Laurent Fabius, France's foreign minister, has dismissed as unreasonable a reported fine of $10bn that the US is seeking to place on bank BNP Paribas, and warned that it could threaten a free trade agreement between the US and Europe.

BNP Paribas, France's largest bank, set aside $1.1bn last year after the US began investigating it for alleged sanctions violations, but this spring said the fines could be "far in excess", the Reuters news agency reported.

Its share price slumped last week after the Wall Street Journal that reported the fine could be $10bn.

"The sanction has to be proportional and reasonable. These amounts are not reasonable" Fabius told France 2 television on Tuesday.

He said the fine could have a negative effect on negotiations on a free-trade agreement between the EU and the US,the fifth round of which was held in Washington on May 19, the AFP news agency reported.

"This trade partnership can be established only on a basis of reciprocity. But here, we would have the example of an unjust and unilateral decision", Fabius said.

Meanwhile, the New York Times newspaper reported that Christian Noyer, governor of the Bank of France, had visited top US officials on the case in New York last week to warn that such a fine, equivalent to 7.4 billion euros, could have grave effects on the financial system.

President Francois Hollande has also recently raised concerns about a plea deal with the White House, the daily said.

Source: Agencies