The two-and-a-half-year contract, due to start on 2 January 2002, is part of a scheme designed to resolve long-standing problems in the service's information systems strategy.
Earlier this year the National Audit Office criticised the Home Office over the state of the probation service's IT. Auditors found mismanagement and said the controversial Crams case management system is difficult to use and unable to keep pace with changing business needs.
A Whitehall source said, "This is a contract to tide the probation service over."
There will be a new contract to replace Crams in 2003 or 2004, he added.