The banking giant has been accused by the US Commodity Future Trading Commission (CFTC) of attempting to manipulate the US Dollar International Swaps and Derivatives Association Fix (ISDAFIX) – a global benchmark reference in a range of interest rate products.
The news comes a week after RBS set aside another $3.8bn (£3.1bn) ahead of an expected fine from US authorities to cover a potential settlement over its alleged role in the mis-selling of toxic mortgage-backed securities before the financial crisis.
Aitan Goelman, director of the CFTC’s division of enforcement, said it was the fourth time the organisation had taken enforcement action over attempts to manipulate the ISDAFIX.
“These actions, and the CFTC’s previous cases against those who sought to corrupt the Libor and foreign exchange benchmark rates, make clear that the Commission takes very seriously its role in ensuring the integrity of any and all benchmarks used in our markets,” he added.
Ross McEwan, RBS chief executive, strongly condemned the traders’ actions and said it was an example of “past misconduct”.
He said: “These findings make for uncomfortable reading and we have already taken significant steps to make sure this kind of behaviour cannot happen again.
“The culture and structure of RBS has changed dramatically in recent years; I’m pleased we can put this issue behind us and concentrate on the important job of building a bank that is fully focused on the best interests of its customers.”