UBS Warburg has re-established its relationship with Aventis as co-lead adviser to the Strasbourg-based pharmaceuticals giant on the €8bn ($6.8bn) sale of its crop science unit to Bayer, the German chemicals company.

Aventis turned to UBS Warburg to advise alongside Goldman Sachs on the sale of Aventis Crop Science, its majority-owned agrochemicals division, to Bayer. Bayer's bid beat off a rival offer from BASF, the German chemicals and pharmaceuticals giant, advised by Dresdner Kleinwort Wasserstein.