On 8 July 2009, the Commission announced that E.ON and GDF Suez were each fined €553m for market sharing. The anticompetitive agreement in question dated back to 1975, when Ruhrgas A.G. (now part of the E.ON group) and Gaz de France (now part of the GDF Suez group) jointly built a pipeline transporting Russian Gas from the South Eastern part of Germany to its South Western borders. Both companies had agreed in a written document that they would not compete against each other on their respective market. While this agreement was acceptable when drafted in 1975, it became illegal under European law from 2000 when the 1998 Gas Market Liberalisation Directive came into force. Both companies have continuously denied continuation of the enforcement of the said agreement after 2000 but the Commission found that the arrangement was only abandoned in 2005.

The hefty fines imposed by the Commission are identical because it was considered that both companies were equally liable for the illicit scheme. It has been noted that it is one of the highest fines in total for a horizontal price-fixing / market-sharing case. GDF Suez announced in a press release dated 8 July that it would file an appeal against the Commission decision with the Court of First Instance.