Danish Oil and Natural Gas company DONG is not giving up though. Officials said talks were under way to find a new financial partner to back its offer.
Vattenfall, seeking 67 percent of Elsam, and DONG are both state owned.
They see power generator Elsam as a key element in a consolidating Nordic power market and a buttress against growing competition, such as that from Germany’s E.ON.
The fight has also drawn in national governments, with Sweden strongly backing Vattenfall and Denmark irritated at its neighbour’s involvement.