Updated from 4:21 a.m. EST

Virtualization trailblazer

VMware

(VMW) - Get Report

beat analyst

revenue estimates

with its fourth-quarter results Monday, but issued weaker than expected first-quarter guidance, citing the ongoing climate of economic uncertainty.

VMware reported fourth-quarter revenue of $515 million, a 25% hike on the prior year's quarter, beating consensus estimates of $512.34 million. For fiscal 2008, the Palo Alto, Calif.-based firm's revenues were $1.9 billion, an increase of 42%, which came in just above analyst estimates.

Excluding items, VMware's reported fourth-quarter earnings of 36 cents a share on net income of $142 million, compared to 26 cents a share and net income of $103 million in the same period last year. Analysts had predicted earnings of 26 cents a share.

VMware, which is majority-owned by storage giant

EMC

(EMC)

, said that its results were boosted by its license and services revenues, which grew 30% and 67% year over year, to reach, respectively, $1.2 billion and $703 million.

"VMware delivered a solid fourth quarter to cap off a successful 2008 - we have been executing well in a difficult economy," said Paul Maritz, the VMware CEO, in a statement. The firm is also making progress around its three key initiatives of data center and desktop virtualization and

cloud computing

, he added.

Virtualization software, which lets multiple operating systems run in the same computer, has been one of the fastest-growing technologies of recent years, thanks largely to VMware's efforts. Touting its technology as a way for users to streamline their hardware infrastructures the software company has risen from relative obscurity to more than 130,000 customers in just over a decade.

For the first quarter of fiscal 2009, however, VMware issued first-quarter guidance of $475 million, well below analyst estimates of $496.53 million.

The virtualization specialist, which competes with

Microsoft

(MSFT) - Get Report

and

Citrix

(CTXS) - Get Report

, also said that it would not provide revenue guidance for fiscal 2009. "Current uncertainty in global economic conditions makes it particularly difficult to predict product demand and other related matters," it said, in a statement.

VMware's shares slipped 30 cents, or 1.36%, to $21.80, in extended trading.