SSE lost around 160,000 customers over the three months to the end of December, the company has reported in a third quarter trading update.

It finished 2018 with 5.88 million customer accounts in Great Britain compared to 6.45 million a year previously.

SSE said it is still considering options for the future of its retail arm – SSE Energy Services – after plans for a merger with Innogy’s Npower were scrapped in December. These options include a standalone demerger and listing on the stock exchange, a sale or an “alternative transaction”.

If none of these are viable it may be kept as a “separate, ring-fenced business” with the SSE group.

SSE said the suspension of capacity market payments in November will blow a £60 million hole in its revenues for the 2018/19 financial year. It has therefore lowered its forecast for adjusted earnings per share (excluding from SSE Energy Services) by 6p to between 64p and 69p.

The company also announced that the £200 million proceeds from the recently announced sale of stakes in the Stronelairg and Dunmaglass onshore windfarms will be used to fund a share buyback programme. The buyback is expected to commence before the completion of the transaction which is due by the end of March.

SSE chief executive Alistair Phillips-Davies said: “We continue to make good progress in our core businesses of regulated energy networks and renewable energy, complemented by flexible thermal generation and business energy sales.”

“We are also making progress in assessing the options for the future of the energy services business,” he added. “SSE has a clear strategy and good long-term prospects for its high-quality core businesses and assets that contribute to the transition to a low-carbon economy and will support the creation of value and delivery of our dividend plan in the years to come.”