A former Citibank and UBS trader pleaded not guilty Tuesday to eight charges related to rigging the London interbank lending rate, known as LIBOR.

The charges against trader Tom Hayes—who specialized in products pegged to yen-dominated Libor and worked in offices in London and Tokyo—relate to the period August 2006 to September 2010. He is charged with conspiring with employees from other leading institutions, including Deutsche Bank, UBS, JP Morgan Chase, Royal Bank of Scotland Group and HSBC.