French building materials group Lafarge SA is facing a class action lawsuit in the US from minority shareholders of its Lafarge North America business alleging the price the group is offering to buy the remaining shares in the unit is too low.

Lafarge announced on Feb 6 a US$75  offer for the 46.8 per cent of the North American business it does not already own. This was a 16.7 per cent premium on the share price.

’The US$75 price per share does not adequately value the company in light of its recent, outstanding financial performance as announced on Feb 1 2006,’ said the law firm that filed the suit - Entwistle & Cappucci LLP.

The firm also alleges the offer fails to reflect expected future growth and profitability at the North American business.