The Swiss-French cement company LafargeHolcim should have stopped its operations in war-torn Syria before it did, its chairman said in an interview published Sunday, after three executives were charged with indirectly financing jihadists.

Beat Hess told French daily Le Figaro that the group was going through "a difficult phase" that was "a problem for the company's reputation".

Lafarge is accused of paying the Islamic State group and other militants through a middleman in order to allow the company's factory in Jalabiya, northern Syria, to continue to operate.

It is also suspected of using fake consulting contracts to buy fuel from the Islamic State group, which took control of most of Syria's strategic oil reserves in June 2013.