The European Central Bank held its main refinancing rate at a historic low of 0.75 percent on Thursday, as it continues to assess the impact of its latest anti-crisis measures.
ECB watchers had not been expecting the central bank to ease borrowing costs in the euro area this month as such a move would likely have little effect on the region's sputtering economy at the current juncture, they argue.
ECB chief Mario Draghi was scheduled to explain the reasoning behind the move at his regular news briefing afterwards.
Two months ago, the ECB unveiled its new anti-crisis weapon, the so-called OMT bond-purchase programme, aimed at helping out the region's most debt-wracked countries.
The scheme seems to have succeeded so far in bringing down borrowing costs of countries such as Spain without a single bond being bought.
And experts believe that with the feel-good effects showing no sign of fading just yet, the ECB is unlikely to put it into action.