Tietotehdas was the root company of current Tieto Corporation. Tietotehdas Oy started its business operations in Espoo, Finland in 1968. During the first years, Tietotehdas operated mainly in its owners' computer centre. IT systems were developed and maintained mainly for Union Bank of Finland and its customers, and for a few forest industry companies.
The customer base of the company grew during the 1970s, when mini-computers were introduced alongside the existing mainframe computers. Besides mainframe computer services and software, the development of IT systems was also central to the operations of Tietotehdas. Customers represented several industries and operations were organized according to these verticals. During the 1990s, the company experienced rapid growth through a number of acquisitions, mergers and strategic alliances. The company's name was changed from Tietotehdas to TT Tieto in 1995 and Tieto in 1998. In 1996, the company strengthened its exposure in the telecom sector considerably through the acquisition of Avancer. In 1999, Tieto and Enator merged, and TietoEnator was born.
On 1 December 2008, the company launched a new corporate brand and marketing name Tieto (which means knowledge in Finnish). The official registered name of the company is now Tieto Corporation.
Starting from year 2009, Tieto went with an aggressive strategy of offshore production, reaching up to the end of the decade.