By Alberto Sisto

ROME (Reuters) - Hundreds of workers from aluminum-maker Alcoa's Sardinian smelter clashed with police on Monday to protest against the factory's closure as the Italian government sought to avert the loss of more jobs.

Swiss industrial group Klesch offered a possible lifeline by expressing interest in the plant, but Alcoa in an email later said it had "not received any expressions of interest that are viable or different to those previously considered".

Baton-wielding police beat back workers trying to break through their lines outside the industry ministry in Rome, where government officials, labor unions and Alcoa executives met in a last-ditch effort to head off the shuttering of the unprofitable factory.

About 600 workers whose jobs are threatened beat their hard hats on the gates, set off large firecrackers, and threw missiles at police. Riot police pushed them back when they tried to storm the ministry's main gate, causing some minor injuries.

The factory supports about 1,500 jobs in Sardinia, and its closure would be a heavy blow for the Mediterranean island which is already beset by a 15 percent unemployment rate, well above the national average.

"The country's industrial policies have been abandoned for 20 years," Raffaele Bonanni, secretary general of Italy's second-biggest union, said outside the ministry. "Alcoa is like many other examples throughout the country."

Italy's industry ministry said in a statement after the meeting that Alcoa had agreed to slow down the planned closure and that the ministry would be summoning companies that have expressed interest in the plant for talks.

At the end of July, the industry ministry was mediating in 131 other disputes between companies seeking to cut jobs and unions trying to preserve them, according to a ministry document obtained by Reuters. With more than 163,000 jobs at stake, Rome is likely to see more protests in coming months.

Alcoa said in its email it would go ahead with the gradual shut down of the pots used to make aluminum, which began on September 1.

"We will continue the curtailment process and remain open to discuss the sale of a curtailed plant," Alcoa said.

(Reporting by Antonio Denti and Tony Gentile in Rome, and Martin de Sa'Pinto in Zurich; Writing by Steve Scherer; Editing by Michael Roddy)