Transatlantic exchange group NYSE Euronext has won regulatory approval to launch an anonymous trading system, or “dark pool”, in partnership with a US rival, in the latest sign that traditional exchanges are reaching out to new trading systems to maintain equity volumes.

NYSE Euronext and Bids Trading will launch the system, known as the New York Block Exchange, on Thursday, some three months later than planned, the companies said in a statement. It will be open to all NYSE members and Bids clients, and will match large orders by searching its own anonymous system as well as the New York Stock Exchange's order book.