(AGI) Turin, Sept 25 - The Ivrea prosecutor's office concludedits investigation on the deaths caused by asbestos exposure atthe Olivetti plants in the Canavese area. Thirty-nine formerexecutives have been investigated and accused of involuntarymanslaughter, including Carlo and Franco De Benedetti, RodolfoDe Benedetti and Corrado Passera. Roberto Colaninno has beenaccused of unintentional injuries. It was established that 13former workers died of mesothelioma contracted at the Olivettiplants in a 30 year period. . .