Andreotti, 80, one of the West's towering postwar political figures, is still on trial in the Sicilian capital Palermo on Mafia association charges. The verdict in that case is due in late October or early November. Prosecutors are seeking a 15 year sentence.
The jury of two judges and six private citizens concluded after four days of deliberations that there was not enough evidence to convict the senator-for-life, who was indicted for premeditated murder along with five other people in the 1979 slaying of journalist Mino Pecorelli.
All the defendants were acquitted. Andreotti was not in court to hear the verdict.
His lawyer, Franco Coppi, quoted him as saying simply "Grazie," or "Thanks," after being informed of the jury's decision.
The prosecution alleged the Mafia killed Pecorelli at the behest of Andreotti, who feared embarrassing revelations. The accusation was based on the testimony of Mafia turncoat Tommaso Buscetta.
The other defendants included an ex-senator from Andreotti's now-defunct Christian Democrats, Claudio Vitalone, as well as two Mafia bosses and two alleged triggermen.
Andreotti said he was the victim of a vendetta by political enemies and mobsters.
Because the Palermo case is also largely based on turncoat testimony, the outcome of the Perugia trial was being closely watched as a possible clue to how the Sicilian trial might turn out.
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