Source: Sharecast
The plaintiffs had accused the French bank of enabling human rights abuses by providing banking services to Omar al-Bashir, the former president of Sudan, in violation of US sanctions.
The New York federal court agreed, and on Monday found BNP liable for more than $20m in damages.
Lawyers for the three plaintiffs said the verdict opened the door for more than 20,000 refugees in the US to seek damages from BNP.
As at 1300 BST, the stock had tumbled 9% in Paris.
BNP, France’s biggest lender, said it would appeal.
"There is no doubt whatsoever that the bank will fight this case, and use all recourses available to it," it said. "This result is clearly wrong and ignores important evidence the bank was not permitted to introduce.
"Furthermore, this verdict is specific to these three plaintiffs and should not have broader application. Any attempt to extrapolate is necessarily wrong as is any speculation regarding a potential settlement."
Al-Bashir overthrew the elected government of Sudan in 1989. He went on to serve as president until 2019, when he was ousted in a military coup.
He has been accused of genocide by the International Criminal Court and was sentenced to two years in prison in Sudan on corruption charges.
