The US Commodity Futures Trading Commission (CFTC) said it ordered the Royal Bank of Scotland to pay an $85 million civil monetary penalty as part of a settlement reached on Friday to settle charges RBS tried to manipulate a key foreign exchange swaps benchmark rate.

The CFTC said it found that over a five-year period from January 2007 through March 2012 RBS, through the acts of multiple traders, attempted to manipulate the US Dollar International Swaps and Derivatives Association Fix (USD ISDAFIX), a global benchmark reference in a range of interest rate products.

“RBS engaged in the unlawful conduct in order to benefit certain derivatives positions it held that were priced or valued off of the USD ISDAFIX benchmark,” said the CFTC.

“People around the world rely on benchmark rates such as ISDAFIX,” said Aitan Goelman, director of the CFTC’s division of enforcement.

“This is our fourth enforcement action relating to 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.”

RBS CEO Ross McEwan said in a statement: “This is an example of past misconduct that has no place at RBS.

“These findings make for uncomfortable reading and we have already taken significant steps to make sure this kind of behaviour cannot happen again.”