Barclays confirmed yesterday that investment banking boss Bob Diamond will become the UK bank's chief executive next spring, as officials tried to dispel the notion that the move represented a fundamental shift for the centuries-old British institution.

Diamond, a baseball-obsessed American who is the architect of Barclays' rise as a global investment banking powerhouse, will replace John Varley, a British graduate of Oxford who is a skilled fly fisherman and hails from Barclays' retail businesses.