Chinese insurance giant Anbang, virtually unknown abroad before buying New York's historic Waldorf Astoria hotel, is bidding nearly $20 billion to become an international hotelier -- raising questions over why it wants to enter the hospitality business, and over its murky shareholding structure.

Anbang is on a shopping spree with a near-$13 billion offer for Starwood Hotels & Resorts Worldwide -- owner of the Sheraton and Westin brands -- and a $6.5 billion purchase of 16 luxury hotel properties from hedge fund Blackstone.

They are the latest in a string of overseas acquisitions of various types that have helped Anbang -- established just 12 years ago -- grow from a domestic seller of property insurance into a financial services powerhouse.

"We must win the first battle and every battle thereafter as we are representing Chinese enterprises going global," Anbang chairman Wu Xiaohui told a recruiting event at Harvard University earlier this year.

"We must have conviction that we can profit even under the worst-case scenario, in order to move forward on each investment."

Anbang describes itself as one of China's biggest insurance companies with assets of 1.65 trillion yuan ($254 billion), more than 3,000 branches in China and over 30,000 employees globally. Its businesses range from insurance to asset management and banking.

But its ownership is unclear. Anbang has no publicly listed units and does not name its shareholders on its website.

Chinese media reports say they include both private and state-owned firms, including Shanghai-based auto giant SAIC -- a reflection of Anbang's early business in car insurance.

Chairman Wu is reportedly married to a granddaughter of late Chinese leader Deng Xiaoping. And the Southern Weekend newspaper has said some of the private shareholders are companies owned by Chen Xiaolu, son of Chinese Communist general Chen Yi who was later foreign minister.

The younger Chen denied the report but confirmed he was a business partner of Anbang's chairman in comments to business magazine Caixin.

- Sensational acquisitions -

Chairman Wu has driven through several overseas acquisitions, part of a government-supported drive for cashed-up Chinese companies to look abroad for new sources of growth as the economy slows at home.

Wu previously worked in auto sales and infrastructure investment before setting up Anbang, according to Chinese media reports.

Analysts say his company has been more aggressive than some of China's more traditional insurers in raising money from Chinese retail investors through wealth management products -- which offer higher returns than bank deposits but are riskier.

In November Anbang bought US insurer Fidelity & Guaranty Life for $1.6 billion, after snapping up Korean insurer Tong Yang Life for around $950 million and Dutch insurer Vivat for about $167 million earlier in the year.

In 2014 it bought two Dutch companies, insurer Fidea and Delta Lloyd Bank, according to its website.

The offer for Starwood, though, may not succeed, as it pits Anbang against US hotel giant Marriott International, which has already agreed a takeover of its rival.

Analysts said Anbang's journey into the hotel sector was probably driven by a desire to seek out more reliable investments, as well as to build its brand overseas.

"Anbang's strategy is to seek better targets with more stable returns on investment," Eva Liu, an analyst at Shanghai-based consultancy Z-Ben Advisors, told AFP. "But there are certainly risks to its high-profile and sensational acquisitions."

Chinese companies have recently grabbed headlines with multi-billion dollar buys.

State-owned China National Chemical Corp. (ChemChina) last month offered $43 billion for Swiss pesticide and seed giant Syngenta, which will be the biggest-ever overseas acquisition by a Chinese firm if it goes through.

China's Haier Group aims to buy the home appliances business of General Electric for $5.4 billion, while property developer Wanda Group has acquired Hollywood studio Legendary Entertainment for $3.5 billion.

bxs/slb/sm

THE BLACKSTONE GROUP

STARWOOD HOTELS & RESORTS WORLDWIDE

MARRIOTT INTERNATIONAL

SYNGENTA

DELTA LLOYD

Haier Group

GENERAL ELECTRIC

SAIC - SCIENCE APPLICATIONS INTERNATIONAL CORPORATION