The Yugoslav war crimes tribunal sentenced the former chief of the Yugoslav army to 27 years imprisonment Tuesday for providing crucial military aid to Bosnian Serb forces responsible for the Srebrenica massacre and for a deadly four-year campaign of shelling and sniping in Sarajevo.

The case against Gen. Momcilo Perisic was the first time the U.N. court convicted a civilian or military officer from Yugoslavia of war crimes in Bosnia, and underscored the Yugoslav army's far-reaching support for Serb rebels in both Bosnia and Croatia who committed the worst atrocities of the Balkan conflicts in the early 1990s.

The link between the disintegrating Yugoslav federation and Serb forces in the breakaway republics has been a matter of dispute and was the keystone of the trial in The Hague of Yugoslav President Slobodan Milosevic. But that trial ended without a conclusion when Milosevic died in his cell in 2006 of a heart attack.

The former Yugoslavia is now divided up into republics including Serbia, Bosnia and Croatia.

The U.N. judges convicted Perisic on charges of providing officers, troops, ammunition and logistical support to the rebel Serbs in Bosnia and Croatia, but acquitted him on charges that he was directly responsible as a superior officer to the Bosnian Serbs commanded by Gen. Ratko Mladic.

Presiding Judge Bakone Moloto said evidence reflected Perisic's "inability to impose binding orders on Gen. Mladic ... who maintained a measure of independence throughout the war."

Mladic was caught and transferred in May to The Hague for trial after 16 years as one of the tribunal's most wanted fugitives.

The court did, however, convict Perisic of having direct control over Croat rebels who shelled the capital, Zagreb, in May 1995, killing seven civilians and injuring dozens more.

But while the court ruled Perisic did not exercise superior responsibility over Bosnian Serbs, it said he oversaw a well-structured and covert operation to send military aid from Belgrade to the rebel Serbs, including millions of bullets and thousands of artillery shells.

Moloto said the military aid "became more centralized, structured and coordinated during Gen. Perisic's tenure."

In a majority ruling, the three-judge panel said Perisic's material support "had a substantial effect on the crimes" committed by Bosnian Serb forces, including the massacre in 2005 of 8,000 Muslim men in the U.N.-protected Srebrenica enclave, Europe's worst massacre since World War II.