Almost €4 billion from the National Pension Reserve Fund which was invested in Bank of Ireland and Allied Irish Bank last year has been written off, according to the annual report of the Comptroller and Auditor General.

The report shows that up to the end of 2010, the NPRF invested €11.35 billion in Ireland's two biggest banks. However, as a result of an impairment loss of €3.7 billion, the value of this investment fell to €7.6 billion.

State expenditure fell by 9.5 per cent to €53.8 billion in 2010, compared to €59.5 billion a year earlier, according to the Comptroller's report. Public borrowing increased to €148 billion.

The report highlights a high level of wastage of funds by State agencies relating to Public-Private Partnerships.

It shows the National Roads Authority is obliged to make payments totalling between €5 million and €5.5 million this year to the private operators of the M3 motorway and the N18 Limerick Tunnel because of declining road traffic.

The payments are due because traffic volumes on the routes have fallen below agreed thresholds.

Elsewhere, the report indicates that almost €1.5 million has been paid out in costs associated with developments of private hospital facilities on public hospital sites, even though talks with possible bidders have now ceased.

The report also notes that the Department of Social Protection recorded welfare overpayments of over €83 million last year, with as much as €26 millionof this related to fraud.

The total outstanding commitments of central government departments and agencies in respect of contracted PPP projects at the end of last year is estimated at €4.3 billion.

The Comptroller's study shows that net receipts of €3.94 billion were received last year from Corporation Tax. This is €2.5 billion lower than in 2009.

Receipts into the Central Fund in 2010 totalled €35.6 billion. This represented an increase of €851 million relative to the 2009 receipts of €34.8 billion.

The report also shows that €725 million was issued in 2010 to acquire shares in banks bringing the cumulative cash investment through the Exchequer to €4.73 billion.

The State paid €979 million on servicing the national debt last year, an increase of 37 per cent on 2009.

Some €73.4 million has been paid out on consultancy costs linked to the banking crisis. This includes €35.1 million for financial advice, €22.5 million for legal services and a further €15.6 million for accounting-related services.

The value of bank liabilities guaranteed by the State at the end of June this year was about €123 billion, according to the report. A further €74 billion is covered by the guarantee on deposits held in the six banks provided in September 2008.

The reports shows the Central Bank had provided €56 billion of emergency funding to the banks at the end of June.

The State contributed €1.35 billion to the European Union budget and benefited from EU budget expenditure of €1.88 billion.

Capital expenditure costs were estimated at €6.3 billion in 2010. Of this, approximately €2 billion was spent on roads and public transport. Some €495 million was invested in water services while €746 million was invested in social housing and estate regeneration.

A further €589 million was spend on grants or assistance to private enterprise in agriculture and industry while €616 million was invested in building and equipping of education facilities.

The cost of administering central government services was estimated at €2.6 billion in 2010.

A total of €4.8 million was paid to political parties under the Electoral Act last year, according to the report.