Franz Holzinger studied at the Vienna University of Technology, was a pioneer officer in the First World War and suffered a serious wound in 1917. A year later, he had recovered sufficiently to join Stern und Hafferl AG, which was to become OKA (the predecessor company of Energie AG Oberösterreich) after 1945.
As a result of his successes, Holzinger became deputy director of the company’s own electricity works in 1923. He developed several improvements, such as the design of a grate for firing waste coal dust, a wood crushing plant, the construction of a floating lowering pump plant and a storage pump at the Gosauwerke.
In 1929, Stern und Hafferl AG merged with Oberösterreichische Wasserkraft GmbH. In the newly created company Oberösterreichische Kraftwerke AG, Holzinger became sales director and later senior director in Gmunden. In 1938, he was appointed deputy general manager.