Relatives of victims of asbestos-related diseases were torn Monday between joy at a guilty verdict against a Swiss billionaire and a Belgian baron and anger at the length of their sentences.

"They don't deserve to live because they knew" that the asbestos their company used in its products could kill, said Libero Tomasoli, 77, who suffers from the lung disease asbestosis.

Silence reigned in the Italian court as a judge found guilty in absentia Stephan Schmidheiny, the former owner of a company making Eternit fibre cement, and major shareholder Jean-Louis Marie Ghislain de Cartier de Marchienne.

They were sentenced to 16 years for causing an environmental disaster and failing to follow safety regulations in the trial over 3,000 alleged asbestos-related deaths in Italy's industrial heartland.

Several hundred relatives draped in Italian flags bearing the words "Eternit Justice" broke down and sobbed as the verdict was read out. Others hugged each other, clapped and cheered as the groundbreaking two-year trial came to an end.

"It's a great satisfaction, a historic decision... which I hope will resonate around the world," said 57-year-old Piera Barbonaglia, whose husband died 10 years ago from a tumour.

The trial, which began in 2009 after a five-year investigation, was thebiggest of its kind against a multinational for asbestos-related deaths.

Schmidheiny and De Cartier were ordered to pay 30,000 euros ($39,000) in damages to relatives of people killed and 35,000 euros for every sick person, as well as other payouts expected to total tens of millions of euros.

Schmidheiny is 64 years old and De Cartier is now 90. Their crimes usually carry a maximum 12-year sentence, but prosecutors had sought 20 years for each because they say the fall-out continues to affect victims.

Defence lawyers had denied the accused had direct responsibility for the Italian company, and the pair were absent from court throughout. The lawyers said they would appeal, meaning the case could drag out for several more years.

Aurelio Lussu, 44, whose uncle died from an asbestos-related disease, agreed that the trial was "historic," but he said he had expected the pair to have received "a lot longer" in prison -- "at least 20 years."

His friend Luca Cavallero, 38, said the verdict was "ridiculous."

"They killed people and they get 16 years? They are the root of the tragedy and they put our future in peril because we are still up to our knees" in a drama which is continues to kill people all around the region, he said.

Eternit went bankrupt six years before asbestos was banned in Italy in 1992.

Asbestos, which was banned in Europe in 2005, but is still widely used in the developing world, had been used mainly as building insulation for its sound absorption and resistance to fire, heat and electrical damage.

The inhalation of asbestos fibres can cause lung inflammation and cancer, and symptoms can take up to 20 years to manifest after exposure.

In France, the first complaints by workers exposed to asbestos date back to 1996 but there have been no major trials even though health authorities blame asbestos for between 10 and 20 percent of lung cancers.

Eric Jonckheere, a representative for Belgium victims whose father, mother and two siblings were killed by asbestos-related diseases, and who had attended the hearing, said: "It just goes to show, David can win against Goliath!"