Centrica said its adjusted earnings were down 14% to £507million impacted by “extreme warm weather” in North America as well as the impact of low commodity prices on exploration and production.
The company said central power generation also had an impact but it was partially offset by cost efficiency.
Adjust operating cash flow was up 19% to £1,372million, including working capital delivery in UK business.
Centrica said exploration and production free cash flow was positive in the first half of this year with capex and cost production costs down.
Iain Conn, Centrica chief executive, said: “The first half of the year has been demanding for Centrica, but the response has been strong and I am encouraged by the progress we have made. We are delivering underlying performance improvement and are building a robust platform for customer-focused growth.
“I remain confident in our ability to deliver both attractive returns and underlying cash flow growth, as we continue to implement our strategy.”