Deutsche Börse will let members opt out of a block-trading partnership established with buyside-only trading venue Liquidnet last year, following concerns from brokers that the service could reveal sensitive trade information to the rest of the market.

Deutsche Börse connected its anonymous trading venue - or dark pool - to Liquidnet's block crossing system at the end of last July. The so-called Block Agent service enables German stock orders in Deutsche Börse's dark pool worth over €100,000 to interact with the orders on Liquidnet, whose members comprise institutional investors and hedge funds.