Barclays has suspended six traders following an internal investigation into manipulating the foreign exchange market.The traders were suspended yesterday and include workers from across the bank's operations, sources told the Financial Times. Chris Ashton, who oversees the bank's voice-spot trading across the globe, was among those suspended but he remains active on the UK financial regulator's list of authorised traders. Jack Murray, based in Tokyo, and Mark Clark, based in London, were also suspended. Authorities in the UK, the US and Switzerland, among other countries, have launched preliminary investigations into the world's biggest banks over rigging the $5.3tn currency market.UBS, Deutsche Bank, JPMorgan and Barclays have all been asked for information. Barclays has declined to comment on the claims. Shares fell 1.80% to 258.85p at 13:38 on Friday.RD