CRH is being sued for over $120 million (€92.5 million) in the US amid claims that its affiliates used "illegal" dominant market positions in New York to acquire a competitor, Port Dock, at a price "far below fair market value".

The case also alleges that the Dublin-based aggregates and building materials giant subsidiary Tilcon exploited the ill-health of Port Dock's founder to secure his signature on the sale contracts and that the acquisition may not be legally binding.

The antitrust complaint is being pursued by Port Dock Holdings, which sold its aggregates distribution business to Tilcon in 2000 for $10.1 million. Port Dock Holdings retains other assets such as property and a restaurant business. Tilcon is owned by Oldcastle Materials, CRH's major US subsidiary.

Port Dock Holdings claims that it was put in a position where it was "forced" to sell the assets at a "fraction of their true value" because Tilcon had engaged in a sustained effort, both before and after its 1996 acquisition by Oldcastle for $270 million, to push Port Dock out of business by creating "monopoly power" in aggregates sales and distribution in Long Island and the New York City metropolitan area.

CRH has rejected the allegations as "totally baseless".

Recently filed court documents allege that Tilcon told Port Dock that if it did not accept its offer to buy the assets, that Tilcon would no longer use Port Dock as a distributor for its products. The action additionally contends that because Tilcon had bought out all other entities from which Port Dock could have sourced products, that Tilcon had "sealed Port Dock's doom".

It is claimed that at the time of the acquisition, Sam Albicocco, Port Dock's founder, was in "failing health" and that Tilcon put pressure on him to agree to an ultimatum to sell his business. Mr Albicocco has subsequently died.

A lawyer for Port Dock Holdings, John Sachs, has asserted that the sale may not be legally binding as it is alleged that Mr Albicocco was not empowered to sell some of the firm's assets.

Port Dock's legal team believes a fair value for the business would have been "a minimum" of $40 million, as in years before its acquisition it was netting between $4 million and $6 million in annual profits.

If the case goes to trial and the verdict is in Port Dock's favour, it is seeking at least $120 million, as compensation awarded in anti-trust cases in the US are automatically tripled. Punitive damages are also being sought.

A CRH spokesman said the acquisition was a "legally binding transaction that fairly valued the assets and position of Port Dock solely as a distributor of aggregates".

The case has been previously rejected by the first district court in New York but the action was refiled by Port Dock Holdings last month in an appellate court. Any further appeal to hear the case on anti-trust grounds would have to go to the US Supreme Court.