Barclays said it will pay incoming chief executive James "Jes" Staley up to £8.24 million a year after appointing the former JPMorgan investment bank boss to one of the most prominent posts in British business.

Mr Staley (58) will join Barclays as chief executive at the start of December, having been widely expected to be appointed after sources and other media reports this month said he had been chosen and just needed regulatory approval.

He faces a number of challenges at Barclays, including improving its reputation after a series of scandals, cutting costs to try and improve profitability, and deciding how big an investment bank it should keep in the wake of tougher regulations.

Mr Staley said on Wednesday he planned to complete a restructuring of the investment bank and said Barclays must avoid an adversarial relationship with regulators. “We will complete the necessary transformation and repositioning of the investment bank to a less capital-intensive model,” Mr Staley said in a memo to staff.

Barclays chairman John McFarlane said Mr Staley had the appropriate leadership talent and wide-ranging experience to improve shareholder value and take the bank forward. “In particular, he understands corporate and investment banking well, the re-positioning of which is one of our major priorities,” Mr McFarlane said. Investors and analysts have said Mr Staley should improve morale and set a clear strategy for the investment bank after years of uncertainty, but they warned he should not build it back up aggressively.

"We had warmed to Barclays on the basis that it was de-emphasising the relatively low-return investment banking business ... and we would see a material reversal of this strategy as a negative to the investment case," Shore Capital analyst Gary Greenwood said. Mr Staley's appointment is the second time in recent years Barclays has named an American investment banker as chief executive, the last being Bob Diamond who quit in 2012 over the Libor scandal.

Barclays shares were down 0.8 per cent earlier, in a broadly flat European bank sector. Barclays said Staley’s annual pay will consist of a salary of 1.2 million pounds, a role-based “allowance” of £1.15 million in shares, a cash allowance of up to £400,000 and up to £5.5 million in annual bonus.

Reuters