Brussels, 07/12/2001 (Agence Europe) - The European Commission has decided to carry out a more detailed investigation into the proposed acquisition of Aventis Crop Science (ACS), an agro-chemicals subsidiary of the French-German pharmaceuticals group Aventis, by German Bayer. It expresses reservation about this operation that could quite substantially reduce the market for agrochemical products used by the agricultural sector as well as that of anti-parasitic products for pets (mainly ticks and fleas), sectors in which both parties are present. The Commission particularly fears the strengthening of a dominant position on the insecticide market for the protection of various crops, following the meeting of the Bayer and ACS product range of neonicotinoids and pyrazoles, two new and very effective chemical substances. Bayer is the main manufacturer of the former while ACS is the only producer of the latter. Other markets will also be affected by the operation: that of herbicides for the protection of cereals, maize and sugar beet, fungicides for the protection of vines, and products to treat seeds and fight against parasites in pets. The Commission currently has four months at most in which to give a verdict.