UPDATE 1-Lacking a lifeline, Exelon's Illinois nuclear plants to retire in fall -CEO

(Adds detail on fossil plants in Illinois)

Aug 4 (Reuters) - U.S. energy company Exelon Corp said on Wednesday it still plans to retire uneconomic nuclear reactors at Byron and Dresden in Illinois this autumn unless some state or federal program is passed to save the plants.

Exelon Chief Executive Christopher Crane said in an earnings release that the company remains "hopeful that a state solution will pass in time to save the plants," but noted "clean energy legislation in Illinois remains caught in negotiations over unrelated policy matters."

Those unrelated matters include a disagreement over retirement of fossil plants owned by others.

Separately, there is also lingering public and political anger at Exelon's Commonwealth Edison unit after the Chicago-based utility agreed to pay $200 million to resolve a U.S. Justice Department probe over inappropriate lobbying practices in 2020.

Unless something changes, Exelon plans to shut the 2,300-megawatt (MW) Bryon in September and the 1,797-MW Dresden in November. One megawatt can power about 1,000 U.S. homes.

As for help from the federal government, Crane said "passage of legislation remains uncertain and, regardless, will come too late to save our Byron and Dresden plants."

After closing at its highest since February 2020 on Tuesday, Exelon shares were down 1.8%.

Exelon has blamed the planned nuclear shutdowns on market rules that it said favor fossil-fired and renewable plants over carbon-free nuclear energy.

Exelon has said Dresden and Byron face revenue shortfalls in the hundreds of millions of dollars and together employ more than 1,500 workers.

In 2016, Exelon, which operates six nuclear plants in Illinois, won state subsidies that analysts have said provide about $230 million a year to keep its Clinton and Quad Cities plants operating.

Exelon, however, has long sought subsidies for its other Illinois nuclear plants.

Exelon has been successful in winning subsidies in New York and New Jersey to keep reactors operating to help meet those states' clean energy goals.

But when states do not provide subsidies, the company has retired reactors like Three Mile Island in Pennsylvania in 2019.

(Reporting by Scott DiSavino; Editing by Marguerita Choy and Sonya Hepinstall)