Passengers walk past an advertisement for Anbang Insurance Group at a subway station in Shanghai, Oct 18, 2012. [Photo/IC]

"China is relaxing rules on insurance companies' investment, and Anbang is a market leader," Gui said.

The high-profile companies that Anbang has bought include the Waldorf Astoria Hotel in New York, US life insurance provider Fidelity and Guaranty Life, Belgium's Fidea Assurances and Delta Lloyd Bank, and Dutch insurance company VIVAT. Anbang has also taken a controlling stake in South Korea's Tong Yang Life.

All this investment "can help Anbang to set up a global insurance business network and stabilize returns", Gui said.

A report by real estate consultancy company JLL in October said that China's outbound real estate investment had surged by 50 percent to $15.6 billion a year to date, fueled by insurers' growing interest in boosting the allocation of their real estate assets.

Last week, Marriott increased its offer to $13.6 billion, topping an earlier one of $13.2 billion from Anbang. In a statement, Marriott said it was committed to completing its deal with Starwood but didn't increase its current offer.

Contact the reporters at caixiao@chinadaily.com.cn.