Caesars Entertainment and Eldorado Resorts are in preliminary talks about a merger, Reuters reports, citing people familiar with the matter.
Caesars is providing some limited confidential financial information to Eldorado, which is carrying out due diligence on the potential combination of the two companies, the report said.
Caesars and Eldorado have market capitalizations of $5.4 billion and $3.6 billion, respectively.
Activist investor Carl Icahn again raised his stake in Caesars Entertainment last week and is expected to push for a sale of the operator.
Icahn first disclosed he had built a stake in February and has further increased his holding to 17.5 percent. He also now controls three board seats, or 25 percent of the total.