Eldorado Resorts and billionaire Tilman Fertitta, the owner of the Golden Nugget casino and Houston Rockets basketball team, are both actively considering a bid for Caesars Entertainment, people familiar with the talks told CNBC.

Despite other published reports of Caesars' board being on the verge of approving a move to put the $24 billion company up for sale, a person close to the situation said, the board has made no decision, though it is open to the prospect of a sale if that's the most expeditious way to create value.

Both prospective buyers are performing due diligence, reviewing non-public information in Caesars' books and data room, the people said.

Billionaire activist investor Carl Icahn has increased his stake in Caesars and now owns more than 28%, including swaps, a person familiar with his investment said. In a deal with Caesars, Icahn added three new directors to the board. Those directors are getting up to speed, reviewing strategy and the company's standalone prospects, a person said.

Earlier this week, Jefferies gaming analyst David Katz cut the price target on Caesars by $1 to $10, citing poor weather in the first quarter combined with a challenging winter on the Las Vegas Strip. But Katz points out, "We remain confident in the long term earnings potential of the properties and the embedded advantages within the Caesars Rewards program as the leadership and ownership structure of the business are resolved."

Shares of Caesars are down 15 percent over the past year, but the stock has gained 36% since January, bringing its market value to $6.2 billion. On Thursday, shares were trading up nearly 3% at about $9.33.

By comparison, Eldorado has a market value of $3.7 billion. Its stock is up more than 33% since the start of the year.

Investors are expecting an announcement from Caesars within the next five days, as Icahn has placed an April 15 deadline for Caesars to either to hire a new CEO of whom he approves or to add another new Icahn appointee to the board.

CEO Mark Frissora's last day at Caesars is April 30.

News of Fertitta's recent interest was first reported by the New York Post. Reuters had previously reported Eldorado's interest.