The French competition authority is fining 34 construction companies, including Bouygues, Vinci and Eiffage, £33.56m for operating a cartel in public contracts around Paris between 1991 and 1997.

Bouygues and its subsidiaries will be fined £7.3m, according to documents produced by the authority. Eiffage will be fined £4.4m, and units of Vinci £1.6m. The biggest individual fine, £3.9m, has been levied on privately owned Soletanche Bachy France.

The authority, Conseil de la Concurrence, said that the fines relate to about 40 tenders worth about *1bn, or £692m. The deals are said to have included contracts awarded by French national railway operator SNCF and public transport operator RATP.

This month Bouygues revealed that its 2005 earnings had been affected by anti-trust fines over its construction businesses in the fourth quarter. As Building went to press it was unclear whether the French authority's announcement referred to the same cases.