highest court will on Tuesday rule on whether cement giant should remain charged with complicity in crimes against humanity over alleged payments made to Islamist militants in at the height of the country's civil war.
The French company is suspected of paying nearly 13 million euros ($15.3 million) to (IS) and other militant groups in 2013 and 2014 to keep its cement factory in northern Syria running, long after other French firms had pulled out of the war-torn country.
It is also accused of buying petrol from IS through middlemen, violating an EU embargo on Syria.
Lafarge eventually left Syria in September 2014 after IS seized its plant in Jalabiya, around 150 kilometres (95 miles) northeast of the regional capital .
Eight Lafarge executives, including former CEO Bruno Laffont, have already been charged with financing a terrorist group and/or endangering the lives of the cement-maker's former Syrian staff.
In November 2019, the Court of Appeal in Paris quashed the crimes against humanity charges against the company but upheld the charges of financing terrorism, violating an embargo and endangering the lives of others.
Eleven former employees of Lafarge Cement Syria challenged that decision at the Court of Cassation, France's final court of appeal, with the backing of two NGOs.
Lafarge, which merged in 2015 with Swiss group Holcim, has acknowledged that its Syrian subsidiary paid middlemen to negotiate with armed groups to allow the movement of staff and goods inside the war zone.
But it denies any responsibility for the money winding up in the hands of terrorist groups and has fought to have the case dropped, particularly the crime against humanity charges.
Presenting arguments in the Court of Cassation on June 8, Lafarge's lawyer Patrice Spinosi said the group's only aim had been "the continuation of the cement factory's activity" and that it had no hand in any "concerted plan to eliminate a civilian population".
The government's general counsel has also rejected the charge of complicity in crimes against humanity but recommended trying Lafarge for financing terrorism, saying the company could "not have been unaware of the terrorist nature" of the groups that it paid off.
Lafarge is not the first multinational to be accused of complicity in crimes against humanity over its activity in a country where people suffered serious rights abuses. But such cases have rarely been brought to trial.
Twelve Nigerians took Anglo-Dutch energy giant Shell to court in the US, accusing it of abetting extra-judicial killings, torture, rape and crimes against humanity in the Niger Delta in the 1990s.
The US Supreme Court in 2013 dismissed the case, saying US courts did not have jurisdiction in the matter.