He will take up his board role in January 2015 while retaining his regulatory oversight position at FRC, where he has been chairman since May 2014, when he replaced Baroness Hogg who retired.

He is contracted for two days a week at FRC with remuneration of £120,000 per annum. The JP Morgan role is expected to be two-day a week.

The appointment has been approved by the banking sector’s regulators, the Financial Conduct Authority and the Prudential Regulation Authority. He will replace Tom Hoppe at JP Morgan Securities.

The FRC rejects any potential conflicts of interest and in a statement said: ‘The FRC has a diverse board many of whom sit on boards of various companies.

‘The FRC believes it is important to have those with a wide breadth of experience on the board as it oversees the FRC’s work towards promoting high quality reporting and governance to foster investment.

‘Regarding conflicts of interest: the FRC’s Conduct Committee decides whether to commence an investigation but Sir Win is not on the Conduct Committee and in any event, potential and actual conflicts are closely monitored.’

When in post, Baroness Hogg was on a number of boards, including John Lewis, while Keith Skeoch, current FRC non-executive director, is on the board of Standard Life Investments.

Before joining the regulator, Sir Win was chairman of Lloyds Banking Group from 2009, and chairman of Citigroup Europe from 2000 to 2007. He became the acting CEO of Citigroup Inc in 2007 and was subsequently appointed as chairman in the same year until his retirement in February 2009. Prior to this, he was the group chief executive and then chairman of Schroders.