SCOTTISHPOWER has said its customer numbers fell in the first quarter, as it prepared to increase prices for close to a million households.

The energy company's customer numbers fell from five million to 4.9 million at the end of the first quarter of 2018.

Its earnings rose 306 per cent in its home supply business to £165.8 million in the six months to the end of June 2018. ScottishPower said the division had "recovered" from a poor performance in 2017.

ScottishPower's average customer consumption increased by four per cent year-on-year over the period, which was mainly due to cold weather from the Beast from the East at the start of the year.

The figures come after the Big Six energy company, which is owned by Spanish multinational Iberdrola, increased prices in a move that hit 950,000 households.

The company increased its standard variable gas and electricity prices for around a third of its customers from June 1, with impacted households facing an average increase of 5.5 per cent.

ScottishPower attributed the rise to an increase in wholesale energy costs, alongside costs associated with upgrading meters and delivering electricity from low-carbon sources.

The firm has been investing in wind power, having completed a £650 million project to build eight wind farms in Scotland.

Over the first six months of 2018, Scottish Power also started construction on an offshore wind farm in East Anglia, the East Anglia ONE project.

Keith Anderson, ScottishPower's chief executive, said: "All of our business areas are performing in line with expectations.

"Our investment in onshore wind last year has seen an increase in electricity generated, and excellent progress has been made on delivering the £2.5 billion East Anglia ONE project. We expect first generation of electricity next year."