The long-term Issuer Default Ratings (IDRs) outlook of Bulgaria's Societe Generale Expressbank, Allianz Bank Bulgaria and Bulgarian Development Bank have been upgraded to positive by Fitch Ratings.

The outlook on Bulgaria's largest domestic-owned bank, First Investment Bank has been also upgraded to stable from negative, Fitch said in a statement late on Tuesday.

The upgrade followed Tuesday's news that Fitch Ratings has also upgraded ITS outlook on Bulgaria's currency ratings to positive from negative, reflecting the country's declining debt levels and recovering economy.

Fitch now has Bulgaria's foreign and local currency ratings at BBB- and BBB, or one notch and two notches above junk grade, respectively.

The credit ratings company said an upgrade is possible if Bulgaria's banking sector shows clearer evidence of stabilization, and the budget deficit and external debt are reduced further.