Under the deal, the Norwegian energy major will supply an additional one billion cubic metres (bcm) of natural gas per year.
The increased volume will be enough to meet the heating needs of an additional 4.5 million British homes.
The new deal brings Centrica’s total gas supply volume agreed with the Norwegian firm to more than ten billion cubic metres a year, representing approximately 12% of UK’s total gas demand.
Centrica said that the gas supply deal, amid a ‘difficult geopolitical and macroeconomic environment’, would provide the country with further energy security.
UK Business and Energy Secretary Kwasi Kwarteng said: “With Russia’s criminal invasion of Ukraine, it is more important than ever that we source more of the gas we need domestically, but also from safe and reliable import partners while we transition. We cannot, and will not, turn off the taps overnight.
“This major supply deal agreed today will help underpin British energy security over the next few years, and also reinforce our partnership with Norway as a key international energy ally.”
Equinor supplies 20bcm to 22bcm of natural gas to the UK annually, meeting more than 25% of the country’s gas demand.
Centrica Group CEO Chris O’Shea said: “As Britain’s biggest gas and electricity supplier, we take our responsibility to over eight million British Gas domestic and business customers very seriously.
“This important agreement with Equinor underpins vital domestic supplies and strengthens the strategic relationship between the UK and Norway.’’
Earlier this month, Equinor announced that it had signed a long-term sales and purchase agreement (SPA) to buy liquefied natural gas (LNG) from Cheniere Energy.