Aventis, the German chemicals group, has devised an innovative way to avoid paying tax on asset disposals well ahead of next year's changes to the German tax code.

In a deal that will alert many of its compatriot companies, Aventis is using a complex set of derivatives to pay zero tax on profits earned from its sale of Messer Griesheim, its gases arm, which it sold for €1.6bn ($1.4bn) in January.