Hassan Bubacar Jallow, chief prosecutor at the U.N. International Criminal Tribunal for Rwanda announced that Ngirabatware was sentenced to prison, with credit for time served in pre-trial detention. Ngirabatware was arrested in 2007.
"The delivery of judgment today in this case marks a historic occasion and important mile stone in the work of the International Criminal Tribunal for Rwanda," Jallow said in a statement. "For today the tribunal has completed the trial phase of its mandate."
A 19-page indictment from the ICTR lists six charges, including genocide and the direct incitement to commit genocide. Among others, he was accused of working with other Rwandan leaders to "kill or cause serious bodily or mental harm to members of the Tutsi population" with the intent to destroy the ethnic community.
The ICTR, working from neighboring Tanzania, has acquitted eight and convicted 38 people who faced charges related to genocide. Some cases were referred to Rwandan courts.
"Some important work still remains to be done at the ICTR," the chief prosecutor stated. "Mainly in the management of the remaining appeal cases as well as management of legacy and closure related issues."
Conflicts between the Hutu and Tutsi ethnic communities left about 800,000 people dead in a 100-day massacre in 1994.