The Bombay Stock Exchange benchmark Sensex was in red on Friday morning trade. Sensex was down by 402 at 16,457 while NIFTY was down 120 points at 4,884 at 1140 hrs. Sensex tumbled over 451 points while Nifty dropped by 140.50 points in opening trade on hectic selling by funds.Brokers said the selling focus was more on banking and realty stocks after Dubai's debt problems revived concerns about the global financial system and rattled markets across Europe and Asia.