RWE npower, the UK arm of German energy company RWE, is the UK's largest electricity supplier and the second largest energy supplier to the UK business market, boasting an estimated 400,00 business customers. The company, as both retailer and producer of electricity, along with its gas supply and plant consultancy services, has in excess of 6.8 million retail customers across the UK, with the firm generating revenues of ,8.4 billion for 2006 - a 33 per cent increase on 2005.