By Sam Oliver

Published: 04:00 PM EST

The presence of Apple products in the enterprise is much more pervasive and complex than previously thought, according to new study, which reveals the Macs and the Mac OS X operating system are now gaining significant momentum among corporate users.

A survey of 750 global IT administrators and C-level executives by the Yankee Group found that nearly four out of five businesses -- or approximately 80% --have at least a few Macs and the Mac OS X operating system installed in their networks.

"Although the Apple Mac hardware and OS X operating systems still represent a small niche, adoption and acceptance of Mac hardware and operating system software are growing at a steady and sustained pace not seen since the late 1980s," the firm said.

Of those who responded to the survey, nearly one-quarter said their firm had a "significant" number of Macs installed in their network, in excess of 30 or 50 units.

The Yankee Group cited a number of factors that it believes are fueling the adoption of Macs in the corporate world, such as Apple's sophisticated Safari web browser, iChat, an enhanced version of the FileVault security that provides disk encryption to protect data stored on Macs in the event a machine is stolen.

Also weighing in Apple's favor is the Time Machine embedded backup solution that ships as part of Mac OS X 10.5 Leopard, as well as its tool chest of Anywhere Applications features, such as embedded virtualization capabilities and the Back to My Mac feature that makes it easy for remote users to use the internet to remotely access files on their home computer using MobileMe.

Though not the focus of Yankee Group's study, Apple's encroachment on the enterprise market has been aided in large part by its entry into smartphone arena, as outlined by a Piper Jaffray report earlier this year.

With multifunction handsets a staple of most corporate ecosystems, the ability to market the iPhone to business users is changing, ever so slowly, the company's perspective on selling to the Enterprise, according to analyst Gene Munster.

"While Apple will let consumer demand drive the product decisions it makes, the company recognizes that every consumer is likely PC user at work, and we expect the company to focus on improving its outreach to Enterprise users," he said.

Following its recent iPhone Software 2.0 announcements with Exchange support and other enterprise solutions, Apple announced that over a third of Fortune 500 companies had sought access to the company's ongoing iPhone Enterprise Beta program.