Energy giant SSE insisted it was battling "difficult" energy market conditions as it revealed a £115.4 million loss in its retail supply business just weeks after announcing a hike in household bills.
The group, which has more than nine million customers and is the UK's second largest generator of electricity , blamed the performance on rising costs of wholesale energy, environmental and social policies and distribution.
Its overall underlying group profits fell 11.7% to £354 million in the six months to September 30, but SSE delivered a 3.2% increase in its interim dividend payment to investors and pledged to hand out above inflation increases in its full year dividend, claiming this was vital to ensure the group is able to raise enough money to fund spending on its network.
SSE was the first of the major suppliers to announce a tariff rise, saying last month that it would lift prices by an average of 8.2% from Friday.
The first half loss in its retail supply arm compares with a £48.3 million operating profit a year earlier.
It comes as SSE - which trades as Southern Electric, Swalec and Scottish Hydro - also revealed falling electricity and gas consumption in the half year, down 3% and 1.7% respectively on average with weather effects stripped out.
Lord Smith of Kelvin, chairman of SSE, said: "Energy market conditions generally have been difficult for some time."
The group sought to deflect criticism over its move to pay shareholder dividends while raising prices for consumers.
Will Morris, group managing director of SSE's retail business, said: " Some politicians and media commentators have claimed recently that we value our shareholders more than our customers.
"Or to put it another way, we're focussed on paying them a dividend on their shares, regardless of what that means for our customers.
"Nothing could be further from the truth."
He added: "Without the investment made by shareholders, we couldn't afford to build the infrastructure or buy the equipment needed to deliver what customers need."