BEIJING/SHANGHAI, Nov 23 (Reuters) - China's Zhongzhi Enterprise Group told investors it is heavily insolvent with liabilities of up to $64 billion, more than double its assets, as one of the country's leading wealth managers grapples with a deepening property sector crisis.

The firm, which has sizable exposure to China's real estate sector, apologised to its investors in a letter that said it had total liabilities of about 420 billion yuan ($58 billion) to 460 billion yuan ($64 billion).

The liabilities compared to Beijing-based Zhongzhi's estimated total assets of about 200 billion yuan, according to the letter, which was issued on Wednesday and was seen by Reuters. Zhongzhi did not immediately respond to a Reuters request for comment.

The worsening woes at Zhongzhi, a major player in China's $3 trillion shadow banking sector - roughly the size of the French economy - is set to reignite worries about the ripple effect of the property debt crisis on the broader financial sector.

Here are five facts about Zhongzhi:

* Starting off with timber and real estate trades in the 1990s, Zhongzhi quickly expanded into businesses ranging from chipmaking, healthcare, new energy vehicles and finance, according to its website. Its financial businesses include trust, asset management, insurance, futures, and wealth management.

* The group holds stakes in five asset management companies, four wealth management firms, and has a 33% stake in Zhongrong International Trust, a major trust company, which sold opaque trust products to individual as well as institutional investors promising as much as 6%-7% returns, compared to the benchmark one-year bank deposit rate of 1.5%.

* Xie Zhikun, the billionaire founder of Zhongzhi, died in December 2021 after suffering a heart attack in Beijing. Xie's wife is popular singer Mao Amin, and he is the brother of Xie Zhichun, former executive director of Central Huijin.

* Zhongzhi has been selling stakes in some listed companies it controlled over the past few years, and reducing the size of it business, after coming under pressure in the wake of China's crackdown on shadow banking, and the property market downturn.

* Still, Zhongrong has a comparatively high exposure to the real estate sector compared to its peers. Zhongrong Trust's real estate investment exposure accounted for 10.7% of its total assets under management as of the end of 2022, higher than the industry average of 5.8%, according to a report from Citigroup published in August.

($1 = 7.3074 Chinese yuan renminbi) (Reporting by Ziyi Tang and Ryan Woo in Beijing, Shanghai Newsroom; Editing by Sumeet Chatterjee, Kim Coghill and Muralikumar Anantharaman)