IBM to Unveil New Versions of Mainframes : Computers: The company hopes that the additions will end a long sales slump.

Hoping to end a long sales slump, IBM this week will unveil a slew of new mainframe computers.

IBM on Wednesday will show off half a dozen new versions of the powerful, multimillion-dollar machines, favored by airlines, insurance companies and banks that keep track of millions of customer records or other data.

Slightly more than half of IBM’s profits come from mainframes and associated equipment and services, making the success of the new products crucial, analysts say.

The models will round out IBM’s first new mainframe line in a generation, which the world’s largest computer maker announced with much fanfare in September, 1990.

Besides the mainframes, IBM will unveil new software and other products.

International Business Machines Corp. told reporters in July that demand for those computers, called the Enterprise System-9000, is strong despite a computer industry slowdown and the recession. IBM just started shipping the machines in volume to customers this month.

That should bring a needed boost to IBM’s finances. Operating profit plunged 74% in the first half of the year as revenue fell 8%.

IBM, based in Armonk, N.Y., is in danger of reporting its first decline in annual revenue since 1946 unless sales pick up this fall, analysts say.

IBM’s stock rose $1.625 to $101 in New York Stock Exchange trading.

Rick Martin of Prudential Securities Inc. estimates that IBM revenue will fall about 5% from last year’s $69 billion. Martin and other analysts predict IBM’s profit will plummet by more than half, to about $2.6 billion from last year’s $6 billion.

IBM also faces strong competition from two companies that make mainframes that run IBM software. Customers can buy machines from Hitachi Data Systems Corp. and Amdahl Corp. and integrate them easily with their IBM mainframes--for about 20% less money, Martin said.

A key to restoring IBM’s financial health is the mainframe line.