* 668,000 customers switched during the month, the highest monthly switching figure recorded, despite February being the shortest month of the year.

* The data comes as Britain's energy firms are under pressure to reduce bills and as regulator Ofgem prepares to issue a price cap on the most widely used tariffs.

*It also continues last year's trend when a record 5.5 million customers switched in 2017 up from 4.8 million in 2016, Energy UK said.

*The data does not show exactly which companies gained or lost customers but shows almost half the switches were between large suppliers, while almost a quarter of switches were from larger firms to smaller suppliers.

*There are now over 60 energy suppliers in Britain.

*Britain's big six energy suppliers, controlling around 80 percent of the market are Centrica British Gas, SSE (>> Scottish and Southern Energy), E.ON, EDF Energy (>> Electricité de France), Innogy's (>> innogy SE) Npower and Iberdrola Scottish Power.

(Reporting By Susanna Twidale, editing by David Evans)