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French bank Credit Agricole is understood to have agreed to pay $800m (£516m) to settle charges it broke US sanctions in Iran and other countries.

The settlement is expected to be announced later this week.

It follows a lengthy investigation of European banks by US authorities into illegal dollar transactions.

In 2013, Royal Bank of Scotland (RBS) was fined $100m by US regulators for violating sanctions against Iran, Sudan, Burma and Cuba.

Credit Agricole stands accused of transferring billions of dollars to accounts held by entities from those same countries between 2003 and 2008.

The bank is paying the fine as part of a so-called deferred prosecution agreement.

The agreement means the bank will not have to plead guilty to any charges as long as it meets certain requirements.

It is understood that some of the bankers responsible for the wrongdoing have already been dismissed from their jobs at the bank.

In August, Credit Agricole set aside $350m in provisions in relation to the case, saying it was at an "advanced stage" in discussions over the alleged sanctions violations and expected to reach a settlement in autumn 2015.

Rival French bank BNP Paribas was ordered to pay a record $8.9bn fine earlier this year for similar alleged violations.

Other European banks including Deutsche Bank, Societe Generale and UniCredit have already said they are co-operating with US investigations into alleged sanctions violations.