UPDATE 1-Italian soldier killed in Afghanistan

(Adds details, name and age of dead soldier)

ROME, July 14 (Reuters) - An Italian soldier was killed and three others were wounded in Afghanistan on Tuesday when their convoy was hit by a roadside bomb, the Italian military said.

The bomb hit the first vehicle in a convoy 50 km (31 miles) north of the western town of Farah, killing Corporal Alessandro Di Lisio, 25.

Fourteen Italian soldiers have died in Afghanistan. The most recently deadly attack before Tuesday's was a firefight in February 2008 near Kabul.

Prime Minister Silvio Berlusconi expressed his condolences but stressed "the necessity and the importance of the peacekeeping mission in Afghanistan for the stability of a strategic region."

Italy has boosted its forces in Afghanistan by 500 troops, to more than 3,200, in preparation for next month's presidential election there. Italy is the sixth largest contributor to the NATO-led military operation in Afghanistan.

Parliament observed a moment of silence. The small Communist Party reiterated its call for the withdrawal of Italian troops.

The poll is regarded as crucial both for Kabul and Washington, which has identified Afghanistan and neighbouring Pakistan as its top foreign policy priority.

The Taliban have stepped up their attacks against foreign troops since the launch of a major offensive by U.S. marines, NATO and Afghan forces in Helmand province. July has been the bloodiest month for foreign troops in nearly a year. (Reporting by Massimiliano di Giorgio and Antonella Cinelli, editing by Mark Trevelyan)