US high-frequency trading firms are turning to the UK for regulatory authorisation of their European businesses ahead of new rules that will force them to have a similar level of oversight to brokers and other investment firms.

Two prominent US HFT firms - XR Trading and Headlands Technologies - have received authorisation from the UK's Financial Conduct Authority in recent months, according to the UK's Financial Services Register. The firms have received proprietary trading licences, the records show, and are unable to hold client money.