Barclays PLC and four former traders must pay a combined $487.9 million in fines and penalties, the U.S. Federal Energy Regulatory Commission said in an order tied to an investigation of alleged manipulation of energy markets.

The agency directed the company and traders to pay $453 million in civil penalties to the U.S. Treasury within 30 days, according to an order issued Tuesday. The London-based bank must also give up $34.9 million in profits, to be distributed to programs that help low-income homeowners pay energy bills in California, Arizona, Oregon and Washington, it said.