Governance inspectors from the Crown Prosecution Service Inspectorate (HMCPSI) said in May that Green had too many responsibilities as head of the SFO, Britain' leading fraud, bribery and corruption prosecutor and investigator.

It said many of the corporate and business duties he had taken on and shared with his senior civil service group were normally the remit of a chief executive. The SFO has had no CEO or COO since a senior management shake-out after Green overhauled the agency on his appointment in 2012.

Like many SFO staff, Thompson is a former police officer and also a qualified accountant. He joined the SFO in 2004, became head of proceeds of crime in 2012 and chief finance officer in 2015.

Green said the appointment of Thompson, who will retain his CFO duties, would bring "cohesion and clarity" to the SFO's corporate and business duties and "a strong focus on ensuring value for money".

The heads of the SFO units responsible for international assistance, human resources and IT systems will report to Thompson. The chiefs of the bribery and corruption divisions, fraud divisions and proceeds of crime division report to SFO general counsel Alun Milford.

Thompson, Milford and Kevin Davies, the chief investigator in charge of the agencies' intelligence, evidence handling and forensics units, report to Green, who maintains overall responsibility for the SFO's strategic direction, case decisions and organisations management.

Thompson's position as head of proceeds of crime will be filled on an interim basis by Elizabeth Baker, former joint deputy head at the division, a spokesman said.

The SFO current high-profile cases include an inquiry into Barclays' (>> Barclays PLC) 2008 emergency fundraising from Qatar, allegations of bribery and corruption at Rolls-Royce (>> Rolls-Royce Holding PLC) and Airbus (>> Airbus Group) and investigations into commercial practices at GSK (>> GlaxoSmithKline plc) and accounting practices at retailer Tesco (>> Tesco PLC).

Three former Tesco executives were charged with fraud and false accounting last month.

(Reporting by Kirstin Ridley; Editing by Greg Mahlich)