The trade union Unite has criticised the latest proposals from IBM in a dispute over the company's pension scheme.
IBM announced to employees on Friday that it would close its final salary pension scheme in April 2011, a year later than originally proposed.
It also announced enhanced company contributions for the first two years to a replacement money purchase scheme, and the retention of current death and ill health benefits.
But Unite said the changes lacked substance and represented "pain for employees and gain for executives." The union says the proposals have caused a backlash from thousands of staff.
Peter Skyte, Unite national officer for IT and communications, said: "The latest IBM proposals, whilst modifying some of the detail and mitigating some of the impact in the short term, do little to alter the substance of the company's original proposal and still propose the closure of the defined benefit pension scheme and replacement with a vastly inferior money purchase scheme."
Unite predicts that between 700 and 1000 IBM staff will apply for early retirement before April 2010 to avoid retiring under the less generous provisions in the new scheme.
IBM staff in their mid 50's could lose up to £200,000 as a result of the changes, said Unite.
IBM staff planning to retire early under the new pension arrangements will pay a penalty of 7% of their pension fund for each year before the standard retirement age, compared to 3% at present, it said.
In a separate move, Unite plans to organise a ballot for industrial action over plans by Fujtisu to close its final salary scheme.