A forthcoming makeover of the company's highly profitable AS/400 mid-range computers delayed potential buyers, and the company's troubled personal computer business continued to lose market share.

I.B.M. and Digital have dominated the market for mid-range computers.

"But let's face it: I.B.M. needs another mid-range computer like a hole in the head."

All three companies produce business software, primarily for mid-range and mainframe computers.

This week the company introduced a new line of mid-range computers that run the Unix operating system.

Demand also surged for mid-range computers and computer networks, all heavy users of memory-chip technology.

I.B.M. has relied on outside companies to supplement its own sales force since 1979 and it already has 360 value-added resellers selling mid-range computers.

The software will permit access to information stored on mainframe, mid-range and personal computers.

Revenues per employee increased 30 percent from 1986 to 1989, and the time to develop a new mid-range computer has been cut in half.

The Lowell, Mass., office-automation company said the weak earnings were caused by production delays and slow demand for a new mid-range computer.