The Commission would therefore launch an in-depth investigation in the coming days for the two sides to possibly reach an agreement.

Once the in-depth investigation has been launched, the sides have a month to provide their comments.

Should the two sides fail to find common ground on the privatisation, the Commission could demand recovering the unlawful state aid NLB had received.

However, the unofficial sources also said that the Commission hopes for the investigation to yield results.

In December, the Slovenian government decided to propose to the EU for the start of the NLB privatisation to be postponed until late 2018 and for a blind trustee to be appointed for the bank for the meantime.

This was the country's latest proposal in efforts to defer the sale of the bank, which had been promised in exchange for state aid in 2013. It entails the start of privatisation after the 2018 general election and its completion in 2019.

To bail out NLB four years ago, Slovenia had committed to selling 75% minus a share. Under the initial timeline, at least 50% of the bank would have to be privatised by the end of 2017 and the rest by the end of 2019.

Last year, an attempt to sell the bank fell through after tentative pricing failed to meet government expectations.