The stock closed down $5.13, or almost 8 percent, to $61.81. Earlier in the day, shares touched $51.50, a new 52-week low.
Qualcomm makes cell phone chipsets and system software, then licenses that technology to others. Its code division multiple access technology, or CDMA, is widely used by wireless companies in the United States.
The Financial Times reported Friday that Qualcomm's third-generation, or 3G, mobile services would take two more years to hit European markets.
The paper quoted CEO Irwin Jacobs as saying that 3G services now in development would not be "commercially viable" until late 2004 or early 2005.
The report comes amid growing concerns that the 3G technology, which cell phone technology companies are counting on to boost sales, will not see the demand expected of it.
3G technology will allow wireless devices to receive music, video and pictures, and incorporate global positioning system satellite receivers to allow them to display localized content based on the customer's exact location.
But the costs in upgrading to 3G may have scared off some carriers, particularly at a time when the overall financial picture for telecom companies is weak.
"Although these carriers eventually stand to reap the benefits of a 3G network, there are mixed signals floating in the air pertaining to the timing of the infrastructure upgrades," wrote Deutsche Banc Alex Brown analyst Brian Modoff in a research note.
Modoff downgraded Qualcomm, along with wireless companies Powerwave, Tekelec, DMC Stratex Networks, Stanford Microdevices and Airspan, from "strong buy" to "buy."
Modoff said discussions with carriers and equipment suppliers at the GSM Congress in Cannes were a factor in the downgrades.
"We believe traffic demands and the competitive environment will drive carriers to continue with buildout and upgrade plans. However, we are witnessing reduced spending plans, and perhaps a bit of uncertainty on their part regarding how rapidly this buildout will continue," Modoff wrote in a research note.
There have been other signs of problems. Last week, telecommunications-equipment maker Nortel Networks, the world's biggest supplier of fiber-optic telecommunications gear, said it would report a first-quarter loss and lowered its revenue growth expectations for the year.