Renewable energy firm Ecotricity has submitted three offers to acquire Chippenham-based rival Good Energy.
Stroud-based Ecotricity Group, led and founded by eco-entrepreneur Dale Vince, already owns a 25.1 percent stake in its rival.
It said the third indicative offer was made on 2 July, and was rejected by the Good Energy board on 8 July.
The offer, at 340p per share, represented a premium of 18.9 percent to the closing price of 286p per Good Energy share on 1 July.
Will Whitehorn, chairman of Good Energy, said: “Good Energy and its subsidiary Zap-Map have an extremely healthy, independent future focused on the best interests of our customers, employees and shareholders.
"We are committed to delivering growth for the exclusive benefit of our shareholders, not Ecotricity’s.”
Good Energy is a listed renewable electricity company. It was founded by Juliet Davenport in 1999. She stepped down as CEO in February, with Nigel Pocklington – former chief commercial officer of Moneysupermarket Group – taking the reins in May.
Back in 2017 Dale Vince tried to secure a seat on the Good Energy board after buying shares over a 12-month period to become its biggest single shareholder with a 25.3 percent stake.
A shareholders' meeting was arranged before Mr Vince withdrew his request.