By Claudia Assis
SAN FRANCISCO (MarketWatch) -- Oil futures ended 3% lower on Tuesday, their largest single-day drop since early June, as investors got spooked by falling U.S. consumer sentiment and fears that China's economy may be slowing down. Oil for August delivery lost $2.31, or 3%, to $75.94 a barrel. Natural gas for August delivery retreated 19 cents, or 3.9%, to $4.54 per million British thermal units.
