Expectations that the U.S. Federal Reserve would begin to scale back — or "taper" — extraordinary economic stimulus first hit markets in May, prompting many investors to pull funds out of emerging markets seen as risky.

Financial markets have since calmed somewhat even as the Fed decided to trim $10 billion from its monthly $85 billion bond buying, but that may prove just a temporary lull for countries with large current-account or budget deficits.

"Fed tapering is a story which we analyzed I think every week in the last year. It's still an open issue," Adam Balog, deputy governor of Hungary's central bank, told a Euromoney conference on central and eastern Europe.

"One thing I would emphasize is it doesn't mean tightening monetary policy, it means less loosening (of) monetary policy. And it does not mean a higher interest rate arena for us."

The National Bank of Hungary has cut its base rate to 3 percent from 7 percent since August 2012 to boost growth. The country's large debt leaves it exposed to potential turmoil, Balog acknowledged, but he also cited its stable economic indicators and currency.

Christian Popa, Romania's deputy central bank governor, said the initial panic-like exodus of funds from many emerging markets last year had now given way to something healthier.

"(Investors) are now discriminating between (these countries) on the basis of fundamentals," he told the conference, noting those with large external or fiscal deficits or with no track record of delivering structural reforms were vulnerable.

Romania's financial backstop with the International Monetary Fund (IMF) and European Union provided some shelter, as did its ability to chop current-account and budget deficits, he said.

But still, he added: "Any kind of tapering or tightening ... will have an impact on Romania. It is very difficult to predict what that impact will be because it will have an impact on everybody."

Croatian central bank Governor Boris Vujcic agreed that the jury was still out on tapering's impact. "We can only say at the moment there are no significant effects that ... influence our policy or our situation."

CZECHS SANGUINE

Aasim Husain, deputy head of the IMF's European department, told Reuters this week that countries like Turkey, Ukraine and Serbia with big external deficits were at risk, as were those with large financing needs including Hungary and Croatia.

Apart from Turkey, economies in the region have so far weathered concerns about reduced U.S. stimulus much better than emerging Asia.

Turkey, like India and Indonesia, has been a target because of its high current account deficit, but its central bank deputy governor on Tuesday played down the potential impact, saying most of the damage was done back in May.

But the Turkish lira weakened again on Wednesday as investors continued to worry about tapering effects as well as a government corruption scandal, putting further pressure on the central bank to hike interest rates.

Bank of Lithuania Governor Vitas Vasiliauskas said tapering could have an indirect impact by pushing up the dollar against the euro, making global energy prices, which are dollar-denominated, more expensive.

"But if we compare international prices for oil, for gas, and even if we (keep) in mind possible changes of the prices in the future, I don't see any big influence," even for several years into the future.

Czech National Bank board member Lubomir Lizal was the most sanguine of the central bankers at a panel discussion, thanks to a banking system awash with excess liquidity thanks to its tradition of having relatively high levels of deposits.

"For us it's almost a non-issue in terms of the direct effect," he said.