Shares of France's biggest bank BNP Paribas (BNP) tumbled in early trading on Friday after reports said the U.S. authorities would seek a penalty of 10 billion U.S. dollars from BNP over alleged dealings with countries subject to sanctions.
Risks related to a U.S. probe tainted transactions on the stock exchange NYSE Euronext Paris, leading the CAC 40 index losing 0.54 percent to 4.506 points at 15:47 local time (1347 GMT).
BNP saw its shares decreasing by 4.14 percent to 50.470 euros (68.75 U.S. dollars), its worst performance in eight months.
In a report of the Wall Street Journal released on Thursday, Justice Department authorities of the United States were said to ask BNP to pay 10 billion U.S. dollars over alleged dealings with countries subject to sanctions such as Iran, Cuba and Sudan.
"A fine of 10 billion USD would have a negative impact of 2.5 euros per share of the bank's estimated value and could force it to increase capital or change its bosses," Erin Davi, analyst from investment research firm Morningstar wrote in a note.
BNP officials were not immediately available to comment. (1 euro = 1.36 U.S. dollars)