STOCKHOLM (REUTERS) - Ikea, the world's biggest furniture retailer, is launching a new programme to top up the pensions of some of its staff, linking a bonus-style payment to long-term service and retirement income and offering the same to workers as managers.

The Swedish firm said on Thursday it would allot an initial 100 million euros (S$173 million) towards the scheme, called"Tack!", Swedish for "thank you", that would contribute to pension plans of employees with more than five years service.

Additional funding for the scheme would then be decided annually based on how the group fared against its targets. Ikea said it would only know at the end of next year how many of its about 135,000 employees would be eligible for the programme.

"The principles are fair and simple," the flat-pack furniture company said in a statement.

"Full-time co-workers in a country will receive the same amount regardless of unit, position or salary level. Part-time co-workers will receive a proportional amount in relation to hours worked."