German energy firm E.On has agreed to buy rival Ovo in a deal which would create Britain’s largest supplier. The combined business will serve about 9.6 million customers, surpassing current top supplier Octopus. The firms did not disclose the value of the deal, although previous reports indicated that it could be as much as £600 million. The takeover is subject to regulatory hurdles, including potential scrutiny from the UK’s competition watchdog, and is expected to complete in the second half of 2026. Both firms said there would be no change for customers while regulators review the deal and that tariffs would be “honoured in full”. E.On and Ovo will continue to operate separately until the deal is approved. Stephen Fitzpatrick, founder of Ovo, said: “ Energy retail is now more regulated, more capital intensive and increasingly dependent on long-term investment and scale.…