An agreement by 10 former WorldCom non-executive directors to pay $18m out of their own pockets to settle a shareholder lawsuit is expected to be a wake-up call for boardrooms around the US.

The agreement, part of a $54m settlement expected soon between former WorldCom directors and the company's shareholders, is the first high-profile case where non-executive directors have faced a personal financial penalty following allegations of failure to look after shareholder interests.