The eurozone's government debt fell slightly to 87.4 percent of its gross domestic product (GDP) by the end of the third quarter last year from 87.7 percent at the end of the second quarter, the statistics office of the European Union (EU) said Monday.

On an annual basis, the debt-to-GDP ratio of the 17-nation euro area was higher than the 83.2 percent for the third quarter in 2010, Eurostat said in a statement on its website.

In the 27-nation EU, the ratio at the end of the third quarter increased from 81.7 percent to 82.2 percent on a quarterly basis, and rose from 78.5 percent to 82.2 percent year on year, according to Eurostat.

In terms of the forms of debt, securities other than shares accounted for 79.3 percent of the eurozone's and 79.7 percent of the EU's general government debt by the end of third quarter in 2011, while loans made up 18 percent and 15.8 percent, respectively, Eurostat said.

The highest debt-to-GDP ratio at the end of the third quarter of 2011 was recorded in Greece at 159.1 percent, followed by Italy at 119.6 percent, Portugal at 110.1 percent and Ireland at 104.9 percent, while Estonia, Bulgaria and Luxembourg saw the lowest at 6.1 percent, 15 percent and 18.5 percent, respectively.

This is the first time that Eurostat has published quarterly figures on government debt. Originally, only annual data was published.