A UN court on Thursday cut an ex-Bosnian Serb general's sentence by four years after finding there was no evidence he ordered certain shootings of civilians during a siege of Sarajevo.

The ruling reduced his sentence from 33 years to 29.

"The appeals chamber... reduces (Dragomir) Milosevic's sentence to 29 years of imprisonment," judge Fausto Pocar of the International Criminal Tribunal for the former Yugoslavia said in The Hague.

Milosevic, 67, had appealed his 2007 conviction, seeking an acquittal, while the prosecution had asked the appeals court to change the sentence to one of life imprisonment.

The judges found that while the trial court had erred in finding that Milosevic planned and ordered three incidents of shelling in 1994 and 1995, he nevertheless remained responsible for the crimes as a military commander.

Milosevic -- no relation to the late Yugoslav president Slobodan Milosevic -- commanded troops of the Bosnian Serb Army's Sarajevo Romanija Corps (SRK), who lay siege to the Bosnian capital Sarajevo from August 1994 to the end of the Bosnian war in November 1995.

The troops shelled the city and directed sniper fire against civilians as they queued for bread, went to markets or walked with their children.

According to human rights organisations, some 10,000 civilians, including 1,500 children, died in the 44-month siege of Sarajevo -- the longest such blockade in Europe since the end of World War II.

Milosevic surrendered to the ICTY in December 2004, six years after he was first indicted. Three years later, he was convicted of war crimes and crimes against humanity, specifically murder, inhumane acts and terror.

His appeal was heard in July this year.

The appeals judges found no proof of Milosevic having planned and ordered the sniping of civilians.

The evidence, they said, did not allow for the inference "that Milosevic ordered all sniping incidents attributed to the SRK snipers."

He was nevertheless responsible as a commander for having failed to prevent and punish such crimes committed by his subordinates.

The judges said there was also no evidence that Milosevic had ordered the shelling of three specific civilian sites: the Bascarsija Flea Market in December 1994, the BITAS building on August 22, 1995, and the Markale Market six days later in which mortar fire killed 34 people and wounded 78.

Milosevic was being treated in a Belgrade hospital during the commission of the last two crimes.

These findings, however, do not "diminish his active and central role in the commission of the crimes," said the judges.

"Indeed, Milosevic did more than merely tolerate the crimes as a commander.

"In maintaining and intensifying the campaign directed at the civilian population in Sarajevo... he provided additional encouragement to his subordinates to commit the crimes against the civilians."

The reversal of some of the convictions did "have an impact, although limited, on Milosevic's overall culpability," said Pocar.

"Although these findings do not change the fact that the entire population of Sarajevo was the victim of the crime of terror committed under Milosevic's command, they do involve fewer victims of the crimes of murder and other inhumane acts imputable to Milosevic."

The court dismissed the prosecution's appeal in its entirety.

Milosevic's predecessor as SRK commander, Stanislav Galic, is the only war crimes criminal to have received a definitive life sentence, on appeal, from the ICTY.

He was also convicted for the Sarajevo siege.