Poland's banking system outlook was kept negative by rating agency Moody's, Moody's said in a statement on Tuesday.

The main drivers of the outlook are the slowdown in economic growth in Poland, the consequent asset-quality deterioration and constrained ability to grow and diversify revenues as well as banks' potential exposure to a significant asset-liability mismatch risk, particularly in foreign currency, Moody’s said.

In addition, Moody's expects that the increasingly volatile and uncertain external environment and encouragement from West European parents will push Polish banks to accumulate liquidity and intensify competition for customer deposits, thus diminishing their interest margins.