US business Pennsylvania Power and Light (PPL) is set to buy German energy firm E.On's UK power network in a deal worth $4bn ($6.5bn).

The deal will close in early April and will make PPL, which already owns a UK grid in South Wales and South West England, one of the largest electricity distributors in Britain in terms of regulated asset value, which PPL says is a combined £4.8bn ($7.8bn).

PPL 's offer trumped a rival bid from Hong Kong billionaire Li Ka-Shing, who bought the UK networks of French power group EDF last year.

E.On is selling its Central Network division, which supplies electricity to over five million people, via an 80,000 mile power grid in the Midlands.

The German firm plans to sell £15bn euros of assets by 2013 but still owns operations in the UK and sells gas and electricity to households and businesses.