But bond markets were mostly at an impasse, limiting moves, as they waited for a signal on when Spain may ask for financial aid, something necessary to enable the European Central Bank to buy its bonds.

Although Spanish bond yields have fallen in recent months and the country can currently finance itself, it is widely seen as having little choice but to ultimately seek help and markets are impatient for clarity.

The head of the Spanish Treasury said on Wednesday that Spain was ready to start funding itself for 2013, having nearly completed its targeted debt issuance for this year .

December Bund futures were 30 ticks lower at 140.17, having failed to hold above technical resistance levels in the 140.60 area the previous day but analysts did not see the sell-off running too far.

"The renewed concern over the trajectory of the euro zone economy coincides with more uncertainty as to when Spain has another political window to enter a bailout-lite," Credit Agricole rate strategist Peter Chatwell said in a note.

"We have to concede that Bund bulls may attempt to bring the 10-year yield down to the obviously strong resistance of 1.50 percent."

Gloomy economic data on Wednesday - including the euro zone's purchasing managers index falling to the lowest level since June 2009 in October - underscored the fragile situation in the region.