Denis Ranque began his career at the French Ministry for Industry, where he held various positions in the energy sector, before joining the Thomson group in 1983 as Planning Director. The following year, he moved to the electron tubes division, first as Director of space business, then, from 1986, as Director of the division's microwave tubes department. Two years later, the electron tubes division became the affiliate Thomson Tubes Electroniques, and Denis Ranque took over as Chief Executive of this subsidiary in 1989.
In April 1992, he was appointed Chairman and CEO of Thomson Sintra Activités Sous-marines. Four years later, he became CEO of Thomson Marconi Sonar, the sonar systems joint venture set up by Thomson-CSF and GEC-Marconi. In January 1998, Denis Ranque was appointed Chairman and Chief Executive Officer of the Thomson-CSF group, now called Thales. He resigned from this position in May 2009, as a consequence of a change in shareholding.
From February 2010 to June 2012 he has been Non-Executive Chairman of Technicolor. Since October 2001, he has also been Chairman of the Board of the Ecole des Mines ParisTech, and since September 2002, Chairman of the Cercle de l'Industrie, an association which unites France’s biggest industrial companies; both mandates ended in June 2012. He is member of the Boards of directors of Saint-Gobain and CMA-CGM. From 2013 to 2017, he chaired The Haut Comité de Gouvernement d’Entreprise, the independent body put in place by the French Code of corporate governance for monitoring and encouraging progress in this field. From 2014 to 2017 he has also been co-Chairman of La Fabrique de l’industrie, a think tank dedicated to industry.
Since 2014 he is the Chairman of the Fondation de l’Ecole Polytechnique and a member of the French Academy for Technologies (“Académie des Technologies”). Denis Ranque, born 1952, is a graduate of France's Ecole Polytechnique and the Corps des Mines.