Australia's Origin Energy on Dec.18 increased its stake in U.K.-based renewable energy firm Octopus Energy by 3% to 23%, by investing £280 million (US$354.12 million).

Origin is investing alongside existing major investors Canada Pension Plan Investment Board (CPP Investments) and Generation Investment Management (GIM), it said in a statement.

CPP Investments will invest £300 million to raise its stake in Octopus to 11% from 6%, while GIM will invest £45 million, maintaining its interest of around 10%.

This latest capital raise is being executed at a pre-money valuation of £5.6 billion, which represents a 60% increase in the value of Octopus since December 2021, Origin said.

Octopus is now the U.K.'s second-largest energy retailer and its platform Kraken is contracted to serve over half of U.K. households and licensed in ten countries, which is critical in a rapidly transforming energy system, Origin CEO Frank Calabria said.

The transaction is subject to investors obtaining required regulatory approvals, with Origin's additional investment requiring approval from the U.K.'s Financial Conduct Authority, the company said.