NEW DELHI -- India’s anti-trust regulator, the Competition Commission of India, or CCI, said Saturday that it had begun public scrutiny of of a proposed merger between cement makers Holcim Limited and Lafarge S.A.. The deal would create one of the largest cement companies in the world.

The CCI said in a statement, that it had “formed a prima facie opinion that the combination is likely to have an appreciable adverse effect on competition,” and had therefore “directed Holcim and Lafarge to publish details of the combination for bringing the combination to the knowledge or information of the public and persons affected or likely to be affected by such combination.”

The CCI has directed the companies to publish the details of the combination in all India editions of four leading daily newspapers, including at least two business newspapers, and also host the same on their respective websites.

In April, Holcim of Switzerland unveiled a deal to buy French company Lafarge, to create the world's biggest cement maker, with $44 billion of annual sales, it was reported.

The companies billed the industry's biggest ever tie-up as a merger of equals, under which Lafarge shareholders receive one Holcim share for every Lafarge held and Holcim investors end up with 53 percent of the new group. The merged entity will be based in Switzerland and listed in Zurich and Paris, Reuters had further reported.

This is only the second time that India’s five year old antitrust regulator has directed two companies engaged in a merger to submit to public scrutiny. Earlier, in July, the CCI had asked pharma companies Ranbaxy Laboratories Ltd and Sun Pharmaceutical Industries Ltd to make the details of their proposed merger open to scrutiny.