Energy group Shell on Friday said it had sold UK and German units providing gas, electricity and broadband for an undisclosed amount to British company Octopus Energy.
"To drive performance, discipline and simplification, we are prioritising countries, projects, and routes to market where we can deliver the most value," Steve Hill, executive vice-president, Shell Energy, said in a statement.
It comes as British group Shell winds down its home energy retail business in the Netherlands but keeps similar operations in Australia and the United States.
Shell's sale will make Octopus Britain's second-largest domestic energy supplier behind British Gas.
Octopus said it would provide energy for an additional 1.4 million homes and broadband to 500,000 customers, mainly in the UK.
"Octopus has proven that it delivers game-changing service whilst innovating and investing relentlessly towards a cheaper cleaner energy system," its chief executive Greg Jackson said in a separate statement.
Octopus last year acquired 1.5 million customers following the collapse of British energy supplier Bulb.
Energy prices are falling after having surged in 2022 following the invasion of Ukraine by major oil and gas producer Russia.
However, they remain elevated by historical standards, prolonging a cost-of-living crisis for millions of people.