Germany's two largest utilities, E.ON and RWE, are to receive an official warning from the German cartel office for attempting to pass on the costs of carbon emission certificates to customers.

Germany’s current attitude towards the regulation of its energy industry has recently been described as ‘Marxist’ by a high-ranking Gazprom official, and fresh moves from the cartel office are likely to reinforce that attitude in some.

The targets of the action, E.ON and RWE, have already taken steps to open up competition in the distribution arena in a bid to avoid regulatory sanctions, but they now appear to have come unstuck over their pricing policies.

According to a report from the German newspaper Handelsblatt, the German cartel office will tell the energy giants that their policies to link end-user price rises to the market value of carbon emissions certificates is anti-competitive and must stop.