But he borrowed heavily from loan sharks, and started to run into repayment difficulties this year, according to a friend of Mr. Wei's and people in Baotou's real-estate industry.

WSJ: Chinese Developers Face Pinch

The chairman of what domestic real-estate agents said was the biggest developer in the northern Chinese city of Baotou, he struck it rich in 1996 by helping rebuild the city following an earthquake.

WSJ: Chinese Developers Face Pinch

Chen Ningning built an early fortune in the steel business but now most of her fortune lies in publicly traded Inner Mongolia Baotou Steel Rare-Earth Group, where she is an investor (not an executive).

FORBES: How China's Self-Made Women Billionaires Earned Their Fortunes