Its adjusted operating profit fell 17% to £1.25 billion last year and the company lost around 1.4 million domestic customers in the UK.
Centrica said it expects the new programme “to involve reduction in like-for-like headcount of around 4,000 by 2020.”
However, around 1,000 additional roles are expected to be created during the same period across three of its departments.
Group Chief Executive Iain Conn described the company’s financial result in the second half of 2017 as “weak”, primarily reflecting poor performance in business energy supply, particularly in North America and said political intervention in the UK was also a factor.
He added: “The combination of political and regulatory intervention in the UK energy market, concerns over the loss of energy customers in the UK and the performance issue in North America have created material uncertainty around Centrica and although we delivered on our financial targets for the year, this resulted in a very poor shareholder experience.
“We regret this deeply, and I am determined to restore shareholder value and confidence. The underlying trends driving our strategy are clear, as are the distinctive capabilities we have to benefit from them. We are committed to delivering attractive returns and growth over the medium term.”
Its business unit in the UK also saw adjusted operating profit fall by 92% to £4 million last year.