After a failed effort to boost business that angered equity traders, Deutsche Börse AG, Europe's largest stock exchange by market value, will shorten trading hours on its electronic stock-trading system from November. Trading hours on Xetra, its electronic system, will be two and a half hours less than the current span of 9 a.m. to 5:30 p.m. local time, according to Frank Hartmann, an exchange spokesman, in a report by Bloomberg. The move will bring Xetra’s closing time into line with most other European exchanges. The trading hours were introduced in June 2000. Germany's banks and brokerages have opposed the longer hours since then, citing lack of interest among investors and the cost of keeping traders at work.