Asked about concerns over whether the transaction - which would see DEA go to Russian billionaire Mikhail Fridman - might collapse, Guenther said that any M&A deal could theoretically fall apart as long as it was not closed.

RWE earlier on Tuesday said the sale of DEA may take longer than expected, adding to uncertainty over the fate of the 5.1 billion euro deal.

(Reporting by Christoph Steitz; Editing by Maria Sheahan)