HSBC and Goldman Sachs accused of rigging platinum and palladium prices

Goldman Sachs and HSBC Holdings are being sued in New York over claims they conspired for eight years to manipulate prices for the precious metals platinum and palladium in what plaintiffs' lawyers say is the first class-action lawsuit of its kind in the United States.

Standard Bank Group and a metals unit of BASF, the world's largest chemical company, are also sued.

The four companies used inside information about client purchases and sale orders to profit from price movements for the metals used in products ranging from jewellery to cars, according to a complaint filed in Manhattan federal court.

The lawsuit by Modern Settings, a jeweller that buys precious metals and derivatives set on their prices, claims the companies "were privy to and shared confidential, non-public information about client purchase and sale orders that allowed them to glean information about the direction" of prices.

Similar lawsuits have been filed this year in Manhattan accusing banks of rigging the benchmark price for gold. The authorities around the world are examining the gold market for signs of wrongdoing.

Regulators tightened scrutiny of benchmarks after uncovering price-rigging in interbank loan rates and currencies.

Silver became the first precious metal to change its traditional pricing procedure in August, and Intercontinental Exchange will run the replacement for the 95-year-old London gold fixing.