Fitch decided to scrutinise NLB's rating at the end of April. The bank's credit profile had since been "stable" and continues to be commensurate with a one-notch higher rating, the agency said.

This means that if NLB is not affected by a potential delay in privatisation, Fitch could improve its rating by one notch.

In this case, the agency expects NLB's financial profile to improve, as reflected in the significant moderation of asset quality risks, stronger earnings, and solid capital and liquidity buffers.

If the bank is not privatised as planed and if the delay affects its standing, profitability and capital, the rating could also worsen.

In line with a decision on changed commitments taken by the European Commission last August, Slovenia must sell at least 50% plus one share of the fully state-owned bank by the end of 2019.

The remaining 25% plus one share should be sold by the end of 2019. The decision also contains compensation measures the bank needs to carry out until sold.

In Fitch's view, the agreement to extend the privatisation deadlines is "credit positive".

Privatisation procedures have already been launched. On Monday, NLB and Slovenian Sovereign Holding published an intention to float on the Ljubljana and London stock exchanges, which refers to at least 50% plus one share and 75% minus one share at the most.

A prospectus for the initial public offering is expected to be released on 26 October.