ENW, which owns the north west’s electricity network, said the deal to buy United Utilities Electricity Services would help the firm deliver a planned £1bn investment in infrastructure over the next five years.

Steve Johnson, chief executive of ENW, said: “Incorporating our operations and maintenance contract into one business will reduce costs, improve efficiency and secure continued delivery of all services to customers in the region.”

Johnson added: “By creating a single company we will be well placed to ensure the delivery of this vital infrastructure and support the move to a low carbon economy in the north west.”

Today’s deal will see 1,400 United Utilities staff transfer to Birchwood-based ENW from 1 July.

United chief executive Philip Green said: “The sale is consistent with our strategy of focusing on our core activities.”

Mr Green added: “I’m confident with the increased focus around our regulated activities we will become the leading water provider in the UK.”