Although oil dipped briefly below $45 per barrel during the session, two days of falling prices weren't enough for cautious investors to get back into the market, despite very attractive prices.

Investors were concerned that oil prices, which topped $49 per barrel late last week but closed down 84 cents at $45.21 on the New York Mercantile Exchange, could advance again.

"Without any real big economic or geopolitical news here, the market's keying off of oil," said Jay Suskind, head trader at Ryan Beck & Co. "But we're in the dog days of August here, so there's just not going to be a lot of volume or conviction here."

Many investors were also making few trades leading up to the Republican National Convention, analysts said. They were also holding back as they awaited the government's employment report for August, due at the end of next week.

According to preliminary calculations, the Dow Jones industrial average was up 25.58, or 0.2 percent, at 10,098.63.

Broader stock indicators were narrowly mixed. The Standard & Poor's 500 index was up 0.51, or 0 percent, at 1,096.19, and the tech-focused Nasdaq composite index lost 1.81, or 0.1 percent, to 1,836.89.

An increase in stock options granted by Cisco Systems Inc. caused UBS to lower its price target for the network equipment maker by $1 per share. Cisco slid 21 cents to $18.97. Tech shares have been closely watched as they begin more thorough accounting of their stock options.

The market had little reaction to the National Association of Realtors' existing home sales report, which showed that 6.72 million units changed hands in July, down 2.9 percent from June and less than economists had expected.

Echoes of the last bear market have made investors very cautious, especially in low-volume sessions like today's. "Nobody really believes in growth. The market is much more sensitive to negative news," said Richard Driehaus, chief investment officer of Driehaus Capital Management in Chicago

Part of the Dow's gains came from Caterpillar, which rose $1.10 to $73.15 after Goldman Sachs upgraded the stock to "outperform" from "in-line/neutral," citing strong profit performance and an attractive share price.

Advancing issues outnumbered decliners by about 5 to 4 on the New York Stock Exchange, where volume came to 1.02 billion shares, equaling yesterday's light volume.

The Russell 2000 index of smaller companies was up 1.54, or 0.3 percent, at 545.01.