Ramush Haradinaj, Kosovo's former prime minister, has been cleared of charges of "ethnic cleansing" of minority Serbs during fighting in Kosovo in 1998.
Prosecutors had sought a prison sentence of 25 years against Haradinaj, who had commanded Kosovo Albanian forces in the west of the country against Serb security forces.
The verdict was met by loud cheers and applause from the public gallery.
The trial, at the International Criminal Tribunal for the former Yugoslavia (ICTY) in The Hague, had been marked by a reluctance of witnesses to testify.
One of Haradinaj's co-accused, Idriz Balaj, was also acquitted, while a third defendant, Lahi Brahimaj, who headed a detention camp, received a six-year prison sentence.
The prosecution had asked for 25 years for the three former
senior figures in the separatist ethnic Albanian Kosovo Liberation
Army (KLA), saying they had tried to evict Serbs and political
rivals from territories they controlled.
Haradinaj, 39, was the highest-ranking Kosovo Albanian politician to go on trial at the ICTY.
Dutch judge Alphons Orie, the president of the court, noted that
there had been great difficulties in persuading witnesses to give
Several witnesses refused to take the stand and were charged
with contempt of court.
According to the prosecution, important witnesses were intimidated to persuade them not to give evidence.
Shefquet Kabashi, a former KLA member, told the judges he refused to testify because other witnesses were being killed in Kosovo.
Judges told him he could get protection from the court, but Kabashi said that the protective measures "do not exist in real life, but only in the courtroom".
Haradinaj was a commander of the KLA at the time of the alleged atrocities, as was Balaj, 36, who allegedly headed a paramilitary unit known as the Black Eagles.
Brahimaj, 38, was a deputy commander of the KLA and ran the Jablanica prison camp, where he was said to have personally tortured inmates.
The accused had all pleaded not guilty.
Haradinaj founded the Alliance for the Future of Kosovo party shortly after a Nato bombing campaign ended a Serbian army crackdown on the ethnic Albanian majority in Kosovo.
The KLA, which fought against Serbian forces during the war, was
In 2005, after he was indicted by the ICTY, Haradinaj stepped
down as prime minister of the UN-administered Serbian province and
surrendered to the UN court.
Haradinaj's defence downplayed his role in the KLA, saying it
was not really an army but "a movement of terrified Albanian
civilians that grew out of village and family groupings".
His alleged position of leadership was in reality no comparison
to that of a conventional army commander, his lawyers told the
Kosovo unilaterally declared independence from Serbia in February, in a move recognised so far by more than 35 countries.