Last month, the state audit office revealed figures that put the amount of stolen cash at 33.9 billion yuan ($4.8bn), 10 times more than the original estimate of $480 million.
The state has already handed down tough convictions to up to 20 officials and businessmen involved in the theft of the pension funds, including one suspended death sentence and several life imprisonments.
Chen had been charged with abuse of power in connection with the pension fund scandal, as well as accepting 2.39 million yuan ($342,000), some of which was given to his wife and son, earlier press reports said.
Dereliction of duty
State press said that charges of dereliction of duty were dropped against him in Friday's decision.
During his one-day trial, Chen admitted he was "partially responsible" for the pilfering but did not plead guilty, according to previous state media reports.
Chen's case is the biggest corruption scandal to hit the Chinese government since Chen Xitong, a former Beijing mayor, was removed from his post in 1995 and sentenced to 16 years in jail.
Chen was charged with corruption in 2006 when he was a member of the ruling Communist Party politburo, a grouping of about 20 or so of China's most powerful politicians.