Holcim looked at buying Germany's HeidelbergCement towards the end of 2013 before agreeing to merge with France's Lafarge , a Swiss newspaper reported on Sunday, citing two sources. Then-Holcim chairman Rolf Soiron spoke with HeidelbergCement's biggest shareholder, Ludwig Merckle, who owns around 25 percent of HeidelbergCement shares through the family-run Spohn Cement, the SonntagsZeitung newspaper reported. "Right before the talks with Lafarge, Soiron discussed a merger with Heidelberg," the Swiss newspaper quoted one of the sources as saying. A spokesman for Zurich-based Holcim declined to comment on the report.