The UK electricity supplier Innogy, which trades under the name Npower, is to be acquired by the German company RWE for close to ¤5 billion plus a further ¤3.9 billion debt. The move will leave more than half of the electricity supply industry in the UK under the control of non-UK companies.

The acquisition has also been seen as the latest stage of a battle between RWE and its German rival E.On. The latter will acquire Powergen in May for ¤10 billion, including debt.

Innogy, which demerged from National Power in October 2000, has since acquired energy retail companies Yorkshire Power and Northern Electric. It now has around 5.2 million electricity customers and 1.8 million gas customers making it the second largest energy supplier in the UK after Centrica which owns British Gas.

Since gas competition was launched in the UK in 1996 the number of energy supply companies has fallen from fifteen to eight. With completion of the RWE deal, five will be owned by foreign concerns.

For RWE, the Innogy deal represents its fourth big acquisition in two years. It bought the UK company Thames Water in 2000 for ¤7 billion, American Water Works for ¤8.4 billion and the Czech gas distributor Transgas for ¤4 billion.