The bidding war for Starwood Hotels & Resorts Worldwide between Marriott and China's Anbang Insurance Group is heating up. Starwood said Monday that Anbang has raised its offer to almost 14 billion U.S. dollars, or 82.75 U.S. dollars per share. That's higher than Marriott's 78 U.S. dollars per share announced last week.

Analysts say that if Anbang completes the deal, it would be the largest ever acquisition by a Chinese company in the United States. But Starwood said that its board hasn't yet changed its recommendation to its shareholders to support Marriott's takeover of the company.

Starwood says that's because Marriott has the financial capacity and wherewithal to increase its bid. A vote by Starwood shareholders on the Marriott deal is slated for April 8th.