Diamond, a US national and one of the world’s highest-profile bank executives who famously brought off the bank’s audacious purchase of much of Lehman Brothers two years ago, will, from 1 October, take on the post of president and deputy CEO, Barclays said in a statement. He has been a board member since 2005.

The changes will not affect the management structure of Barclays Wealth. Tom Kalaris continues as CEO for Barclays Wealth and his reporting line remains unchanged, a spokesperson told WealthBriefing.

As a result of the changes, Varley will become a senior advisor on regulatory matters to Bob Diamond and to the board of Barclays until 30 September 2011, the statement said. Jerry del Missier and Rich Ricci will become co-chief executives of Barclays Capital, effective 1 October, in addition to being co-chief executives of the corporate and investment bank.

Varley’s period at the helm of Barclays has coincided with a bruising merger and acquisition battle in which the bank lost – arguably fortuitously – its bid to buy Dutch bank ABN Amro, losing out to a consortium of banks including Royal Bank of Scotland. However, unlike RBS and another consortium bank Fortis, Barclays was relatively unscathed by the credit crunch and has not been bailed out by taxpayers’ money. On his watch, Barclays also spun off its Barclays Global Investors arm, selling to BlackRock, creating the world's biggest asset management firm.

The investment bank of Barclays – Barclays Capital – has seen its fortunes wax under Diamond’s leadership. In 2008, Barclays executed a sudden purchase of much of Lehman Brothers’ business after this firm filed for bankruptcy in the autumn of 2008. The ascent of Diamond, who comes from Concord, Mass, has been seen as an example of the growing importance of North America to Barclays’ overall strategy as a bank. He joined Barclays in 1996.