WASHINGTON (MarketWatch) - U.S. factory orders dropped 2.1% in October in line with the forecast of economists polled by MarketWatch. Orders for September were also revised to show a 0.2% gain instead of a 0.7%, the government said Thursday. Although manufacturers are still increasing production, business investment has softened since midsummer after a year and a half of strong gains, potentially limiting future U.S. economic growth.