Aventis & Sanofi

The acquisition of Aventis by Sanofi: Attack as defense


This is a combined version of the four-part case series. The year 2004 started with a bombshell for the mergers and acquisitions sector: On 24 January rumours emerged of an imminent takeover bid by Sanofi-Synthelabo to the shareholders in Aventis. On 25 April the first hostile takeover in the history of the pharmaceuticals sector was completed. The Chief Executive Officer (CEO) of Sanofi and future CEO of Sanofi-Aventis, Jean-Francois Dehecq, commented ‚I had a very strong feeling that if we didn’t do this deal now then one of our international competitors would have bought either Aventis or Sanofi‘. The aim of this case is to describe an entire merger and acquisition process, against the background of a pharmaceuticals industry undergoing highly dynamic competition and consolidation. The case is outlined in the form of the chronological activity of the actual takeover battle, from the first rumours through to integration, in four phases: (1) from the attack by Sanofi-Synthelabo, which the management of Aventis initially considered as hostile; (2) via the battle for Aventis; (3) to the ultimately amicable unification of the two companies; and (4) the integration of Sanofi-Aventis.

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Bibliographic Data


Case – Reference no. 306-237-1

Authors: Mueller-Stewens, G. (University of St. Gallen); Alscher, A. (University of St. Gallen)
Published: 2006
Length: 65 pages
Data source: Published sources

Teaching note – Reference no. 306-237-8

Authors: Mueller-Stewens, G. (University of St. Gallen); Alscher, A. (University of St. Gallen)
Published: 2006
Length: 24 pages
Data source: Published sources

Contact person

If the case study is not available at The Case Centre, or if you have any questions about additional material or application of the case study, please contact the author.

Günter Müller-Stewens

Prof. em. Dr.
Ordentlicher Professor em. für Betriebswirtschaft