The Department for Work and Pensions has signed a seven-year application development and maintenance contract with Accenture for parts of its Universal Credit system and other customer-facing systems.
The deal is worth between £50 million to £70 million per year, depending on DWP demand for IT services, Accenture said.
Accenture has partnered with Atos for the deal and will collaborate with HP the DWP's main IT outsourcer and other suppliers.
The core of the contract will see Accenture deliver application development and maintenance services for the Application Suite used by external customers who contact DWP for benefits directly, via the telephone or Web site.
The application development and maintenance services that Accenture will provide will help DWP make substantial cost-savings, deliver key programs, such as Universal Credit, and provide the most appropriate services to citizens.
Mark Lyons, Accenture's UK and Ireland managing director for Health & Public Service said, "Accenture will help DWP drive significant and sustainable cost savings. This new contract builds on our longstanding relationship with DWP and the successful delivery of similar projects with other public-sector clients."
The DWP raised eyebrows last month when it handed two more major contracts to HP - for a core benefit systems and departmental help desk and application support. HP already had major contracts for hosting, integration and desktops at the Department
In September the DWP handed seven-year application maintenance contracts to Cap Gemini and IBM.