Many are retiring to avoid being switched back to beat duties, escape discipline charges or because of low morale, bring the likely number of retirements to 240 in the year to April with only 200 expected.
Paying the pensions of the extra officers will cost £1 million which will have to be taken from the force's operational budget. This year more than £23m of the force's money will be paid to 2,700 retired officers because their pension scheme is insufficient.
Police Authority acting treasurer Derek Smith said: 'The number of officers retiring early poses a potential threat to the finances of the authority'.
The police authority yesterday approved a plan to shave more than £5m off spending plans to April 1994.