The examiner behind the official report into WorldCom's collapse has urged the company to retrieve the $106m (€84m) it paid Citigroup's Salomon Smith Barney unit in investment banking fees.

Richard Thornburgh, former US attorney general and author of the report, has concluded that WorldCom should sue Citigroup and Bernie Ebbers, former WorldCom chief executive, for their roles in the demise of WorldCom.