RPT-UPDATE 2-Enel nears $21 billion asset sale to E.ON

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By Sonya Dowsett and Jo Winterbottom

MADRID/MILAN, March 27 (Reuters) - Enel (ENEI.MI: Quote, Profile, Research) looks set to clinch a $21 billion asset sale to Germany's E.ON (EONG.DE: Quote, Profile, Research) after all sides agreed the valuation, marking the final chapter in the world's biggest utility takeover and slashing debt for Italy's leading power generator.

The assets up for sale from Enel's Spanish unit Endesa SA (ELE.MC: Quote, Profile, Research) were valued at 11.5 billion euros ($18.15 billion), Endesa said, while the value of Enel assets up for sale was 2.025 billion euros, Enel said separately on Thursday.

The valuation was agreed among Enel, Spanish construction to energy company Acciona SA (ANA.MC: Quote, Profile, Research) and power group E.ON AG.

E.ON said its supervisory board would meet on Friday to decide whether to go ahead with the purchase -- jumping the gun by far on a 10-day deadline for it outlined in the statements.

Enel, Europe's fourth-biggest power company by market value, bought Endesa with Acciona for 42.5 billion euros in 2007, snatching it from under E.ON's nose after the German company faced obstacles from Spanish regulators.

Enel and Acciona then agreed to sell assets in Spain, Italy and France to E.ON that were valued at the time at 10 billion euros. The new valuations by investment banks were revealed earlier on Thursday.

The portfolio for sale includes Endesa's European assets situated in Italy, France, Poland and Turkey, plus the firm's subsidiaries in France and Italy, including debt.