The supplier maintained its full-year earnings per share and dividend guidance, however.

SSE, which has frozen household energy prices this winter, said it lost another 50,000 customer accounts in the three months to Dec. 31, leaving a total of 8.08 million, in line with customer losses seen earlier in the year.

SSE said renewable energy production was 5.1 terawatt-hours (TWh) in the quarter, down from 6.8 TWh the same time in 2015, while gas- and oil-fired generation nearly doubled to 12.8 TWh from 6.6 TWh in 2015.

Centrica's British Gas, SSE's largest rival, raised its full-year earnings outlook last month after its trading division benefited from large power price swings.

(Reporting by Karolin Schaps; Editing by Mark Potter)