In January 1997 the company main owner, the state, agreed about selling main part of Sisu corporation to Partek. This was carried out by gradual shift of the ownership during the year. In the meantime, the state continued the restructuring: Germany based Stama Maschinenbau GmbH was sold to Chiron-Werke GmbH & Co. KG. Sisu Defence went to the state, which later joined it to new defence industry company Patria. Oy Sisu Ab was fully taken over by Partek by end of 1997 and it was not mentioned any more as a company in the Partek annual report.