(FORTUNE Magazine) – ITT is reportedly planning to cut as many as 630 of the 900 employees at its Manhattan headquarters through early retirement and layoffs. Honeywell announced it would eliminate 4,000 jobs, or 4.3% of its worldwide work force, by year-end. Northwest Airlines, which is merging with its Minneapolis rival, Republic Airways, will lay off nearly 800 employees, including managers and baggage handlers; a spokesman said the move is ''part of the orderly realignment of the work force'' leading to the merger, effective October 1. IBM, announcing it would stick with its no-layoff policy, said it would ease the rules for early retirement as part of an effort to reduce its work force by at least 8,000 next year. Union Pacific Corp., the nation's third-largest railroad, agreed to buy Overnite Trans-portation Co. for $1.2 billion to create a transcontinental shipping system. The deal, which must be approved by the Interstate Commerce Commission, comes as other railroads are also diversifying to offer one-stop shopping to shippers. Newstrends -- captions