Italy urges Alcoa to slow plant closures

Italy has called on US aluminium maker Alcoa to respect its commitment to slow down the planned closure of its Italian plant, after trade unions accused the company of going back on its word.

"In the face of worrying news from the plant, the government calls firmly on Alcoa to accurately respect commitments formally undertaken by the group's international managers," the industry ministry said in a statement on Wednesday.

The US company must make sure the closure "is carried out according to the procedures and gradual time frame established" at a meeting with the government in Rome on Monday aimed at mediating a heated dispute over the plant's future.

Two workers from the Italian plant climbed up the smelter's 70-metre water tower in protest after trade unions claimed Alcoa was going back on its word and carrying out the shutdown according to the old schedule.

"We've been taken for a ride," one of the protesters, Franco Bardi, was quoted as saying in the Corriere della Sera newspaper.

"The company has gone back on its word, it wants to shut down immediately, and it's unacceptable."

Three other workers had spent four days camped on the water tower last week.

Just two days ago it had appeared that the crisis at the plant had been averted by Alcoa's reported promise to the government to allow more time for possible buyers to come forward to save the 600 or so jobs at risk.

On Monday, hundreds of workers from the threatened plant clashed with police during a protest over the closure in Rome, but the government later said Alcoa had agreed to slow down that process.

Swiss industrial group Klesch or the commodities giant Glencore are rumoured to be interested in taking over the site.

The company, which posted a net loss of $US1.151 billion ($A1.11 billion) in 2009, has said it is shutting down the foundry in a way that will ensure it can be restarted should an offer be made soon.