* Belgian 2012 budget deficit set to rise above 3 pct/GDP
* Limited impact for larger French economy
* Belgium, France also guaranteeing Dexia borrowings (Adds Belgium's finance ministry comment, more on ruling, limited French impact)
BRUSSELS, March 19 (Reuters) - Belgium and France must include last year's 5.5 billion euro bailout of banking group Dexia in their budget deficit calculations, the European Union's statistics agency said on Tuesday.
Eurostat's decision will push Belgium's budget shortfall beyond a European Union ceiling of 3 percent of gross domestic product (GDP).
The country had reported a 2012 deficit that just squeezed under the 3 percent limit, but it did not include the 2.915 billion euros ($3.78 billion) it pumped into Dexia, which had to be rescued after the financial crisis.
With the near nationalisation of the Franco-Belgian lender factored in, the deficit would be at least 3.7 percent, its level in 2011. Belgium is seeking to bring its deficit back to 2.15 percent of GDP this year.
Belgium's finance ministry said it would revise its deficit figure for 2012, but said that it did not detract from its structural improvement of its budget. The revision would have no impact on its 2013 budget aims, it said.
Under EU rules, financial investments do not count towards deficits or surpluses, but capital transfers do.
State aid can count as a financial investment if a state receives a reasonable rate of return. In the case of Dexia, Eurostat said, no other shareholders were providing capital and it was incurring heavy losses.
"All of this confirms that this injection is not motivated by seeking market returns, as a private investor would do, but by the preservation of the stability of the banking system in Belgium and France," Eurostat said in a letter posted on its website.
The bailout was already included in the calculation of Belgium's debt, which rose to 99.6 percent of GDP.
For the much larger French economy, the impact is far slighter. France's contribution was also lower, at 2.585 billion euros, equivalent to little more than 0.1 percent of GDP.
France's deficit was 4.5 percent of GDP last year and is forecast to be about 3.7 percent of GDP in 2013.
Belgium, France and to a far lesser extent Luxembourg have also agreed to provide guarantees to cover up to 85 billion euros of borrowing for Dexia, which is essentially a holding of bonds and loans in run-off.
As of Monday, Dexia was using 56.4 billion euros of those guarantees, in addition to a further 11 billion euros of guarantees granted in 2008. ($1 = 0.7717 euros) (Reporting By Philip Blenkinsop. Editing by Jane Merriman)