Updated

The chief executive of security firm G4S is to retire after a tumultuous year that saw the company fail to fulfill its Olympic contract.

The company said Tuesday that Nick Buckles will be replaced by Ashley Almanza, a senior executive from the oil and gas company BG Group.

G4S had agreed in February to take an 85 million pound hit after failing to provide agreed upon security personnel for last summer's London Olympics.

That figure includes extra costs paid by the government to provide military and police security to cover the G4S shortfall.

Despite the setback, the company has been hired in a support role to help secure the G-8 summit of world leaders in Northern Ireland next month.

The new CEO is scheduled to take over on June 1.