The Greek economy shrunk by 6.9% on an annual basis in the third quarter of 2012.
The state statistics agency has revised a previous estimate of 7.2% issued last month. This followed a contraction of 6.3% in the second quarter of 2012.
AFP reports the economy has contracted by 22% since 2008. In 2011, the economy shrank by 7.1%.
The government and the European Commission are forecasting a return to growth in 2014, when the economy should grow by 0.2%.
Prime Minister Antonis Samaras has made achieving growth the top priority for the government so Greece can meet its commitments to international creditors.