Burroughs Corp. and Sperry Corp., two mainframe computer companies that traditionally have lagged behind industry giant IBM, yesterday announced that they were discussing a merger that could create the world's second-largest computer company.

The announcement comes as computer manufacturers, including IBM, are experiencing an industrywide slump in projected revenue and profits that has forced thousands of layoffs and hammered down stock prices.

"The computer industry depression that's now occurring is part of a structural change in the industry," said Stephen McLellan, a Merrill Lynch vice president. "We now have a technological glut on our hands -- particularly in hardware."

With $5.2 billion in annual revenue, Sperry is the larger of the two companies, but a significant portion of its business is in such non-computer areas as farm equipment, aviation electronics and defense electronics.

Sperry's government business, which accounts for more than a third of its sales, is one reason why Burroughs, with $4.7 billion in annual sales, is reportedly interested in the merger. But neither Sperry nor Burroughs would go beyond a statement confirming they were exploring a common stock merger.

Burroughs and Sperry are, respectively, the third- and seventh-largest computer companies in the world. The bulk of their revenue comes from the sale of mainframe computers -- large corporate computers that traditionally have been the stronghold for IBM. With roughly $50 billion in annual revenue, IBM is the world's largest computer company.

The proposed merger could significantly improve the competitive position of both companies, but most analysts were skeptical that any real synergy could be wrung from the deal.

"This smacks of the troubled times of the late 1960s, when computer companies like Honeywell and General Electric were doing mergers and acquisitions," said Kidder, Peabody analyst William D. Easterbrook. "The problem then, as it would be here, is that it takes ages to put the different product lines together."

Because they are rival computer systems, Sperry's and Burroughs' computers are totally incompatible with one another. Consequently, a Sperry computer couldn't run software written for a Burroughs machine, and vice versa.

"It's not an easy merger," said Stephen P. Cohen, vice president with the Gartner Group, a Connecticut-based industry research firm. "You have radically disparate product lines" although there are distribution strengths, he added.

Analysts were also critical of the price for the transaction -- reportedly a one-for-one exchange of Burroughs shares for Sperry shares.

"It seems that Burroughs is paying a bit too much for Sperry," said Kidder, Peabody's Easterbrook. "Roughly 12 times earnings, which is rich, and a 20 percent premium to book value, which is also rich."

Easterbrook, who was referring to the fact that the price of a share of Burroughs is 12 times the per-share earnings of Sperry, said a lower multiple would be more reasonable.

"Wall Street sees more benefit for Sperry than for Burroughs," said Gartner Group's Cohen, pointing out that Burroughs shares were off 3 1/8 to close at 56 1/4 while Sperry declined 1/4 to close at 56 1/2.

Burroughs' 1984 profits totaled $244.9 million. Sperry's profits in its fiscal year ending March 31 totaled $286.7 million.

Both Sperry and Burroughs are longtime members of the second-tier computer manufacturers known as the BUNCH companies, for Burroughs, (Sperry) Univac, NCR Corp., Control Data Corp and Honeywell Inc. -- that have struggled to carve a niche in the mainframe computer market overwhelmingly dominated by IBM.

IBM captured roughly 60 percent of last year's $60 billion business in mainframes. Market share for the BUNCH companies has continued to erode over the last five years, analysts report, despite the introduction of new, more powerful machines.

"The BUNCH companies, in general, have not been able to get sufficient growth from their existing base or obtain new customers at a pace that matches overall computer industry growth," said Gartner's Cohen.

The BUNCH companies have tried to forge strategic alliances or mergers with other technology companies to diversify both their technologies and their customer base.

Sperry has been the most active of the BUNCH companies in that regard, publicly confirming that ITT Corp. was a potential buyer and hinting that it also had held discussions with Ford Motor Co.

The financial difficulties slicing across the entire breadth of the data processing industry may force a wave of mergers, acquisitions and joint ventures as companies scramble to survive.

"We're going to become more in the U.S. like the Japanese already are," said Kidder, Peabody's Easterbrook, pointing to the Japanese computer industry's web of joint-venture and vertically integrated companies.