Brydon has been in the role since 2009 and oversaw the company's controversial privatisation in October 2013. He will continue to chair the Royal Mail board until at least its annual general meeting in the summer, the firm said.

"Our transformation is well underway and we are now a FTSE 100 listed company. I feel that now is the right time for me to make this decision," Brydon said in a statement.

(Reporting by Neil Maidment; editing by Kate Holton)