G4S said its loss on the London Olympic security contract would stretch to 70 million pounds after finally agreeing a settlement with Games organisers.

The world's biggest security firm's reputation was badly tarnished when it admitted just weeks before last year's Olympics it could not provide 10,400 guards for the Games, forcing British troops to fill in and embarrassing government, a key client.

G4S, which was subsequently hauled before British MPs to explain the debacle and later let two executives go after an internal report, had estimated the loss on the contract worth around 240 million pounds to be around 50 million pounds.

The group said it had also incurred additional costs of approximately 11 million pounds, relating to charitable donations and external fees and a further 7 million relating to the cost of sponsorship and marketing. All of these costs will be taken in the 2012 accounts as an exceptional charge, it said.

(Reporting by Neil Maidment; Editing by Paul Sandle)