The agency was brought in to handle UK financial media and corporate announcements for the RWE-owned firm because its activities affect so many UK investors and customers – it has around 6.8 million customers and is the UK’s largest electric supplier.
The energy provider used Finsbury before its acquisition by RWE in 2002, but has not worked with the agency since then.
Npower hit the headlines last month when its plans for a wind farm near Bradwell-on-Sea, Essex, were approved. If built, it hopes the farm will provide power for up to 10,600 local homes.