The Commission said that the probes would focus on the "possible exclusion of potential competitors from the market", in a statement on 11 May.
In RWE's case, the Commission will investigate whether the group may have prevented rivals from acquiring customers by raising their costs and hindering their access to critical gas transport infrastructure.
As for Eni, the Commission said that it suspected the company of "capacity-hoarding and strategic under-investment in the transmission system, leading to the foreclosure of competitors and harm for competition and customers in one or more supply markets in Italy".
Both cases are being launched based on evidence gathered during raids last year, which also covered other large energy groups including Eon of Germany, Gaz de France, Distrigas and Fluxys of Belgium and Austria's OMV.
These other companies could also become the subject of formal probes in the coming months, as the Commission steps up the pressure to liberalise the energy market after a sector review carried out last year revealed "serious competition problems" were affecting consumers (EurActiv 11/01/07).
If the investigations confirm the accusations, the two companies could face financial penalties of up to 10% of their annual turnover.
