Updated from Oct. 18

Shares of

Citrix Systems

(CTXS) - Get Report

plummeted in early Thursday trading a day after the company's third-quarter earnings report fanned concerns about the company's core business.

The stock was recently down 19%, or $6.66, to $28.40.

"I think the major thing that investors didn't like was that they missed on licensing revenue by $8 million," said Goldman Sachs analyst Sarah Friar. But overall revenue was only $3 million shy of estimates, she added.

Citrix said license revenue grew 17% in the quarter, but some analysts on Thursday suggested that result represented a flat year-over-year performance when excluding acquired businesses.

"Weakness in their presentation server business, which is the core of what they do, also spooked people a little," she says. Goldman does not have a banking relationship with Citrix.

"I think sanity will prevail over the next month or so," Friar says. "You just had a very gut reaction tonight."

For the third quarter, Citrix earned $46.6 million, or 25 cents a share, rising from $41 million, or 23 cents a share in the same quarter last year.

Excluding some items, the company earned $64.8 million, or 34 cents a share, up from $52.2 million, or 29 cents a share a year ago. On that basis, the company beat the consensus estimate of 33 cents a share.

Revenue totaled $277.9 million, growing from last year's $226.9 million in the same quarter. That figure fell short of the $280.9 million analysts' target.

Looking ahead to the final quarter of the year, the infrastructure software and services company expects to earn between 27 cents and 28 cents a share.

Excluding amortization of intangibles and some stock-based compensation expenses, the company said it would earn between 37 cents and 38 cents a share, at or above the Thomson First Call consensus of 37 cents.

Sales will range from $307 million to $315 million, vs. the analyst forecast of $308.8 million, Citrix said.

For the full year, the Fort Lauderdale, Fla., company expects to earn $1 to $1.01 a share; the non-GAAP EPS should be in the range of $1.37 to $1.38, better than the average analyst prediction of $1.36.

Revenue, meanwhile, will be between $1.12 billion and $1.128 billion, in line with the $1.12 billion analysts' target.

"We saw strength across our new product portfolio in the third quarter," CEO Mark Templeton said in a statement. He said strong demand continued for the company's application networking and Citrix Online products.