Abdul Alim, of the Bangladesh National Party, was convicted on nine charges. Last week the tribunal sentenced another senior BNP figure, Salahuddin Quader Chowdhury, to death for crimes against humanity.
Alim was spared the death penalty because of his poor health. Prosecutors say he headed part of a militia fighting on the side of the Pakistan government that was trying to stop Bangladesh, then East Pakistan, breaking away.
Six current and former leaders of the main Islamic party, Jamaat-e-Islami, have been convicted by the same tribunal. Critics say the trials failed to meet international standards, and dozens of people have died in violent protests against the verdicts.
(See also my blog of July 19.)