Average weekly earnings fell by 1.5 per cent in the final quarter of 2011 to €698.54, according to new figures from the Central Statistics Office (CSO).
In the same quarter a year earlier, average weekly earnings were at €699.94.
Average weekly earnings are down by 4.3 per cent compared to the fourth quarter of 2008 when they stood at €720.57.
Pay per hour fell by 0.8 per cent to a average of €21.83 in the fourth quarter of 2011, the figures reveal.
The data show average weekly pay fell in eight of the 13 sectors covered by the CSO in the final quarter with the highest percentage decreases in construction and arts, entertainment, recreation and other services.
The largest sectoral increase was recorded in the professional, scientific and technical category.
In the three years to the end of the fourth quarter of 2011, public sector earnings fell by 5.3 per cent or €50.90 per week, compared to a 4.5 per cent or €29.21 decline in private sector earnings.
Employment in the public sector fell by 2.4 per cent in the 12 months to the end of last year to 392,300.
The CSO said public sector employment had fallen by 35,000 or 8.2 per cent since the final quarter of 2008.