Instinet, the agency broker in which Reuters has a 63% stake, has been issued with two subpoenas by the Securities and Exchange Commission (SEC), which is investigating its new subsidiary, Island.

The subpoenas relate to Island's pricing structure towards its former parent company, Datek, which was given preferential treatment compared with other clients and non-members, according to the SEC. The regulator has also asked for more information regarding Island's policy on market data rebates.