The agency is believed to have pitched against 12 other firms for the business.
Plans already in place focus on boosting the Stationery Office's reputation as a provider of what the firm called 'information management services'.
Agency CEO Chris Lewis is leading the account team, which will report to the client's corporate marketing director Paul Ellis.
Ellis said: 'TSO has a 200-year inheritance of secure no-fail delivery as a contract publisher to Government and Parliament.
We are now extending this to provide services to help private and public sector companies plan, manage and disseminate their information.'
The Stationery Office is Britain's largest publisher by output, issuing 15,000 publications, CD-ROMs and related products each year. Its clients include the UK parliaments and assemblies, the Office of Government Commerce and the Driving Standards Agency. In the non-government sector, they include BT and the British Retail Consortium.
The Stationery Office was privatised from HMSO in 1996. It has 750 employees and revenues of £78 million per annum.