Xiao Gang, the embattled head of China's securities regulator, has offered to resign, sources said, after perceived mismanagement wiped more than $5 trillion off the value of the Shanghai and Shenzhen stock markets since they peaked last June.

The 57-year-old chairman of the China Securities Regulatory Commission (CSRC) tendered his resignation last week after his brainchild, a "circuit breaker" mechanism to limit stock market losses, was blamed for exacerbating a sharp selloff, a source with ties to the leadership and a financial industry source said.

The circuit breaker was deactivated Jan. 7, just three days after its introduction.