and help unlock its full value."
CNBC's Andrew Ross Sorkin previously reported an offer could come as early as Monday.