The chief investigator into suspected fraud at Anglo Irish Bank announced his retirement Tuesday with months still to run in the probe, joining an exodus of public sector workers taking advantage of generous early exit pension terms.

With a hiring freeze in place since 2008 the government is set to make significant progress toward a target of cutting 37,500 staff by 2015, a reduction of almost 12 percent, through offering pensions based on pre-paycut salaries to those who leave by the end of February.

Ireland's Director of Corporate Enforcement Paul Appleby, who has led the probe into events leading up to the nationalisation of the scandal-hit Anglo for three years, will leave his post at the end of February.

Ireland has cut public sector wages by an average of 15 percent since 2008 but will only link pension schemes to reduced salaries from March, meaning retirees before then, such as Appleby, can enjoy packages based on pay levels enjoyed at the height of the country's Celtic Tiger economy.

The government has said it expects 9,000 workers to retire this year with many so-called frontline employees in the health service, education and police set to leave. A senior obstetrician warned this month that the flight of midwives could put the lives of expectant mothers and newborns at risk.

Appleby said his resignation would not impede the successful conclusion of the Anglo Irish probe and that he had advised the government of a number of colleagues capable of assuming his position pending a permanent appointment in a few months time.

He added that if his assistance was required after retirement he would make himself available.

A lawyer for the country's director of public prosecutions said last week that charges in the Anglo Irish case may be brought within two months. However, Appleby's team was also granted a further six-month extension to continue its investigation.

Ireland's jobs minister, under whose aegis Appleby's office operates, said he would work with the department of public expenditure to fill the post.

Minister for Public Expenditure Brendan Howlin has said 3,000 people could be taken on this year to fill any gaping holes in public services.

(Reporting by Padraic Halpin; Editing by Greg Mahlich)