LONDON, Nov 20 (Reuters) - European stocks and currencies were hit on Friday by a wave of speculation about the risk of default on Ukraine’s sovereign and sovereign-guaranteed debts, even though analysts said there was no fresh development to trigger the sudden fright.

Ukraine's state railway last week said it was seeking to restructure a $550 million syndicated loan organised by Barclays BARC.L after failing to repay a portion of it.

Since then, investors and analysts have been examining the implications of the rail debt restructuring on Ukrainian sovereign debt and other quasi-state obligations.

“The company has other external liabilities which have a sovereign guarantee. So the question then, are there cross default clauses back between these two separate liabilities and then back to the sovereign?” said Tim Ash, head of CEEMEA research at RBS, in a client note released late on Thursday.

“Will Ukraine default on its sovereign liabilities? Never say never.”

Ukraine’s state railway was unavailable for comment.

The euro hit a two-week low against the dollar EUR=, with the latest Ukraine worries being cited against a background of growing yearend risk aversion ahead of next week's Thanksgiving holiday in the United States. Central European currencies in Hungary EURHUF=, the Czech Republic EURCZK= and Poland EURPLN= also fell, along with European banking stocks, including Commerzbank CBKG.DE, Swedbank SWEDa.ST and Societe Generale SOGN.PA.

Western banks’ exposure to fragile eastern European economies has been a concern throughout the global economic crisis.

The cost of insuring Ukrainian debt has been rising in recent weeks, after Fitch downgraded the country’s sovereign debt rating and the IMF suspended its $16.4 billion standby programme to Ukraine after parliament passed a bill to raise the minimum wage by over 20 percent in defiance of the Fund’s recommendations [IDnLB138580].

Prime Minister Yulia Tymoshenko has warned that the economy will face extreme difficulties without the release of a $3.8 billion IMF loan tranche this month.

Ukraine’s five-year credit default swaps showed little change on Friday, traders said, but are already trading at elevated levels above 30 percent upfront.

This means it costs over $3 million upfront to insure $10 million of Ukrainian debt, in addition to annual costs of $500,000 a year.

Ukraine's hyrvnia UAH=, which is closely managed by the central bank, fell slightly.