NEW YORK (CNN/Money) - U.S. stocks opened higher Friday as buyers came back after a tough week for stocks on a handful of broker upgrades.

The Dow Jones industrial average (up 4.22 to 10,554.93, Charts) and the broader Standard & Poor's 500 (down 1.22 to 1,219.02, Charts) rose 0.3 percent and the tech-heavy Nasdaq composite (down 9.07 to 2,136.08, Charts) edged up 0.1 percent.

Volume was light and market breadth was negative. Winners beat losers on the New York Stock Exchange two to one as 80 million shares changed hands. Advancers narrowly topped advancers on the Nasdaq as 99 million shares were traded.

Trading moves are often exaggerated when volume is low, allowing a handful of stocks to push major gauges into positive territory.

UBS upgraded Dow component Coca-Cola (Research) to a "buy" recommendation from "neutral," sending shares higher at the start of the day.

Other upgraded stocks include financial services company Mellon Financial (unchanged at $31.11, Research), teen retailer Aeropostale (unchanged at $23.75, Research), auto parts company Delphi (unchanged at $5.92, Research) and mining company BHP Billiton (unchanged at $16.94, Research).

Sanofi-Aventis (unchanged at $42.96, Research) also moved higher on news that a Phase III study reported in the Journal of Clinical Oncology showed that its Taxotere was more effective in helping advanced breast cancer patients than Bristol-Myers' (unchanged at $24.88, Research) paclitaxel.

And Northwest Airlines (Research) and leaders of its mechanics union are set to meet Friday in an effort to hammer out a contract before a midnight deadline. The union is allowed to go on strike at 12:01 a.m. ET Saturday, but a handful of brokerages have said the company has priced in the cots of a strike.

Analysts were skeptical that the early morning strength would continue, predicting a day of choppy trading.

On the opposite side of the ledger, clothing retailer Gap (Research) posted improved profits that topped forecasts, but trimmed its 2005 earnings outlook, sending shares lower.

And fellow retailer Ann Taylor (unchanged at $25.04, Research) said quarterly profit fell because it was forced to mark down prices to clear out summer inventory.

The retail sector has taken a beating all week, leading economists to speculate that high fuel prices are finally taking a bite out of consumer spending.

Oil prices were up again following a narrow move in Thursday trading.

The September light crude futures contract for NYMEX gained $1.12 to $64.39 a barrel in electronic trading.

Major markets in Asia closed mostly lower Friday. Major European markets were mostly higher in midday trading.

Treasury prices were slightly lower, lifting the yield on the 10-year note to 4.23 percent from 4.20 late Thursday. The dollar drifted against the euro and the yen.

Comex gold lost 90 cents to $443.80.

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