LONDON (Reuters) - Embattled security and outsourcing group G4S could lose out on lucrative public contracts, the group's chairman said, following the furor that has erupted over its handling of security personnel recruitment at the Olympics.

G4S Chairman John Connolly told The Sunday Times he fears the group could be frozen out of future public contracts to run prisons and do back-office police work.

The world's largest security group and its Chief Executive Nick Buckles have been at the centre of a political firestorm since it said it could not provide the promised 10,400 security guards to cover the London Olympic Games, which start in less than a week's time.

"If a contract was being given out by a government department or other large business at the moment, you can understand they would find it difficult to hand that contract to us," Connolly told the newspaper.

On Friday, credit ratings agency Standard & Poor's put the company on alert for a possible downgrade, warning its recent failings could result in the group losing out on future work.

G4S makes more than 1 billion pounds ($1.6 billion) of its 7.5 billion pounds in annual revenues from public sector work and is currently bidding for nine British prison contracts as well as services for the police.

The fiasco around security staffing for the Games is putting pressure on Buckles, who was recently forced to appear before a parliamentary committee.

Buckles position as Chief Executive could come under review, Connolly said in the interview.

"It is inevitable that a part of it will be a discussion about the senior management. Was there enough of a focus on this contract?" Connolly said.

G4S shares closed at 241.7 pence on Friday, some 14 percent lower than before the group's admission it did not have enough security officers to staff the Games.

G4S is the largest employer listed on the London Stock Exchange with more than 657,000 employees and operations in 125 countries that brought in profits before interest, tax and amortization of 531 million pounds last year.

G4S was not available for comment.

(Reporting by Simon Meads; additional reporting Neil Maidment; Editing by Mike Nesbit)