At midday: Stocks flat as home sales disappoint North American stocks were relatively unchanged on Tuesday, as U.S. markets reopened following a three-day weekend and investors digested earnings and a disappointing reading on U.S. home sales. Shortly after noon, the S&P 500 was unchanged, at 1486. The blue-chip Dow Jones industrial average was up 21 points or 0.2 per cent, to 13,670. In Canada, the S&P/TSX composite index was down 6 points or less than 0.1 per cent, to 12,788. U.S. existing home sales fell 1 per cent in December, over the previous month, disappointing expectations for a 1.2 per cent gain. However, economists pointed out that the three-month trend was still up, while sales have risen 12.8 per cent over last year, to a five-year high. Within the S&P 500, telecom stocks and utilities rose 0.6 per cent each. Financials rose 0.4 per cent but technology stocks fell 0.4 per cent. Johnson & Johnson fell 0.6 per cent after it reported operating earnings of $1.19 a share, up from $1.13, beating expectations. However, sales disappointed expectations and the company delivered a weaker than expected forecast for 2013. Dell Inc. rose 2 per cent after CNBC reported that Microsoft Corp. is considering providing up to $3-billion (U.S.) in financing as part of the rumoured buyout of the computer maker. Microsoft shares fell 0.4 per cent. Within Canada's benchmark index, materials rose 0.8 per cent, financials fell 0.1 per cent and energy stocks fell 0.4 per cent. Canadian National Railway Co. fell 1.5 per cent after it reported a fourth-quarter profit of $610-million (Canadian) or $1.41 a share, up from $1.32. The company also boosted its dividend by 15 per cent. Research In Motion Ltd. retreated 0.9 per cent after rallying more than 10 per cent on Monday, when the company's chief executive said in a German publication that the BlackBerry maker was still considering strategic options. Commodities moves slightly higher. Crude oil rose to $96.16 (U.S.) a barrel, up 60 cents and touching its highest level since September. Gold rose to its highest level in a month, hitting $1,694 an ounce, up $4.