LOS ANGELES, June 20 (Reuters) - The state of Illinois has asked the U.S. federal regulator to take another look into whether Edison Mission Energy's trading behavior was unethical and whether its actions caused higher electricity bills for consumers, Illinois officials said on Friday.

The Federal Energy Regulatory Commission in May settled with Edison Mission after a two-year investigation. It found that the unit of Edison International (EIX.N: Quote, Profile, Research) did not cooperate with the FERC investigation of its power sales practices in the PJM Interconnection gird area, which covers 13 states.

Edison Mission last month agreed to pay $7 million in civil penalties for hindering the FERC investigation and also committed to developing a program to ensure compliance with market regulations, which is expected to cost about $2 million.

Illinois Attorney General Lisa Madigan's office on Thursday filed a motion calling for FERC to reopen the investigation into Edison Mission's trading behavior.

Illinois, along with power organizations in seven other states, asked FERC to reopen its investigation on the charges of marketing malfeasance by Edison Mission Energy in selling power into day-ahead and real-time power markets.

Susan Hedman, environment and energy counsel in the Illinois attorney general's office, said when the FERC order came out in May, she called cohorts in other states. She and her counterparts were dismayed that FERC only ruled on the method of reporting trading behavior by Edison Mission and did not address whether Edison Mission's practices were unlawful or unethical.

"That's one of the puzzling things about the FERC order," Hedman said.

FERC has 30 days to respond to the motions to reopen the investigation, said Barbara Connors, spokeswoman for FERC. She would not comment on claims that FERC ignored the core of the matter regarding Edison Mission market behavior.

Edison Mission sold power generated by another Edison International arm, Midwest Generation, which has about 6,000 megawatts of power generation units in Illinois.