NEW YORK (CNN/Money) - Technology stocks clung to gains Thursday as investors hunted down bargains after the Nasdaq's 2.5 percent sell-off the previous session, but traders became leery that Friday's U.S. employment report could come out weaker than expected.

The tech-laced Nasdaq index finished up 5.42 points, or 0.27 percent, at 2,019.56. Advancers outnumbered decliners five to four on Nasdaq.

Medtronic (MDT: down $4.75 to $47.25, Research, Estimates) shares tumbled from near-record levels Thursday, leading its peers lower after the medical device maker indicated that growth in a key unit has slowed in recent weeks.

Late Wednesday, Medtronic, whose shares fell by as much as 10 percent in early trading, reduced its revenue forecast for its fiscal third quarter to $2.195 billion from a December projection of $2.230 billion.

Medtronic, the world's largest medical device maker, said growth in the market for implantable cardioverter defibrillators (ICDs), devices that slow down a racing heart beat, had slowed in recent weeks to about 20 percent. Many on Wall Street were predicting growth of 25 percent.

Shares of fellow ICD makers Guidant (GDT: down $0.25 to $62.35, Research, Estimates) and St. Jude Medical (STJ: up $1.53 to $72.94, Research, Estimates) slumped as well.

Medtronic is scheduled to release its full quarterly results on Feb. 11.

In other technology-related news, Level 3 Communications (LVLT: Research, Estimates), a high-speed communications network operator, posted a smaller quarterly loss, and said it expects its core communications sales to decline this year, sending its shares down more than 12 percent.

The company said America Online, its largest managed-modem customer, recently said it planned to cut purchases of dial-up Internet capacity. That loss, as well as overall declines in the sector, would cut annual revenue by as much as $150 million, and weigh on free cash flow, Level 3 said.

American Online and CNN/Money are both owned by Time Warner Inc. (TWX: Research, Estimates)

RF Micro Devices (RFMD: up $0.55 to $9.28, Research, Estimates) reiterated that it expects sales this year to exceed the growth rate of the overall wireless telephone market.

The news sent the wireless chip maker's shares more than 6 percent higher in heavy trading on the Nasdaq.

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RF Micro is considered a bellwether for the wireless industry because its products appear in the wireless phones of most of the world's top manufacturers, including Finland's Nokia (NOK: down $0.03 to $20.47, Research, Estimates), Motorola Inc. (MOT: up $0.23 to $16.25, Research, Estimates) of the U.S. and South Korea's Samsung Electronics Co. Ltd.

Among some tech heavyweights, Cisco Systems (CSCO: Research, Estimates) stock fell 1.1 percent to $23.82, while shares of Microsoft (MSFT: Research, Estimates) were down 0.2 percent at $26.96.

Intel (INTC: Research, Estimates) lost 0.3 percent at $29.92, but Sun Microsystems (SUNW: Research, Estimates) rose 3.7 percent to $5.31. The four tech giants are some of the most actively traded stocks on Nasdaq.

International Business Machines (IBM: Research, Estimates) fell 1.3 percent to $98.86 on the New York Stock Exchange.

Investors will likely focus on Friday's employment report for January, with economists expecting some 150,000 new non-farm jobs created, encouraging the view that the U.S. economy's recovery is finally starting to create jobs.  

-- from staff and wire reports