HeidelbergCement turned down a merger with Holcim, following discussions in late 2013 between Holcim chairman Rolf Soiron and HeidelbergCement’s biggest shareholder, Ludwig Merckle, who owns 25 per cent of HeidelbergCement shares through the family-run Spohn Cement, according to reports in SonntagsZeitung newspaper.

"Right before the talks with Lafarge, Soiron discussed a merger with Heidelberg," the Swiss newspaper quoted one of the sources as saying. "Heidelberg declined it, though, because a merger among equals was not possible."

The deal between Holcim and Lafarge was announced in April 2014.