(Recasts with S&P comment, updates prices)
By Boris Groendahl
VIENNA, Feb 17 (Reuters) - Two leading ratings agencies said on Tuesday the ratings of emerging European banks and their west European bank owners could suffer as recession bites, and the warnings caused a sell-off in European stocks and currencies.
Moody's Investors Service released a report overnight saying banks in eastern Europe with large loan books faced downgrades and their parent banks' ratings could also weaken.
Standard & Poor's said in an interview with Reuters that the growing difficulties faced by Western banks in supplying funding to their subsidiaries in emerging Europe could prompt an overall ratings view for the region's banks.
The ratings agencies reminded investors of the crucial role a handful of Western banks has in keeping the former Communist bloc afloat after bankrolling its rampant growth in the boom years of 2005 to 2007.
The comments triggered sell-offs in financial stocks exposed to the region, drove the euro <EUR=> to two-month lows against the dollar and sent the currencies of Poland, the Czech Republic, Romania and Hungary to multi-year lows.
"There is no doubt that markets have decided that emerging Europe is the subprime of Europe and now everybody is running for the door," said Lars Christensen, head of emerging markets research at Danske Bank in Copenhagen.
Moody's said the recession in emerging Europe will be more severe than elsewhere due to large imbalances, and will put the financial strength ratings of local banks and their western parents under pressure.
Western banks led by UniCredit <CRDI.MI>, Erste Group Bank <ERST.VI>, Raiffeisen International <RIBH.VI> and Societe Generale <SOGN.PA> have bought most of emerging Europe's banking sector in past years to tap into rampant credit growth.
Banks' eastern franchises have in the past boosted parents' profits and helped them resist the temptation of structured debt products, but this boon has turned into risk now that economic crisis has the region firmly in its grasp.
"A widespread deterioration in the economic health of core markets in Eastern Europe is exerting negative rating pressure on subsidiaries and eventually may also lead to a weakening of the parent bank's ratings," Moody's said.
S&P analyst John Gibling said banks in eastern and central Europe were becoming more dependent on funding from their western European parents at a time when capital-raising was hampered by the financial crisis.
"We may have to review some of the bank ratings as the situation becomes bleaker," he said.
CURRENCIES, STOCKS FALL, SPREADS SOAR
The euro hit its lowest in more than two months against the dollar at $1.2565 as the report added to investors' worries over the region. The Polish zloty <EURPLN=> and Hungarian forint <EURHUF=> hit record lows against the euro and the Czech crown <EURCZK=> fell to its lowest since Oct 2005.
Shares in the western lenders that control emerging Europe's banking market also slumped. UniCredit hit a 12-year low of 1.111 euros, down 8 percent; Erste an all-time low of 7.00 euros, down 18 percent; KBC <KBC.BR> was down as much as 14 percent and Societe Generale <SOGN.PA> 10 percent.
Five-year credit defaults swaps on UniCredit also widened by 38.5 basis points to around 210 basis points.
"The market is increasingly pricing the bear case," said Francois Boissin, a bank analyst at Exane BNP Paribas. "The key risk for shareholders is to go through a heavy nationalisation process where you can lose everything."
With a relatively small number of banks concentrated in a handful of countries, some very exposed western European sovereigns have come under pressure for fears of a knock-on effect of potential emerging European bank failures.
Austria is by far the most exposed to the region, as its banks have lent the equivalent of 75 percent of Austria's GDP to clients in emerging Europe. [
]The Alpine country this month began to lobby for a stability package for emerging Europe due to be presented at the next meeting of European finance ministers, but is facing resistance from the European Commission and Germany. [
]The spread of Austrian and Greek 10-year bonds <AT10YT=RR> over German Bunds widened to a lifetime high of 124 basis points and 300.8 basis points, respectively, on Tuesday. (Additional reporting by Jane Baird and Carolyn Cohn in London, editing by Stephen Nisbet)