Chris Mellor spent 24 years with the company

Chris Mellor resigned from AWG after the board called for new leadership to take the business forward.

He will receive a payout of about �350,000 including 12 months salary and benefits.

Chairman Peter Hickson will assume the role of executive chairman until a replacement for Mr Mellor is found.

AWG has spent much of the last year restructuring its business, focusing not just on utilities but also on support services and infrastructure management.

'Significant contribution'

A spokesman for the Huntington-based group said: "Chris's experience was very much in the water industry but clearly the growth is going to come from those infrastructure management businesses.

"The board decided it was time for a change in leadership."

The company said that finance director Elliott Mannis, who said in November that he would step down in April, has agreed to stay on.

The spokesman said the business, which is due to issue a trading update at the beginning of next month, was in "good shape".

The company's statement also said: "The board wishes to acknowledge Chris's 24 years with the company and his significant contribution to both the company and the water industry, particularly since privatisation."