WASHINGTON —  An Ohio congressman and longtime critic of FirstEnergy Corp. (search), the Ohio-based utility at the center of the investigation into last week's blackout, wants the company's operating license revoked.

Rep. Dennis Kucinich (search), a Democratic presidential contender, will petition the Public Utilities Commission of Ohio to revoke FirstEnergy's right to operate in Ohio, spokesman Doug Gordon said.

Kucinich would release the petition at a news conference in Cleveland on Wednesday afternoon, Gordon said. A copy of the complaint was not immediately available, but it was related to "mismanagement and a climate of putting profit above the public interest," a release on the news event said.

Last week's blackout (search) left 50 million people from the Midwest to the Northeast in the dark. Experts have said the outage appears to have started on the northeast Ohio power grid owned by FirstEnergy, which has 4.3 million customers in Ohio, New Jersey and Pennsylvania.

FirstEnergy spokesman Ralph DiNicola said the company is assisting Energy Secretary Spencer Abraham (search) and his Canadian counterpart, who are heading a U.S.-Canadian task force investigating the blackout.

"As far as presupposing the outcome of that study, we think that would be speculative and irresponsible," DiNicola said of Kucinich's petition.

Shana Gerber, a spokeswoman for the Public Utilities Commission of Ohio (search), declined to comment on the petition until after it's filed.

Kucinich, who represents Cleveland, has clashed with FirstEnergy before.

He filed a petition in February with the Nuclear Regulatory Commission (search) to revoke FirstEnergy's authority to operate an Ohio nuclear plant damaged by an acid leak.

The Davis-Besse nuclear plant (search) near Toledo has been shut down since February 2002, when it was closed for maintenance. In March 2002, leaks were discovered that had allowed boric acid to eat nearly through the 6-inch-thick steel cap that covers the reactor vessel.

He also fought with power companies when he was mayor of Cleveland in the 1970s. Kucinich refused to sell the city's municipal electrical system to a utility now owned by FirstEnergy, and the city was plunged into deficit.

Kucinich barely survived a recall, and he lost re-election the following year to Republican George Voinovich, now a U.S. senator.

Cleveland officials now say Kucinich's decision saves consumers money in electricity rates.