The US Federal Energy Regulatory Commission (FERC) has provisionally fined the bank $435m and ordered it to repay $34.9m in “unjust profits”.

It accused the lender of engaging in a “coordinated scheme to manipulate trading at four electricity trading points in the western US”.

Four Barclays traders, including Scott Connelly, manning director of North American power at Barclays, were named and fined a total of $18m for their role, the paper reported.

Barclays said it would fight the allegations “vigorously”.

The bank said in its interim results yesterday that it was the subject of two new US investigations, one focusing on power trading activities in the US and the other centring on its relationship with third parties who help or assist it in winning new business.