Ugo Cappellacci told Italian radio that besides expressions of interest for the plant from Swiss companies Glencore (GLEN.L) and Klesch, there were two other interested parties, one of which was an Italian energy company.

"The other is a Chinese group that I know has already asked for access to the data room, though it is a first-contact stage and confidential, and so they have not yet given the identity of the group -- except to say it's big," he said.

An unsourced report in Italian daily MF said the Chinese company involved was Hong Kong Wan Hao International Trading.

Alcoa, the largest U.S. aluminum producer, has decided to close down its smelter in Sardinia where high power prices have undermined the competitiveness of the plant.

On Wednesday a Sardinian official said commodities trader Glencore was expected to present a letter of intent to buy Alcoa's Italian plant in 10-15 days.

Glencore's interest is conditional on the government being able to guarantee the continuance of steeply discounted power prices at the plant.

Asked if Europe might block such a discounted price scheme, Cappellacci said he had spoken to EU Commission vice-president Antonio Tajani.

"We have reason to believe a yes will arrive," he said.

(Reporting By Francesca Piscioneri and Giselda Vagnoni; Writing by Philip Pullella and Stephen Jewkes; Editing by Hans-Juergen Peters)

• A Permanent Economic Emergency