Alcoa agrees not to idle Italy plants for 6 months

* Alcoa to keep Portovesme, Fusina plants open for 6 mths

* Alcoa, govt, unions to meet again in April

MILAN, Feb 26 (Reuters) - U.S. aluminium producer Alcoa Inc  has agreed to keep its Italian plants working for six months, instead of idling them as planned after the EU ordered it to repay state aid.

Italy's government said the agreement on the plants, which employ about 2,000 people, had been struck after talks with Alcoa and unions late on Thursday.

In November, Alcoa said it would temporarily idle operations at its 194,000-tonne-per-year smelters at Portovesme in Sardinia and Fusina near Venice after the European Commission ordered it to pay back most of the state aid it had received in Italy since 2006.

A statement from the Prime Minister's office said the agreement was made possible by a decree that lowers electricity tariffs for heavy corporate energy users.

"Within six months, following the European Commission's decision on the decree and an evaluation by the company, Alcoa will make checks that will take into account the evolution of the market," the statement said.

Alcoa, the government and other parties involved will meet again in April, it said.

The European Union's executive body ruled that Alcoa must repay state power subsidies previously agreed to by the Italian government and the U.S. aluminium producer.

Alcoa argues that a $300 million penalty imposed by the Commission, currently under appeal, would have a "devastating impact", given the dramatic decline in aluminium prices amid the global recession.

Aluminium prices slid more than 60 percent from record highs reached in July 2008 to the 7-1/2-year low hit a year ago.

(Reporting by Danilo Masoni, editing by Will Waterman)