Wall Street ended an erratic session with a big advance today as investors uneasy about the economy were reassured by solid earnings from blue chip names including Apple Inc. and American Express Co. The Dow Jones industrial average rose more than 100 points.

Technology stocks were among the biggest gainers after Apple surpassed analysts’ expectations with a 67% jump in fiscal fourth-quarter profit on strong sales of Macintosh computers, iPods, and iPhones. Two component companies of the Dow Jones industrial average — American Express, one of the largest credit card companies, and chemicals maker DuPont Co. — posted better-than-expected profit gains as well.

But comments from the CEO of DuPont, Charles Holliday Jr., that the company doesn’t expect a recovery in the housing market next year reminded investors of the still uneasy forecasts for the economy. Holliday’s remarks helped pull the major indexes down from their session highs before the indicators rebounded in afternoon trading.

“Housing is obviously still a big concern, and the question is how much does it spill over into the rest of the economy,” an economist and market analyst for Chicago-based Barrington Research, Alexander Paris, said. “I think the trend for the market is down unless investors see something positive, and the market drifts back up again.”

He said investors were also adjusting their positions ahead of key housing data this week. On Thursday, the National Association of Realtors will release its existing home sales report, while the Commerce Department reports new home sales a day later.

According to preliminary calculations, the Dow rose 109.26, or 0.81%, to 13,676.23.