NEW YORK (CNN/Money) - After markets closed little changed Monday, U.S. stock investors Tuesday will be focused on the release of a slew of influential quarterly profit reports, starting with No. 1 chipmaker Intel.

On Tuesday after the close of trade, Intel (INTC: down $0.04 to $17.38, Research, Estimates) is expected to report a fourth-quarter profit of 14 cents a share, a penny less than it earned in the year-earlier quarter.

Previewing the company's results in an early note Monday, Salomon Smith Barney raised its estimates for fourth-quarter earnings per share and revenue targets, as well as 2003 earnings per share targets. The firm said that its previous estimates were too conservative and its recent checks of Intel's business show that pricing in Europe and Asia may have picked up steam.

The stock is the first of a number of heavily weighted and influential technology stocks due to report quarterly reports this week. The list also includes IBM, Microsoft and Sun Microsystems.

The Dow Jones industrial average (up 1.09 to 8785.98, Charts), the Nasdaq composite (down 1.68 to 1446.04, Charts) and the S&P 500 index (down 1.31 to 926.26, Charts) all closed little changed Monday, after having drifted on both sides of breakeven throughout the session.

The news of AOL Chairman Steve Case's resignation and the announcement that OPEC was boosting oil production had preoccupied investors in the early going.

But as the day progressed, investors' attention turned to the upcoming quarterly releases.

"This is a very important week in the market," said Brian Finnerty, managing director at Melhado, Flynn & Associates. "It's all about earnings, earnings, earnings."

After the close of trade Monday, memory chipmaker Rambus (RMBS: up $0.22 to $8.40, Research, Estimates) reported a fiscal first-quarter profit of 6 cents a share, a penny better than expected and in line with results one year earlier.

Tuesday brings Intel, then after the close of trade Wednesday, Yahoo! (YHOO: down $0.33 to $19.67, Research, Estimates) is expected to report a fourth-quarter profit of 6 cents per share, the same as a year earlier.

But Thursday is by far the biggest day of the week.

After the close of trade Thursday, IBM (IBM: down $0.17 to $87.51, Research, Estimates) is expected to report a profit of $1.30 a share, down from the $1.46 earned a year earlier, while Microsoft (MSFT: up $0.42 to $56.34, Research, Estimates) is expected to have earned 46 cents in its fiscal second quarter, down from the 49 cents it earned a year earlier.

On Monday, Microsoft agreed to pay up to $1.1 billion to California computer users to settle class action lawsuits that alleged the software leader unfairly used its monopoly to hike prices in California. Similar suits are still active in 16 other states and the District of Columbia.

Sun Microsystems (SUNW: unchanged at $3.77, Research, Estimates) also reports after the bell Thursday. It is forecast to have lost 2 cents a share in its fiscal second quarter, after losing 3 cents in the year-earlier period. eBay (EBAY: up $0.61 to $73.97, Research, Estimates) is expected to have earned 24 cents in its first quarter, up from the 14 cents earned a year earlier.

"Tuesday's Intel, Wednesday has a few good ones and then Thursday is IBM, Microsoft and a whole bunch of them," said Melhado, Flynn's Finnerty. "This is the week we've got to prove ourselves."

Steve Case handed in his resignation, effective in May, late Sunday, as chairman of AOL Time Warner (AOL: up $0.15 to $15.03, Research, Estimates), this site's parent company. Case, a co-founder of AOL and one of the chief engineers behind the 2001 merger of the online service provider with Time Warner, had been blamed for the stock's downhill performance, which has largely been attributed to weakness at the AOL unit. The company has named no successor to Case.

In addition, on Monday, CNN Chairman Walter Isaacson said he is stepping down.

AOL stock had rallied at the open, before easing back, with its gains relatively limited as investors saw Case's departure as only a detail in what is likely be a major turnaround strategy at AOL Time Warner.

The day's other corporate news was largely dictated by analyst commentary.

Motorola (MOT: down $0.48 to $9.45, Research, Estimates) shares slid after Credit Suisse First Boston downgraded it to "underweight" from "neutral" and cut its price target to $8 a share from $11, saying the fundamental risks outweigh the potential rewards at the current valuation. The stock was one of many techs pressuring the market.

Leading PC maker Dell (DELL: down $1.17 to $25.98, Research, Estimates) slid after J.P. Morgan cut its rating on the stock to "neutral" from "overweight," citing pricing competition from Dell's rivals.

Among the Dow stocks, Johnson & Johnson (JNJ: down $1.16 to $56.04, Research, Estimates) declined after brokerage firm Thomas Weisel Partners downgraded the stock to "attractive" from "buy," citing an increasingly tough 2003 outlook for the company.

A weekend decision by OPEC to boost crude production by 7 percent initially provided some support to the market, with oil prices dropping. But prices resumed their upward trend in afternoon trade.

Oil prices had been rising under the pressure of a threat of war between the United States and Iraq and an oilworker strike in Venezuela. Expensive oil could have thrown cold water on an already fragile economic recovery. On Monday, light crude oil futures rose 58 cents to $32.26 a barrel in New York.

Bonds were modestly higher, with the 10-year note gaining 3/32 of a point in price, pushing the yield down to 4.12 percent from 4.14 percent late Friday. Bond prices and yields move in opposite directions. The dollar gained a little against the euro, but was weaker against the yen.

Gold gained 20 cents to trade at $355.10 an ounce in New York.

Overseas, European markets closed mixed, while Asian-Pacific shares closed higher Monday, with the exception of the market in Tokyo, which was closed for the Coming of Age holiday.

Market breadth was mixed. On both the New York Stock Exchange and Nasdaq composite, losers and winners were nearly evenly split. On the NYSE, almost 1.36 billion shares changed hands. On the Nasdaq, 1.56 billion shares traded.