Swiss bank UBS has admitted that its investment banking arm has lost around $2bn (£1.27bn) through “unauthorised trading”. Shares in UBS fell by almost 10% in early trading after it reported the loss, which could push the bank into the red for the current financial quarter. In a brief statement, issued on the third anniversary of Lehman Brothers, UBS said that the issue was still being investigated. “UBS has discovered a loss due to unauthorized trading by a trader in its Investment Bank. The matter is still being investigated, but UBS’s current estimate of the loss on the trades is in the range of $2bn. It is possible that this could lead UBS to report a loss for the third quarter of 2011. UBS added that “no client positions were affected.” Simon Ballard, senior credit strategist at RBS capital markets, said the trading loss would add to public concern over the banking sector . “At a time of greater regulation, it will raise questions about regulatory capital and whether ringfences are in place to stop this happening,” Ballard told Bloomberg TV. More details soon UBS Banking European banks Switzerland Europe Graeme Wearden guardian.co.uk