A quarterly profit increase of 10 percent at Texas Instruments disappointed analysts and sent shares tumbling in premarket trade.
The company, which makes cell phones, televisions, computer chips and a variety of other products, fell well short of forecasts, sending the stock price down 6.6 percent before the opening bell.
"It has to do with our concerns with regards to the market share loss at Sony Ericsson specifically this quarter," Jefferies semiconductor analyst John Lau told CNBC, "and our additional concerns of their continuing to lose market share at Nokia next year."
TI forecast fourth-quarter revenue of $3.4 billion to $3.68 billion, compared with the average analyst view of $3.7 billion, according to Reuters Estimates.
Nokia has been Texas Instruments' largest wireless customer.
Lau is not alone in his concerns. Credit Suisse, JP Morgan, Lehman and UBS have all cut their ratings on the company.
"We were very, very surprised by the outlook given for the December quarter," Lau said. "The impact of the diversification by Sony Ericsson hit them harder than we thought...they're off by over a hundred million dollars."
Other analysts were also taken by surprise. "People didn't think it was going to be that significant," Charter Equity Research analyst John Dryden told Reuters.
The diversification has been particularly hard on Texas Instruments because of rising costs.