In Business This Week
-- Ousted as chairman, ad man Maurice Saatchi will exit the agency he co-founded.
-- MCI will charge for its 1-800 directory assistance only with customer authorization.
-- IBM Treasurer Frederick Zuckerman unexpectedly announced his retirement.
-- Surprise! Eurotunnel is open 24 hours a day, traffic is up, and so is the stock.EDITED BY KEITH H. HAMMONDS