Italy's public deficit climbed to 3.2 percent of the gross domestic product in the second quarter, compared to 2.5 percent a year earlier, according to official figures released on Thursday.
This brings it slightly over the European Union ceiling of 3.0 percent of GDP for public deficits on budgets by the central state, welfare systems and local authorities.
In the first six months of the year, the public deficit had dropped by 0.1 percent to 5.3 percent, the National Institute of Statistics ISTAT said.
The figures are preliminary and vary strongly from quarter to quarter, ISTAT said, adding that the calculations do not exactly match the European Commission's annual figures because certain operations are not included.
Italy's public deficit for the year is forecast at 3.9 percent, but according to Fabio Fois from Barclays Capital, in light of the half-year primary deficit, the government may miss its target by 0.2 or 0.3 percent.
The rise in deficit in the second quarter was due to a 1.6 percent increase in public spending over a year, while government revenue rose 0.1 percent.
The primary deficit, excluding interest payments on debt, dropped to 2.1 percent of GDP in the second quarter, ISTAT said.
The primary deficit, excluding interests on debt, went up to 2.1 percent of GDP.
Italy's enormous debt of over 1,900 billion euros, which comes to around 120 percent of the Gross Domestic Product, spooked markets over the summer, as investors feared the country may succumb to the eurozone debt crisis.
On Thursday morning, the Italian Treasury placed 7.85 billion euros (10.7 billion dollars) in bonds with sharply higher interest rates, signalling renewed discontent on the markets.
The Italian treasury had hoped to issue between 5.5 and 9.0 billion euros. Demand was 11.5 billion euros, according to the Bank of Italy -- a disappointing result according to some analysts.
"All in all, today's issue was not at all satisfying," Annalisa Piazza from Newedge told AFP.
Interest rates rose most notably on bonds expiring in 2014 to 4.68 percent compared to 3.87 percent at the last similar operation.
They also rose to 5.86 percent compared to 5.22 percent for bonds expiring in 2022 and to 5.63 percent compared to 4.58 percent for those expiring in 2015.
The interest rates would cost Italy dearly but were still "maintainable" for the Treasury, according to a Milan analyst.
The rise in borrowing prices comes after efforts by Rome to reassure investors by adopting an austerity package in mid-September which aims to reduce the country's mountainous debt by 2013.