The former head of CNPC, China's top energy group, admitted his guilt and asked for leniency at the opening of his trial on charges of bribery and abuse of power, the latest in a string of top officials caught in an anti-graft campaign.
Scores of senior figures in the ruling Communist Party, the military and state-owned enterprises have been felled in President Xi Jinping's two-year war on corruption.
State television showed pictures of a grim-faced Jiang Jiemin, who also ran the state asset regulator for five months before being sacked in September 2013, standing in the dock with two policemen at his side.
He was formally charged in March.
Jiang was a close associate of Zhou Yongkang, the once-powerful domestic security chief and member of the elite Politburo Standing Committee, the most senior person to have been charged with corruption.
Zhou had also been at CNPC, the parent company of PetroChina Co. Ltd., having risen through the ranks to serve as general manager from 1996 to 1998.
"The facts of my crimes are clear, the evidence is true and conclusive," Jiang said, according to a statement by the Hanjiang Intermediate People's Court in the central province of Hubei, which is trying him. "I admit my crimes and am penitent."
Jiang did not defend himself when the evidence was presented, the court said.
He needs to be held accountable under the law for his crimes, which include "bribery, not being able to account for a large number of assets and abuse of power by a staff member at a state-owned company," the court cited the prosecutor as saying.
Jiang is willing to serve his time, and "earnestly requested leniency," the court added, saying the verdict would come at a later, unspecified date.
State news agency Xinhua said that the trial of a second former senior energy executive, Tao Yuchun, once general manager of CNPC's Kunlun Natural Gas Utilisation Company, opened in the southern city of Zhuhai on the same day.
He is accused of embezzlement, bribery and other financial crimes worth more than 300 million yuan ($48 million), the report said.
Xi's graft crackdown has taken down at least a dozen former associates and protégées of Zhou.
Zhou was a patron of former high-flying politician Bo Xilai, jailed for life in 2013 for corruption and abuse of power in the worst political scandal in decades.
Arrested last year and expelled from the party, Zhou will be tried in Tianjin, a city near Beijing, but a date has not been set.
