HANOI, May 14 (Reuters) - Vietnam's highest-ranking official jailed in decades lost his bid on Monday to set aside a 13-year sentence for financial irregularities when he was chairman of state energy firm Petrovietnam, his lawyer said.
A court in the communist-ruled country upheld the sentence for former Politburo member Dinh La Thang, 57, who was arrested and tried in a crackdown on graft, mismanagement and nepotism that felled many high-profile officials.
The Hanoi People's High Court rejected an appeal by Thang against a January trial verdict that held him guilty of "economic mismanagement" at a coal-fired power plant overseen by PetroVietnam.
"I am very disappointed with the result of the trial because they didn't look carefully into all the details I presented," the lawyer, Dao Huu Dang, told Reuters by telephone.
State media this month blamed losses of 120 billion dong ($5.3 million) on Thang, saying he illegally assigned an incompetent subsidiary of the company to build the plant, instead of finding a competent contractor by a tender process.
In a separate case in March, Thang received an 18-year jail term on the same charges of "deliberate violation of state regulations on economic management".
At that trial, Thang was prosecuted over losses of up to 800 billion dong, or $35 million, in a PetroVietnam investment in Ocean Commercial Joint Stock Bank, forcibly taken over in 2015 by the State Bank of Vietnam after it suffered heavy losses.
Thang will also appeal against the 18-year term, his lawyer said. If that term is also upheld, the sentences will run successively for a total of 31 years in prison.
Another PetroVietnam official, Trinh Xuan Thanh, withdrew an appeal against the life sentence he received in the same case at the January trial, his lawyer said.
Last week, the Communist Party of Vietnam said that Thanh, whom Germany has said was kidnapped from Berlin in scenes reminiscent of the Cold War, withdrew his appeal because of "health conditions".
His lawyer, Nguyen Van Quynh, said Thanh did not have any health issues ahead of the appeal trial.
($1=22,768 dong) (Reporting by Khanh Vu Editing by James Pearson and Clarence Fernandez)