Brian Lenihan has signed a ministerial order designating the first group of banks and building societies to participate in the state guarantee scheme.
Institutions now covered include AIB, Bank of Ireland, Anglo Irish Bank, Irish Life & Permanent and the Irish Nationwide and EBS building societies.
The liabilities of the six Irish-owned financial institutions are now guaranteed by the State under the laws of Ireland for a two-year period to September of 2010.
The central objective of the scheme is to provide security to depositors and investors with the full protection of the State.
The Finance Minister has indicated that he expects to make further orders shortly for Irish-based, foreign-owned banks who have been invited to participate.
Those eligible are Ulster Bank, First Active, Halifax Bank of Scotland, IIB Bank and Postbank.