BT executive Liv Garfield was named as chief executive of Severn Trent yesterday, taking the number of women running FTSE 100 companies to four.

Garfield – who spearheaded BT’s £2.5 billion Openreach super-fast broadband rollout – joins Alison Cooper at Imperial Tobacco, Easyjet’s Carolyn McCall and Angela Ahrendts at Burberry.

Ahrendts is due to join Apple next year but Moya Greene, who runs Royal Mail may well see her newly-listed company promoted to the FTSE 100.

Garfield will replace Tony Wray next spring to lead a utility that spurned three takeover bids from a Canadian-led consortium in June.

Analysts said her move was a blow for BT, where she held a several top positions including head of strategy.

Shares in BT, which said it would announce a replacement in due course, fell one per cent while shares in Severn Trent were down 0.6 per cent.

“It has been a tough decision but I leave Openreach in fantastic shape and have every confidence it will continue to thrive,” Garfield said.