The European Commission, the antitrust regulator in Europe, has objected to plans by Cemex to acquire Spanish units held by Holcim.

In August last year the two cement majors reached an agreement to conduct a series of transactions to swap and combine assets in parts of Europe with the aim of improving synergies and boosting operating profit.

However, a source told Reuters last week that: "The European Commission (EC) has sent a statement of objections to the companies," referring to a document which backs up the EU watchdog's views that the deal would be a significant impediment to competition.

Reacting to the news, a Cemex source told the news agency that the company had offered some concessions during the Commission's preliminary review but these were not considered to be sufficient. The Commission has set a 5 September 2014 deadline for its decision.

 In June Holcim received unconditional clearance by the EC for its proposed acquisition of Cemex West in Germany. The proposed acquisition of Holcim Cesko (Czech Republic) by Cemex was cleared by the local competition authorities in March this year.