If Apple ever decides to let its Mac OS X operating system outside of its confines, the company can count Dell founder and chairman Michael Dell as a possible customer.

With the recent news that Apple plans to become a fellow customer of Intel for x86 processors, Dell has expressed interest in selling Mac OS X-based PCs, he said in an email to Fortune published on the magazine's Web site Thursday.

"If Apple decides to open the Mac OS to others, we would be happy to offer it to our customers," Dell wrote in the email. A Dell spokesman confirmed Thursday that the email exchange took place.

Apple, however, is not keen on striking a deal with the world's largest PC vendor.

"Mac OS X will only run on Macs. Apple has no plans to sell Mac OS X software to run on PCs," an Apple spokesperson said in an email response to questions about Dell.

Dell's interest in Mac OS X raises numerous questions about how such a partnership would work. Dell's current PC product strategy is famously one-sided: Microsoft's Windows operating system and Intel's processors for all. Dell executives believe this arrangement allows them to keep their operating costs as low as possible.

However, Mac OS X, with its Unix underpinnings and secure reputation, might pique the interests of many IT managers looking for a low-cost PC that is easy to maintain. And Dell's position as the industry market share leader could expose Mac OS to a much wider range of users.

But Apple can't afford to let Mac OS X loose right now, said Roger Kay, vice president of client computing with IDC, Digit's sister company. If Mac OS X could be separated from Apple's hardware, hackers would have pirated copies of the operating system out on the streets with little delay, he said. This would cause great harm to Apple's business model, which emphasizes its tight control over the entire combination of hardware and software as a premium product, he said.

At least one analyst believes that Apple is due for a day of reckoning with this strategy, especially now that it plans to move to x86 chips. Nathan Brookwood, principal analyst with Insight 64, thinks it is only a matter of time before someone in the PC industry sues Apple for "tying" its operating system to a specific type of hardware available only from Apple.

Digidyne, then a division of Fairchild Camera and Instrument, successfully pursued a tying case against Data General in the 1980s in which Data General was rapped for licensing its Nova operating system only to purchasers of its hardware.

"If you sell software that can run on hardware that you do make and hardware that you don't make, you can not require people to buy your hardware to run your software," Brookwood said. If Dell really wanted to sell Mac OS X hardware, it could force the issue through the legal system, he said.

Dell's interest in Mac OS X also appears to run counter to its processor strategy. The company's reluctance to use Advanced Micro Devices' chips is based partly on the additional costs Dell would incur setting up a product development and testing team for AMD's products, Dell CEO Kevin Rollins said at the company's analyst meeting in April.

However, supporting a second operating system would involve training thousands of Dell employees on the ins and outs of Mac OS X and setting up separate product development teams. Dell is willing to do this for its server customers interested in the Linux operating system, but the company ended Linux support for consumer PCs several years ago. Large business customers can still get Linux PCs or workstations through Dell by special arrangement.

In the end, it's hard to really get a sense of Dell's true interest in Apple, Kay said.

"It's very much Michael Dell. It's cryptic, you can interpret in a number of different ways," he said.