THE boss of security firm G4S is to stand down – only months after he came under fire for his company’s botched handling of its Olympics Games contract.

Shares in the group rose three per cent at the news that chief executive Nick Buckles, who was paid a total of £1.2m last year, is to retire from the company. He will be replaced on June 1 by Ashley Almanza, who has held senior roles at oil and gas firm BG Group.

Mr Buckles departs with a £1.18m pay-off, equivalent to what he would receive for his contractual notice period of 12 months. He will receive his basic annual salary of £830,000, a £332,000 pension allowance, plus a £20,000 car allowance.

Mr Buckles has already accumulated a £9.5m pension pot and about £5.4m of shares, giving him a combined financial package of about £16m.

He was instrumental in creating the G4S business through the merger of Securicor and the security businesses of Group 4 Falck in 2004.

G4S’s Olympics failure saw Mr Buckles hauled before MPs, during which he admitted it was a “humiliating shambles for the company”.

Extra military personnel had to be called in to fill the gap left by G4S’s failure to supply enough staff for the £284m contract.

Chief operating officer David Taylor-Smith and Ian Horseman Sewell, who was head of global events, carried the can for the fiasco, but Mr Buckles stayed in his post.

However, pressure has intensified on Mr Buckles in recent weeks, after a poor trading update caused shares to slump by more than 13 per cent in one day.

G4S disappointed investors by revealing that weak European markets and pricing pressure on its cash transportation arm in the UK and Ireland had squeezed margins.

G4S is the largest employer on the London Stock Exchange with more than 620,000 staff worldwide.

Chairman John Connolly said: “Nick Buckles made a massive contribution to the group over a 28-year career.

“As chief executive, he led G4S in the creation of significant shareholder value following the merger of Securicor and Group 4 Falck – building the world’s leading security company.”

Mr Buckles was appointed chief executive of Securicor in 2002 before taking the top role in the newly-created G4S business.