Lehman Brothers has boosted access to its own “dark liquidity” pool – offers to buy and sell shares that are hidden from the market – by installing an electronic access connection that is capable of linking with most order execution management systems.

Known as Liquidity Cross (LX), it is one of a growing number of such facilities offered by the largest investment banks seeking to capture the growing demand from investors to buy and sell large blocks of shares without causing prices to jump or fall in response.