Two top executives have resigned at British security giant G4S after it failed to provide enough guards for the London Olympics, but its chief executive will keep his job, the company said Friday. David Taylor-Smith, chief operating officer, and Ian Horseman Sewell, managing director of global events, will leave in the wake of the fiasco, G4S said in a statement. But under-fire Nick Buckles will retain his job despite the fact that the government had to draft in 4,700 British troops at the last minute to satisfy the Games' security requirements. "The board confirms that it is in the best interests of the company and of all its stakeholders that Nick Buckles should remain group CEO," G4S said, following an internal review of its handling of the Olympics contract. "Whilst the CEO has ultimate responsibility for the company's performance, the review did not identify significant shortcomings in his performance or serious failings attributable to him in connection with the Olympic contract." G4S said the board "has accepted the resignations" of Taylor-Smith and Horseman Sewell. The firm faced an inquiry by MPs after it announced just days before the Olympic Games that it could not completely fulfil its £284-million ($461 million, 355 million-euro) contract to provide 10,400 security staff for venues. Buckles has previously apologised and said he was "deeply disappointed" about the shortfall. G4S has said the episode will cost the company about £50 million as it struggles to recover from the fiasco. Pre-tax profits slumped 60 percent to £61 million in the six months to the end of June, hit also by restructuring costs after it slashed 1,100 jobs worldwide. Net profits tumbled 74 percent to £30 million. The company said Friday it would "take a number of further actions, learning lessons from this contract," including stricter risk assessment for new contracts and better project management.