A Singapore court for their part in the crime had already sentenced four other directors of the firm.
The Singapore-based firm, which has a monopoly on the Chinese jet fuel market, did so by wrongly betting against future movements in the price of oil, and then attempting to hide the losses from investors.
Mr Chen had originally been facing a total of 15 charges, but he admitted six as part of a plea bargain.
Mr Chen's former business colleagues Jia Changbin, Gu Yanfei and Li Yongji were all fined a total of 70,000 Singapore dollars earlier this month, after they pleaded guilty to charges of insider dealing and failing to disclose losses.
CAO's problems has become one of the biggest business scandals to rock Singapore ever since the collapse of Barings Bank in the 1990s.
Its losses were found out in November 2004 when the firm was forced to seek legal protection from creditors.
