After a brief time in the Ministry of Finance in 1945,[2] to which he was summoned by Wilhelm Thagaard,[3] he returned to the Price Directorate and remained here until 1949.
[2] When hired as deputy under-secretary in 1951, Lorentzen edged out applicants who were generally believed to be better qualified, especially Einar Grøstad.
[5] He became quite strong; historian Einar Lie has noted that "in reality", the permanent under-secretary of state Friedrich Georg Nissen did not function "as a real superior to Lorentzen".
However, this time Trygve Bratteli chose economist Eivind Erichsen; Grøstad and Lorentzen were both jurists.
Einar Lie wrote that when Trygve Bratteli brought Lorentzen to the Ministry of Transport, he "solved" a problem.