Billionaire investor Kirk Kerkorian, who holds a 56% stake in MGM Mirage Inc., launched an overture for two of the big Las Vegas casino company’s prized assets in a volley that has put the entire company in play, the Wall Street Journal reports.

The proposal, announced on the eve of the company’s annual meeting today, caught MGM Mirage management off guard. The board “will begin its review of Tracinda Corp.’s filing and its implications for the company, and will respond in due course,” the company said in a statement. MGM Mirage said it is “mindful of its obligations, including to its shareholders, lenders, employees and the communities in which the company operates.”

Mr. Kerkorian’s move ostensibly puts all of the company’s assets, except the Bellagio Hotel and Casino and the CityCenter project, up for grabs. MGM Mirage owns a third or more of the Las Vegas Strip and about half of its hotel rooms. Analysts said the properties Mr. Kerkorian wants to acquire from MGM Mirage are the company jewels: the luxurious Bellagio and the nearby CityCenter, an ambitious $7.4 billion megaproject set to open in late 2009 that combines private residences, boutique hotels, a resort casino and a retail-and-entertainment district.

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