Building materials companies CRH and LafargeHolcim are contesting the final price of CRH's acquisition of assets from the Swiss-French company, the two companies said.

CRH agreed to buy the assets for €6.5 billion in February last year after they were put up for sale so then separate Holcim and Lafarge could get antitrust clearance to create the world's biggest cement company.

“LafargeHolcim has received from CRH several notices claiming a reduction of the purchase price. LafargeHolcim is contesting those claims,” the Swiss-French company said in its annual report, published on Thursday.

“In view of the information available to the management and on current analysis, CRH’s claims to a further price reduction under the price adjustment mechanism in the sale agreement are considered to be without merit and are not accepted.”

CRH said in its annual report, also released on Thursday, that it was engaged in a process to finalise the post-completion consideration that was “not sufficiently advanced to make a financial adjustment in respect of the final purchase price”.

A source familiar with the deal said on an acquisition of this size and complexity, such a process was “not unusual”.

The deal closed at the end of July and the final assets moved to CRH in September, transforming the Irish company into the world’s third-biggest building materials supplier and helping boost its 2015 earnings by 35 per cent.

- Reuters