About 3,500 civil servants are expected to join the voluntary retirement scheme, costing taxpayers $1.1 billion. But officials believe savings in salaries will cover the compensation in two to six years. The Civil Service Bureau has picked 70,000 staff in 59 grades whose jobs are obsolete. These include lift operators, clerical staff and general workmen. The Finance Bureau said staff with 25 years' service would find the scheme most attractive. Those affected are already entitled to normal pension payments worth up to $2.2 billion a year. Each will be given six to 20 months' salary as compensation for early retirement. Officials stressed the scheme had no quota but initially planned to seek lawmakers' approval for compensation worth up to $1.1 billion in light of an estimate that five per cent of staff would be affected. A government spokesman said services could be contracted out after the officers left. Staff costs could be cut by 30 per cent, which would cover the compensation in two to six years. 'Compared to the total pension we pay each year, I think we can afford the additional cost,' the spokesman said. The scheme is part of a drive to trim bureaucracy by 10,000 posts in three years. The Executive Council approved the compensation package on Tuesday after consulting staff. Chairman of the Federation of Civil Service Unions, Leung Chau-ting, who belongs to the clerical grade, said the scheme was not attractive enough. With $20,010 pay a month and 30 years' service, Mr Leung, 50, could pocket a monthly payment of $5,335 until death and a one-off $1.24 million if he retired voluntarily. But he decided not to join the scheme because 'I won't be able to find a job with pay as good as what I have now'. Officials would try to approve all applications as long as public service is not compromised. Seniority may be considered if too many opt for the scheme. 'There will be no compulsory element in the scheme. Applications will be entirely voluntary,' a government spokesman said. Applications will open in September or October subject to approval by the Legco Finance Committee.