Germany's Green Party has joined the conservative Christian Democrat parties in calling on the federal government to critically examine plans by utility group RWE to sell its oil and gas arm RWE-DEA to a group of Russian investors led by billionaire Michail Fridman.

In view of the Crimea crisis, why should a Russian millionaire buy the company and gain access to Germany's strategic oil and gas reserves, Green party leader Cem Özdemir commented to the newspaper Rheinische Post. This, he said "would make Germany even more dependent on Russian president Vladmir Putin."

Özdemir's remarks echoed those made days earlier by Norbert Röttgen, chair of the federal government's Committee on Foreign Affairs.

On Mar. 16, RWE said it had agreed to sell its subsidiary to the Luxembourg-based Russian consortium LetterOne, subject to regulatory approval. The investors - who edged out BASF subsidiary Wintershall and the Hungarian oil and gas group Mol, reportedly are prepared to pay €5.1 billion, including debt of €600 million.