The European Commission has fined French building materials giant Lafarge and three other companies 478m euros (�306m; $475m) for fixing the price of plasterboard, a common building material.

Lafarge - which has said it will fight the ruling - was fined 249.6m euros, while Britain's BPB must pay 138.6m euros, Germany's Knauf 85.8m euros and Belgium's Gyproc 4.32m euros.

The fine, the second largest ever handed out by the Commission, was because the cartel controlled 80% of the European market, worth 1.2bn euros in 1998 when it ceased operating.

The Commission said the larger penalty against Lafarge, which was also fined for running a cement cartel in 1994, would have "a real deterrent effect".

Earlier this year the Commission imposed its biggest ever fine of 855m euros against companies running a vitamin cartel.

Concrete evidence

While BPB and Gyproc cooperated with the plasterboard investigation, the Commission said Lafarge had failed to do so.

Lafarge, the world's largest cement producer, has vowed to fight the ruling.

"Lafarge vigorously challenges this decision and will immediately bring the case before the Court of First Instance in Luxembourg, which has jurisdiction over such matters," it said.

The Commission said the plasterboard cartel began in London in 1992 when BPB and Knauf agreed to stop competing in the German, French, British and Benelux markets.

Lafarge joined later in 1992 and Gyproc in 1996 and the cartel operated until 1998, it said.

A subsidiary of BPB was fined in 1994 as part of a cardboard cartel.

Shares in Lafarge and BPB lost ground after the news.