BEIJING, May 5 (Xinhuanet) -- The top U.S. Environmental Protection Agency administrator in the Midwest resigned Thursday amid internal fights over dioxin contamination near Dow Chemical Co.'s world headquarters in Michigan, according to a published report.

    Mary Gade, regional administrator of EPA Region 5, told the Chicago Tribune she resigned as regional administrator of EPA Region 5 after two top EPA officials stripped her of her powers and told her to quit or be fired by June 1.

    "There is no question this is about Dow," Gade told the paper for a story on its website. "I stand behind what I did and what my staff did. I'm proud of what we did."

    Dow spokesman John Musser said Gade's departure came as a surprise. He said the chemical giant would rather work with the federal government than with Michigan officials, who have been designated by the agency to oversee future dioxin cleanup.

    "Flatly, we never asked or implied that Ms. Gade be removed from her post," Musser told The Associated Press in a telephone call late Thursday. "We have no idea what the EPA's reason was for this move."

    Lana Pollack, president of the Michigan Environmental Council, said that Dow and the EPA had "succeeded in muzzling a woman of unquestioned credentials and integrity who was doing her job enforcing our environmental laws."

    Jonathan Shradar, an EPA spokesman in Washington, told the Tribune Gade had been placed on administrative leave until June 1, but declined further comment. A woman who answered the telephone at Region 5 referred calls to Shradar, who was not immediately available.

    Gade is a former corporate attorney who led the Illinois EPA under Republican Gov. Jim Edgar. President Bush appointed her in 2006 to head the federal agency's Region 5, which covers the states of Illinois, Wisconsin, Minnesota, Indiana, Michigan, and Ohio.

    The company has acknowledged tainting the Tittabawassee and the adjoining Saginaw River, their flood plains, portions of the city of Midland and Lake Huron's Saginaw Bay with dioxins — chemical byproducts believed to cause cancer and damage reproductive and immune systems.

    (Agencies)