The operators of European dark pools are stepping up efforts to encourage larger institutional orders because forthcoming European Union caps on dark pool volumes will not apply to large trades.

Turquoise, the equity market majority-owned by the London Stock Exchange, on Monday started a new service to facilitate block trades. It is designed for institutional investors and allows Turquoise members to issue a "block indication", announcing interest in buying a large order of a given stock. If a matching block indication is found, the two parties are asked to complete the trade.