Goldman Sachs and agreed to pay $56.5 million to resolve a U.S. class action lawsuit accusing it and other banks of rigging an interest rate benchmark used in the $553 trillion derivatives market. Goldman also agreed to provide lawyers for the plaintiffs evidence including transaction data, documents and witness interviews, which could be used in litigations against the remaining banks, the court papers said.

The proposed settlement came after 7 other banks agreed in May to pay a combined $324 million to resolve the litigation - including JPMorgan Chase, Bank of America, Credit Suisse and Deutsche Bank.

The remaining defendants are BNP Paribas, HSBC Holdings, Morgan Stanley, Nomura Holdings, UBS, Wells Fargo and ICAP.

In the lawsuit, several pension funds and municipalities accused 14 banks, including those that settled, of conspiring to rig the "ISDAfix" benchmark for their own gain from at least 2009 to 2012.

• Companies and investors use ISDAfix to price swaps transactions, commercial real estate mortgages and structured debt securities.
• The lawsuit accused the banks of executing rapid trades before the rate was set each day. It said the banks also caused ICAP, a U.K. brokerage, to delay trades until they moved ISDAfix where they wanted, and post rates that did not reflect market activity.

Separate and apart from this litigation, the CFTC secured settlements of $115 million with Barclays in May 2015 and $250 million with Citigroup in May 2016, related to its own investigation into possible rigging of the ISDAfix benchmark.