The press release from the Commission says that there is doubt that these injections had been granted on market terms.

The Commission noted that the flag carrier had been facing financial difficulties for years and had had a negative net result since at least 2008.

The four capital injections were carried out in 2007, 2009, 2010 and 2011 either directly by the state or through state-owned PDP holding or its predecessor KAD fund, according to the Commission.

The 2007 and 2009 capital injections were subscribed almost entirely by KAD, while the 2010 capital increase was funded by PDP (80%) and two travel agencies (20%), the Commission notes.

In 2011, Slovenia and PDP injected EUR 50m in cash into Adria Airways, while a number of banks - including state-owned NLB - converted EUR 19.7m of debt into equity.

In addition, the Commission found that PDP and Aerodrom Ljubljana, state-owned airport operator, acquired 52.3% and 47.7%, respectively, in the flag carrier's subsidiary Adria Airways Tehnika between October 2010 and March 2011.

The flag carrier believes that none of the injections or the sale of Adria Airways Tehnika were a form of state aid and they were all carried out on market terms.

Adria Airways said in a press release it was not surprised over the Commission's decision, as it had been in contact with representatives of the Commission and the state regarding this issue.

Finance Minister Janez Šušteršič said he expected EU Commission's findings in this case to resemble that in the case of sports equipment maker Elan, which was ordered by Brussels to return EUR 10m in state aid.

Also similar to that case, he says Slovenia would dispute such a decision and try to reduce the sum that would have to be repaid.

He believes that the investigations are the consequence of Slovenia's way of managing state assets, as there are a number of para-state funds, which may be persuaded into helping companies but fail to respect all the rules.

"These reproaches, decisions do have a basis, but it is in Slovenia's interest to dispute them and try to get measures that are as mild as possible," said the minister.

The investigation also provides an opportunity for any interested third parties to submit comments on the measures investigated, the Commission's press release noted.