Some 3,500 military personnel will be involved with security at the Paralympics, compared with 12,200 at the Olympics
G4S will provide the majority of security for Paralympic venues as the number of troops and police officers on duty is scaled back, organisers have confirmed.
Locog chief executive Paul Deighton said the private firm, which is facing a loss of £50 million over its failure to provide enough staff for the Olympics, will use 4,000 to 5,000 workers.
Mr Deighton said: "We're fully confident. The military contingent this time will be 3,500 soldiers, with 1,000 in reserve and typically G4S will be between four and 5,000.
"In very simple terms, we're switching from an approach which had a slight majority of military during the Games to one which will have a slight majority of private sector security for the Paralympics."
The number of military personnel has been drastically scaled back from the 12,200 troops involved in venue security during the Olympics.
Police numbers will also be halved, with around 7,000 officers on Paralympic duty across the country, compared with 14,500 previously.
G4S was embroiled in a "humiliating shambles" in the run-up to the Olympics, with ministers forced to draw in extra military personnel after the company failed to provide enough guards.