The Sensex at the Bombay Stock Exchange was trading 45 points down at 19,850 points in afternoon deals today.It gained 42 points in early trade today, on buying in stocks of consumer durables, oil and gas and capital goods, amid a firming Asian trend. The 30-share barometer had lost 110 points in the previous session.The Nifty at the National Stock Exchange was trading 16 points down at 6,018 points a shortwhile ago.