That has left many highly leveraged Chinese property companies reeling. Several developers, including China Properties Group and Fantasia Holdings Group, have defaulted on dollar debt in recent months, while others, such as Yango Group and Xinyuan Real Estate, have managed to stave off default by negotiating debt swaps. China Aoyuan said last week that its creditors have demanded that the company repay about $651 million in principal after recent credit rating downgrades.