The lawsuit, which the plaintiffs said was based on interviews and documentary evidence, alleged that by having business relations with the terrorist group, LafargeHolcim was likely complicit in war crimes and crimes against humanity.
The suit alleged that Lafarge Cement Syria (LCS), a subsidiary of LafargeHolcim, would have entered into arrangements with members of the Islamic State (IS) back in 2012, so that the company could keep its factory in the north of Syria running.
The suit said it had evidence that LCS agreed to pay for passes issued by IS in order to cross checkpoints into IS-held territory, and that LCS also agreed to buy a number of raw materials, including oil and pozzolana, in areas under IS control.
Sherpa and ECCHR also filed suit against the cement manufacturer and its subsidiary for reckless endangerment. According to Sherpa, LCS did not set up safety measures suitable to the ongoing crisis in the area in which the plant was situated. It said while foreign employers were repatriated to their countries of origin, Syrian employees kept going to work in spite of the many dangerous checkpoints controlled by IS.
This summer LafargeHolcim said it would investigate the facts and that employee security was paramount to the company.
In July, a parliamentary mission looking into the financing of IS said it wasn't able to establish anything that suggested Lafarge had directly or indirectly financed IS.
LafargeHolcim's share price fell slightly after the announcement of the lawsuit on Tuesday.