The move marks the second large business win for Business Post since it began operations in the UK in May. The other is believed to be Singlepoint, the Vodafone-owned mobile phone network.
Business Post's UK Mail division will handle around 30m-35m items for the giant utilities company this year, including bills and direct mail.
UK Mail is understood to be targeting telecoms and ultiities firms, government agencies and mail order companies.
UK Mail collects and sorts mail from its customers, which is then taken to Royal Mail to deliver.
Paul Carvell, chief executive of UK Mail, claims that the company will generate £13m-£15m of revenues this year. By the end of its third year, the company aims to be turning over £150m a year, giving it around 3% of the domestic postal market. Business Post's shares climbed from 7.5p to 539p yesterday.
Powergen is the UK's second-biggest energy supplier with 6m domestic gas and electricity customers.
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This article was first published on brandrepublic.com