New figures from the Central Statistics Office show that average weekly earnings fell by 0.3% in the fourth quarter of 2012 compared the same time the previous year.
The preliminary figures show that average weekly wages eased to €695.80 in the last three months of 2012 from €697.65 in the last three months of 2011.
The CSO figures also reveal that average hourly earnings dipped to €21.96 in the fourth quarter of 2012 compared with €22.03 the same time the previous year, down 0.3%.
Average weekly paid hours were 31.7 in the three month period, unchanged from the same time in 2011.
In the four years to the end of 2012, average weekly earnings across individual sectors of the economy showed changes ranging from a drop of over 11% for the construction sector and gains of 4.3% for the information and communication sector.
Today's figures show that weekly earnings in both the private and public sector rose by 0.3%, bringing average weekly earnings to €623.43 and €921.99 respectively in the fourth quarter.
The CSO said that the estimated number of people working in the public sector - including the semi-state bodies - declined by 2.3% over the year to total 381,800.
It added that the reduction in numbers in the public sector over the four years from 2008 to 2012 now stands at 45,500, or 10.6%.