Some investors and analysts, including Enkraft and Bernstein, have said that removing coal from RWE's portfolio would sharpen the group's profile as an energy player focused on renewables and help to revive its shares.
However, CEO Markus Krebber has repeatedly said a separation or sale of the assets - which are still profitable - would take too long, be too complex and not be in line with the group's responsibilities to the thousands of workers who mine lignite and operate plants.
The German government has in the past raised the possibility of creating a foundation with a view to ensuring they are phased out as smoothly as possible.
"We have ... made it clear that we are ready for talks on this. However, it is now up to politicians to put the issues on the agenda," Krebber told shareholders during the group's annual general meeting.
Krebber also said that any sale or separation of the assets could only happen with Berlin's consent, adding political support for such a move was "hardly to be expected".
Ingo Speich, at RWE shareholder Deka, said waiting for Berlin to make the first step was not a solution, and that the group should review the potential uplift to its valuation from separating the coal assets.
Enkraft, which holds around one million shares in RWE, said spinning off coal remained the group's biggest value creating measure by far, but "management continues to consistently ignore this issue".
