BONDHOLDERS in WorldCom Inc.’s subsidiaries could be big losers if the judge presiding over the largest U.S. corporate bankruptcy decides the company’s assets cannot be separated.

Lawyers for the bondholders of the MCI Group subsidiary have argued that their clients have structural seniority to the other bondholder groups, even though they hold just over $3 billion of WorldCom’s $28 billion in bond debt, because MCI owns the most valuable assets.