FINMA's director Mark Branson said investigations had shown the problems at UBS went beyond currency trading. "The behaviour patterns in precious metals were somewhat similar to the behaviour patterns in foreign exchange," he said in a conference call with journalists.

As UBS has precious metals and foreign exchange desks under combined leadership, it was not surprising to find similar behaviour, he said. "But we have also seen a clear attempt to manipulate fixes in the precious metal market," added Branson, himself a former UBS banker.

FINMA said in its report that it had seen repeated "front running" - trading on advance information not available to clients - on the now defunct once-daily silver fix.