The zloty shed 0.2 percent to trade at 4.2855 against the euro at 0931 GMT, still near 2-month highs.

Warsaw's blue chip equities index fell 1.2 percent, retreating from a 3-month high set in the previous session.

The NBP is expected to keep its benchmark rate on hold at 1.5 percent, and repeat its projection at a news conference that rates could stay at record lows at least until the end of 2019.

While global markets are gripped by fears of a global economic slowdown this year, third-quarter output data released in the past weeks in Central Europe continue to indicate robust growth, around 5 percent in annual terms in the case of Poland and Hungary.

With crude prices retreating in the past two months, earlier worries over inflation dissipated in the region. As a result, government bond yields fell sharply, without hurting currencies.

Poland's November data released last week showed a slump in annual headline inflation to 1.2 percent, below the NBP's target range between 1.5 and 3.5 percent.

Inflation is expected to rise again next year, even though the region's economies are seen joining a trend of economic slowdown in their main export markets.

"Supporters of loose monetary policy who would want the MPC (Monetary Policy Council) to stay idle at least until the end of 2019 outnumber these central bankers, who are frustrated with no response to uncomfortably high projected CPI path," Santander Bank analysts said in a note.

Polish bond yields were mixed, with the 10-year yield ticking up 1 basis point to 3.05 percent.

Hungary's corresponding yield, at 3.09 percent, almost closed a gap with the better-rated Polish paper, for the first time since June, as yields dropped ahead of a rare buyback auction by the Hungarian debt agency AKK.

The breakdown of Hungary's third-quarter economic output growth continued to show a strong rise in household consumption, but some slowdown next year remains inevitable, analysts said.

"With news that EU fund inflows have picked up, and after a Eurobond issue in September, AKK is in a very good position," one Budapest-based fixed income trader said.

"It is cheap to finance forint positions... and sentiment remains positive despite the past decline in yields. We will have the year's last primary bond auction tomorrow, so there is support from the supply side as well," the trader added.