Exelon dropped its $7.5bn hostile bid for NRG Energy on Tuesday after the rival US power producer’s shareholders voted to install its own nominees to its board of directors rather than candidates proposed by Exelon.

Exelon took its fight to NRG shareholders after NRG’s board rejected its takeover offers repeatedly and refused to negotiate unless Exelon raised its bid substantially. Exelon had nominated up to nine candidates to NRG’s board and proposed to increase the board’s size.