NEW YORK ( TheStreet) -- Cisco ( CSCO) experienced a volatile after-hours session on Wednesday as shares of the networking giant first rallied on the heels of a better than expected quarterly report then quickly turned lower during the company's conference call as executives offered up underwhelming outlook.

The Dow component posted an adjusted profit of $2.35 billion, or 42 cents a share, for its fiscal third quarter ended in April on revenue of $10.87 billion, topping the average estimate of analysts polled by Thomson Reuters for earnings of 37 cents a share on revenue of $10.85 billion.



The shares initially surged in late trades, running as much as 4.6% higher to $18.59, before reversing course and sliding into negative territory as the company said it expects adjusted earnings of 37 to 39 cents a share in its fiscal fourth quarter ending in July, below the current consensus view of 41 cents. Revenue is projected to be flat to up 2% year-over-year for the quarter, also a disappointment.

>>>Cisco Shares Wobble: Live Blog

The stock was last quoted at $17.25, down 3%, on volume of nearly 25 million shares, according to Nasdaq.com.

The quick sell-off underscores the market's frustration with Cisco and John Chambers, its chief executive officer, as the company has made a habit of giving below-consensus guidance in recent quarters. When the company reported its fiscal second-quarter results on Feb. 9, the weak forecast for the third quarter sent shares more than 10% lower in after-hours trades.

The company had stirred up some optimism ahead of this latest report, however, with Chambers having acknowledged the need for changes, and Cisco taking steps to restructure and streamline operations. Based on Wednesday's regular session close at $17.78, the stock had bounced more than 7% since plumbing a 52-week low of $16.52 on April 19.

Clearwire

Shares of Clearwire ( CLWR) slumped in late trades after Intel ( INTC) disclosed plans to sell 10 million shares of Clearwire Class A common stock in the open market.

The stock was last quoted at $4.52, down 4.4%, on volume of less than 80,000. Based on Wednesday's regular session close at $4.73, the shares are down 8% since the start of 2011 and 41% in the past year.

Clearwire, a Kirkland, Wash.-based provider of wireless broadband services, said in the regulatory filing with the Securities and Exchange Commission that the selling will begin on Friday, and that Intel expects the divestiture is part of the periodic re-balancing of its equity portfolio and that it anticipates the sales will yield tax benefits.

Dynavox

Dynavox ( DVOX) was a standout gainer in late trades after its fiscal third-quarter report topped Wall Street's expectations.

The Pittsburgh-based maker of communication and education products for people with learning disabilities posted an adjusted pro forma profit of $2.6 million, or 9 cents a share, in the three months ended April 1, on sales of $28.7 million.

The average estimate of analysts polled by Thomson Reuters was for earnings of 6 cents a share on revenue of $25 million.

""In spite of the ongoing macroeconomic challenges, during the third quarter we saw some signs of improvements and our consolidated top line was roughly equal to the last year," said Ed Donnelly, the company's CEO, in a press release. "Sales trends across both devices and software provide validation of our efforts to adapt to the environment as well as the fact that the demand for our products and services remains intact."

Donnelly added that the company is "encouraged" by the sequential increase in its U.S. device business.

Dynavox also forecast adjusted pro forma earnings of 21 to 27 cents a share for fiscal 2011 with adjusted EBITDA earnings before interest, taxes, depreciation and amortization of between $19 million to $23 million. The company now sees a net sales decline of 6% to 8% for the year, an improvement from a prior projection for a drop of 10% to 15%.

Other stocks moving in late trades included Zipcar ( ZIP), which ticked lower after the vehicle sharing services provider posted a first-quarter loss of $6.1 million, or 95 cents a share, wider than a year-ago equivalent loss of $5.3 million; and Sina Corp. ( SINA), which gained 2% to $122.50 on volume of more than 500,000 after the Chinese online media company forecast healthy sequential growth in its non-GAAP revenue to $112 million to $115 million in its fiscal second quarter.

-- Written by Michael Baron in New York.

>To contact the writer of this article, click here: Michael Baron.

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Disclosure: TheStreet's editorial policy prohibits staff editors, reporters and analysts from holding positions in any individual stocks.

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