IBM Cutbacks to Hit Profit by $5.4 Billion : Consolidation: The number of workers accepting job buyouts is double the original estimate of 20,000.

IBM said Tuesday that it will consolidate manufacturing to cut costs and expects about 40,000 employees to accept voluntary job buyouts or early retirement this year, double the original forecast.

The leading computer maker said it would reduce earnings by about $5.4 billion before taxes to pay for the actions, resulting in a loss in the current quarter.

IBM said this accounting charge against earnings would be partially offset by a $1.9-billion tax benefit, but it would not predict what the impact would be on overall 1992 profit.

The company said it did not expect to close any plants outright, but that manufacturing would be reduced at some sites.

Some employees will be required to move or to learn new skills to keep their jobs. No layoffs are planned, keeping with IBM’s longstanding tradition.

The company said it had not yet determined which plants would be affected, but that it primarily would involve those that make computer chips and, secondarily, mainframe computers.

IBM’s principal domestic chip plants are in East Fishkill, N.Y., and Burlington, Vt., though one industry source said the Burlington plant would be largely unaffected. Mainframe plants are in Kingston and Poughkeepsie, N.Y.

The company said the action was worldwide, and that many of its 30 plants around the globe would be affected.

IBM has been attempting to cut costs for several years as it contends with a slowdown in the computer industry and increased competition from smaller, lower-cost competitors.

By year-end, IBM said it will have reduced its payroll by about 25% since the peak of 406,000 employees in 1985. About 28,000 of those workers left under a job buyout program that expired July 31.

IBM made the announcement after the 4 p.m. close of trading on the New York Stock Exchange. IBM shares had fallen $1.75 to close at $81.