Britain's financial watchdog said today it had prioritised the worst cases of Libor benchmark interest rate fixing, providing a signal that the largest fines for banks' alleged role in the scandal may already have been levied.
Ten banks and brokerages have paid around $6 billion to date to settle US and European regulatory allegations that they manipulated rates such as Libor (London interbank offered rate), a benchmark against which around $450 trillion of financial products from derivatives to home loans are priced worldwide.
The market has long been braced for similar settlements with Lloyds and Deutsche Bank, which has already been fined by the European Commission over alleged involvement in benchmark interest rate cartels. Industry sources say these two investigations are slowly nearing conclusion.
Martin Wheatley, the chief executive of the Financial Conduct Authority (FCA), said outstanding settlements had been delayed because some investigations had gone beyond Libor and because of the complexities of regulatory coordination.
"There are complications in some of those cases where it has become clear it is not just Libor we are looking at ... and in some cases it's the need to coordinate and cooperate with multiple other agencies," he added.
The FCA is among around 15 authorities around the world to investigate allegations of collusion and price manipulation in the largely unregulated $5.3 trillion-per-day currency market, by far the world's largest.
Banks including Deutsche Bank, Lloyds, Citigroup, Barclays and JP Morgan Chase have fired or suspended - and in some cases reinstated - foreign exchange traders in the row over alleged manipulation.
Mr Wheatley reaffirmed that he hoped to complete the foreign exchange investigation next year, while warning that thecomplexity of the inquiry made timing unpredictable.
"That is certainly our target," he said.
"But I do know that these things are very complicated ... so even 2015 would be a relatively short time-scale given the difficulties and complexities of these cases," he concluded.