National Grid boss Steve Holliday is to leave the company in early 2016, after 14 years with the company and nine as chief executive.
Holliday previously worked at US oil major Exxon and was a non-executive director of Marks & Spencer until July last year.
The FTSE 100 company may be considering a number of strong internal candidates, according to the Sunday Times, which first reported the news of Holliday’s departure.
National Grid declined to comment.
Last year saw the company suffer a four per cent drop in pre-tax profits to £2.6bn, while growing earnings per share by nine per cent, from 53.5p to 58.1p.
Electricity transmission made up the largest part of the utility firm’s total operating profit, at £1.3bn. This was a 16 per cent increase on the previous year, driven by the introduction of new products in a bid to combat a reduced supply margin.
The group invested around £3.5bn in improving essential infrastructure across its businesses, including £1.8bn in the UK.
Meanwhile, the firm has come under pressure after the “Big Six” energy providers were lambasted by MPs for their large profits and failure to deliver value-for-money to customers.