Updated from 9:48 a.m. EST

Symantec

(SYMC) - Get Report

surged as much as 8% Thursday morning after posting a strong third quarter and raising guidance for the full fiscal year.

Shares of Symantec recently gained $1.20, or 3.2%, to $39.05.

On Wednesday evening, Symantec reported a 31% climb in fiscal third-quarter results, surpassing earnings and revenue expectations once again on stronger-than-expected consumer sales. The Cupertino, Calif.-based security software company also said fourth-quarter results should beat current estimates.

But despite that strong showing, some analysts expressed disappointment with the company's sales to businesses.

Symantec's enterprise security business benefited from exchange rates, Piper Jaffray analyst Gene Munster said in a note Thursday. But he was surprised that enterprise security sales of $186.7 million fell short of his $202 million estimate.

Retail box sales combined with favorable exchange rates drove the upside in the consumer business, Munster said. He maintained his market perform rating on Symantec, reiterating concerns that the entry of giant

Microsoft

(MSFT) - Get Report

into the antivirus market will eventually weigh on Symantec shares. His firm hasn't done any banking with Symantec or Microsoft.

Symantec reported net income under generally accepted accounting principles of $111.5 million, or 32 cents a share in its third quarter, which ended Jan. 2. That compared to net income of $71.7 million, or 22 cents a share on a split-adjusted basis, in the same period a year earlier.

Excluding charges, which some analysts argued have become part of Symantec's ongoing cost of doing business, Symantec said it earned pro forma net income of $119.7 million, or 34 cents a share, in the third quarter, compared to pro forma net income of $76.7 million, or 24 cents a share, a year earlier.

Revenue rose 31% to $493.9 million from $375.6 million a year earlier and up 15% sequentially from $428.7 million in the second quarter.

Wall Street estimates gathered by Thomson First Call forecast Symantec would earn pro forma net income of 29 cents a share on $460.2 million in revenue in the third quarter. The company's guidance called for presplit earnings of 52 cents a share on $440 million to $460 million in revenue in the third quarter.

Symantec, whose consumer business has helped the company consistently beat estimates, expects fiscal fourth-quarter revenue to range from $500 million and $520 million, with pro forma earnings at 32 cents a share and GAAP earnings at 30 cents a share, based on the midpoint of revenue guidance. Analysts' forecasts call for revenue of $471.6 million and pro forma earnings at 29 cents a share.

For the full fiscal year ending April 2, Symantec raised its guidance. The company said it expects revenue to be $1.82 billion, up from its prior forecast of $1.73 billion, with GAAP earnings up 8 cents from prior guidance to $1.03 a share and pro forma earnings up 9 cents to $1.14 a share. Analyst estimates call for revenue of $1.75 billion and pro forma earnings at $1.07 a share.

Symantec also offered guidance for fiscal 2005, which includes its ON Technology acquisition scheduled to close in February. Revenue will range from $2.15 billion to $2.20 billion, GAAP earnings will be $1.21 a share and pro forma earnings will be $1.31, at the midpoint of the revenue range. Analysts' estimates call for EPS of $1.20 on revenue of $2 billion.

"It looks like they blew out across the board. Everything was pretty impressive," said Janney Montgomery Scott analyst Joel Fishbein, who has a buy rating on Symantec. "It was not just consumer." (His firm hasn't banked with Symantec.)

However, in a note Thursday, Fishbein joined Munster in acknowledging that enterprise security business sales grew below his estimate, which was sitting at $196 million.

Still, Symantec's enterprise security business did grow 17% year-over-year and represented 38% of total revenue. Its consumer business sales soared a whopping 55% from a year ago to represent 49% of total revenue.

The key concern with enterprise security sales is a deceleration in year-over-year growth to 17% from 25% in the previous quarter, noted Legg Mason analyst Todd Weller. "Overall, Symantec's enterprise security performance was disappointing, but we believe that the hiring of a new head of sales could help to improve the situation," Weller wrote in a note Thursday. Still, he reiterated his buy rating on Symantec, saying it's the best positioned company in the security space. (His firm hasn't done any banking business with Symantec.)

In the past, Symantec management has cautioned that the growth in consumer numbers in particular will taper off, though quarter after quarter that fails to happen -- much to the glee of investors.

With commanding market share in the consumer market and ongoing concerns about security, Symantec is likely to continue to benefit at least for the short term, said Lehman Brothers analyst Israel Hernandez, who has an overweight rating on Symantec.

"They are not going to be able to grow at the rates they have been growing forever, clearly," Hernandez said. But "it's sustainable over the near term." (His firm has not done banking business with Symantec.)