The beard of WorldCom Inc’s genial boss Bernard Ebbers is likely to be as white as Santa Claus by the time the take-over battle for MCI Corp is over. The Justice Department has just demanded additional information on its bid in a move which signals close examination of every aspect of the deal. While WorldCom expressed hopes that the deal could be completed by the first quarter of next year, those with a less optimistic view of the speed with which official bodies operate, forecast that it may be a year before anything is decided.