Unisys Corp. on Monday unveiled its strategy to link its computers with those of competitors, saying it would provide a method unmatched by IBM, Digital Equipment Corp. and other computer makers.

Unisys, the nation's third-largest computer company, said its Integrated Information Environment would provide software that would mask the differences between Unisys machines and those of other companies so they can be joined in a network.Unisys said it would do this by adhering to the increasingly popular "open systems" strategy, in which computers and software follow sets of industry standards so they can be used interchangably.

"It's a milestone in the strategy we've been pursuing since Burroughs and Sperry became one," said James Unruh, Unisys' president and chief executive, referring to the 1986 merger that formed the company.

However, Unisys' plan is similar in many aspects to the strategies of other computer companies as they contend with computer users who want their machines to operate together no matter which brand. That means Unisys will face tough competition.

"They have no choice - it's a standards world," said Daniel Mandresh, a computer analyst at Merrill Lynch & Co. But, he said, "You've got to capture the customer before the other guy."

As part of its plan announced at a news conference here, Unisys said it would provide a new version of the operating system for its mainframe computers. Operating systems control a computer's internal functions.

The new mainframe operating system will allow the machines to serve as "information hubs" in networks with other types of computers, Unisys said.

That strategy is similar to a plan announced last month by International Business Machines Corp., which also said it wants to position the mainframe at the center of computer networks that link personal computers and midsize machines.

But Unisys claims its strategy for linking computers of different makes differs from that of IBM and other companies because it is not based on the computers themselves but on an overlay of software based on industry standards.

The strategy also differs from that of NCR Corp., which announced last month that it would replace its entire computer line with models based on industry standards.

In contrast, Unisys has said it will continue to make its two older mainframe lines, based on proprietary standards, but will mesh them with other machines with the new software.

On another matter, Unruh said the company's directors put great thought into their decision last week to eliminate Unisys' quarterly dividend of 25 cents a share. The move is designed to save cash and help reduce Unisys' debt. He said that "philosphically" Unisys wanted to pay stockholders a dividend, but that it would not resume doing so until "the company's profitability and capital structure warrant it."

Unisys, based in Blue Bell, Pa., has been struggling to return to profitability since reporting a $639 million loss last year. Last October, it announced it would eliminate more than 8,000 jobs, close plants and refocus its mishmash of product lines inhereted from its predecessor companies.

Unruh said the company expected to report a loss for the third quarter but that it expected a profit in the fourth quarter.