Stocks pulled back from earlier gains after two separate reads on manufacturing activity in the U.S. showed a worrying slowdown trend. Modest gains were enough to push the Dow into positive territory for the year. Manufacturing activity slipped into a contraction in November, bottoming out at its lowest level since mid-2009. New orders and exports showed weakness over the month, according to the ISM Manufacturing Index. Auto sales at Ford (F) and General Motors (GM) climbed, though at a slower-than-expected pace. Ford sales edged 0.4% higher, well below estimates of 3.2% growth. GM posted a 1.5% increase in monthly sales, half of what analysts had expected.