Oil was mixed in Asian trade today with sentiment weighed down by a slump in Chinese stocks. New York's main contract, light sweet crude for February delivery, dropped 58 cents to 90 dollars and 96 cents a barrel and Brent North Sea crude for March delivery was up 17 cents at 97 dollars and 60 cents.Optimism about the global economic recovery and interest from bullish investors have pushed crude prices to trade close to 100 dollars a barrel in recent sessions.The rise in global oil prices has also been attributed to a harsh winter hitting Europe and parts of North America, as well as growth in China and other developing nations.