LONDON - The euro remained vulnerable in volatile trading conditions on Thursday as uncertainty over unity in the euro zone weighed on the single currency, with extreme short positioning exacerbating moves. Higher-yielding currencies such as the Australian dollar were under heavy selling pressure as the euro zone's troubles fuelled risk-aversion, knocking equity markets and commodities, forcing liquidation of long positions. At 0735 GMT, the euro was trading down 0.2 percent at $1.2410 in choppy trading conditions after falling in Asia to $1.2323. Traders noted good interest to sell rallies above $1.2400. It had rebounded from a four-year low of $1.2143 on Wednesday as traders covered short positions on speculation European monetary officials might move to check its rapid fall. A European Central Bank spokesman declined comment on the market rumours and Eurogroup Chairman Jean-Claude Juncker said in Tokyo on Thursday he did not see a need to take immediate action. "The bias for the euro is still lower but concerns over excessive short positioning mean the price action will be very volatile," said Geoffrey Yu, currency analyst at UBS. Increased uncertainty over market regulation in the euro zone was the latest negative for the euro. Germany's unilateral ban of naked short-selling in euro zone bonds and some bank shares caught its European partners unawares, suggesting the bloc was unable to form a united front in addressing its debt crisis. A German parliamentary vote on a 750 billion euro rescue package to stabilise euro zone bond markets was adding to uncertainty.
