Greenpeace said Monday it has been barred from bidding for the German coal operations of Swedish energy giant Vattenfall, which the environmental activists intended to shut down.

"Greenpeace has been excluded from bidding process for Vattenfall's eastern German lignite (brown coal) division," the group said in a statement.

Citigroup, which had been in charge of the sale, had informed Greenpeace of its decision on Friday, arguing that the environmental protection group had no intention of standing as a bidder.

Neither Citigroup nor Vattenfall were willing to comment.

"We treat all potential bidders equally," said a Vattenfall spokesman.

Vattenfall is hoping to find a buyer for the open-cast coal mines and two power plants close to the German-Polish border amid growing resistance to fossil fuels in Germany, while public subsidies of renewable sources of energy makes coal-fired energy less profitable.

Greenpeace offered no money to purchase the activities, arguing that the lignite mines and power plants in eastern Germany were in fact a liability.

Greenpeace hoped to transfer the operations into a charitable foundation, paid for by Vattenfall and the German and Swedish governments, in order to phase them out by 2030.

Greenpeace director Annika Jakobson dismissed Citigroup's objections.

"Of course, we wanted to take part as a bidder. Our model was a realistic way of avoiding further ecological damage and social hardship."

She accused Vattenfall and the Swedish government of wanting to shirk their responsibility and of only seeking to obtain the highest possible price from the sale.

Two other bidders reportedly in the running are the Czech energy groups CEZ and EPH.