Barclays moved one of its top investment bankers to a new job focused on operations and regulatory compliance on Friday, leaving Rich Ricci as the sole boss of its investment bank.

Jerry del Missier - who had run the corporate and investment banking business jointly with Ricci since late 2010, when previous boss Bob Diamond began his ascendance to Barclays Chief Executive - will become chief operating officer, a position Barclays had left void since 2008.

Banks have been grappling with an onslaught of new international regulations on risk and capital since the financial crisis, prompting many to beef up compliance units.

UK lenders will also be implementing complex new government demands, such as separating their investment bank operations from retail operations - one of the key challenges for del Missier in his new role.

A derivatives specialist originally, he had previously had technology and operations-related roles in the investment bank.

Diamond said in a statement on Friday that the move of one of his long-time investment bank lieutenants to the group-wide role was also aligned with the bank's efforts to create a "One Barclays" model.

The firm is trying to better integrate the operating model of divisions such as investment banking and the corporate unit, and in March it dropped the separate brand names the units had operated under.

Ricci, also an experienced operations manager and one-time chief operating officer of corporate and investment banking and wealth management, will now run Barclays' main profit driver alone.

The investment bank, built up by Diamond over a decade, and which snapped Lehman Brothers' U.S. operations in 2008 after its collapse, has been hit like rivals by slumping trading revenues after several quarters of intense market volatility.

The unit, known as one of the big bond trading players, did better in the first quarter, but heightened euro zone fears that have rocked markets since April will likely hit second quarter income, and that of peers.

Like rivals, Barclays has also been keeping a close eye on costs, and Ricci will also have a key role in managing pay for investment bankers.

Big bonuses are still a thorny topic in the UK after the financial crisis, and Ricci and del Missier have been among the best paid executives at Barclays.

Barclays has not had a group COO since 2008, when Paul Idzik, who used to work under former CEO John Varley, left. He was also an investment bank alumnus and was well known for his colourful management style.

He reportedly once vaulted security gates at the bank to test his staff's reaction.

(Reporting by Sarah White; Editing by Hans-Juergen Peters)