Work included carrying out maintenance at 450 corporate properties plus the bank's global headquarters at Canary Wharf in London's Docklands.
But Carillion was unhappy with the amount of insurance risk it was being asked to carry at Canary Wharf.
A Carillion spokesman said: 'We operate a rigorous risk assessment procedure, which applies to every contract.
'The nature of the discussions with Barclays was such that Carillion felt it had insufficient time to apply its risk assessment criteria thoroughly.'
The deal was worth around £50 million. It has now gone to US firm Johnson Controls, which Mowlem had originally beaten to the contract.