The world's largest casino company, Harrah's Entertainment Inc. (HET), on Monday agreed to a buyout offer from two private equity groups valued at $16.7 billion, a source told the Associated Press.

The groups will pay $90 per share, said a person with knowledge of the negotiations.

The agreement with Apollo Management Group and Texas Pacific Group came late last week but lawyers for both sides have been working out the details, said the person, who spoke on condition of anonymity because of the sensitivity of the talks.

An official announcement on the deal could come as early as Tuesday, the person said Monday.

A Harrah's spokeman would not comment when contacted by FOXNews.com

Deliberations by a special committee of Harrah's board began after a deadline of Tuesday last week for offers. Penn National Gaming Inc. (PENN), a Wyomissing, Pa.-based race track and casino operator, was eliminated from the bidding with its reported bid for $87 per share bid, mostly in cash.

The decision ends more than two months of silence following the original offer by Apollo and Texas Pacific for $81 a share, announced Oct. 2.

Shares of Harrah's rose $3.30 $82.80 in afternoon trading on the New York Stock Exchange.

Private money has gone on a months-long shopping spree for casino operators, which are valued for their cash-generating ability and significant real estate holdings. The Harrah's deal marks the biggest deal to take a public casino company private and ranks as one of the largest leveraged buyouts in history.

Analysts have said the search for casino companies would continue.

Harrah's is the world's largest casino company by revenue, operating 39 casinos nationwide, including Caesars Palace, Bally's and Paris on the Las Vegas Strip, and Caesars and Harrah's in Atlantic City, N.J. It also has interests in Casino Windsor in Canada, to be renamed Caesars Windsor in early 2008, and Conrad Punta del Este in Uruguay.

By year's end, Harrah's is to acquire all the shares in U.K.-based London Clubs International PLC, which operates seven casinos in the U.K., two in Egypt, one in South Africa and is a consultant for a casino in Lebanon.

Harrah's also is pursuing projects in Singapore, the Bahamas, Spain and Slovenia.

The Associated Press contributed to this story.