Unite is balloting staff at Fujitsu on jobs, pay and pensions with a view to taking industrial action over planned cuts to some 1,500 employees pension funds.
Staff at the firm, which includes Fujitsu Services and Fujitsu Technology Solutions last month voted in favour of striking against proposals to overhaul the final salary pension scheme which would slash the total package by 20%.
The largest union in the UK, Unite has served Fujitsu with seven days notice of the ballot, due to start on 12 October, and the result will be available by 30 October.
"Unite members are asking why they should lose their jobs and tighten their belts when last year the company paid out £150m to shareholders and around £1.6m to two directors as compensation for loss of office," said Unite National Office Peter Skyte.
He said Fujitsu Services made £200m profit before taxation this year, the parent had raised £500m from a share sale and senior management had forecast record profits for the current fiscal year.
"Fujitsu remains a highly profitable company and our members are insisting that the company must treat them fairly and increase pay, provide decent pensions and consult meaningfully to minimise jobs losses," said Skyte.
The firm also plans to cut up to 1,200 jobs in the UK, around 10% of the workforce to counter an anticipated shortfall in revenues.