Erste Group Bank AG, one of the four biggest lenders in the former communist part of Europe, keeps Bulgaria in its plans, but in the longer term, its chief executive has said.

"If we look into the long term, the market we have to move into urgently - and urgently means for me sometime in the next 25 years - is Poland," Chief Executive Andreas Treichl said in response to a question after a meeting of the shareholders on Tuesday.

"Afterwards we will probably relatively soon get into Bulgaria. At the moment we have no expansion plans in this direction."

In his words Ukraine remains a "very interesting market" for the long term.

Andreas Treichl praised Ukraine's commodity wealth and geography, but voiced concerns over the lack of political stability in the country.

UniCredit SpA, Erste Group Bank AG, Raiffeisen Bank International AG and Societe Generale SA are the four biggest lenders in the former communist part of Europe.

The Bulgarian banking system is concentrated, with most of the assets owned by large financial institutions from the eurozone.

The five biggest banks in Bulgaria are UniCredit Bulbank; DSK Bank, a unit of OTP Bank Nyrt., Hungary's largest bank; United Bulgarian Bank, owned by the National Bank of Greece SA; Raiffeisenbank Bulgaria and Eurobank EFG Bulgaria.

Greek banks control about 28% of banks' total assets in Bulgaria.