Janet Rehnquist, under fire from members of Congress and government investigators for alleged professional misconduct, will resign her post as inspector general of the Department of Health and Human Services on June 1.

In a letter yesterday to President Bush, she said she is resigning to "spend more time with my teenage daughters and pursue other professional opportunities."

Rehnquist, daughter of Chief Justice William H. Rehnquist, has been embroiled in controversies since soon after taking over the IG job in August 2001.

HHS Secretary Tommy G. Thompson yesterday praised her "integrity, professionalism and intelligence," and credited her with saving $21 billion for taxpayers and improving collection of unpaid child support payments through her enforcement activities.

According to allegations under investigation by the General Accounting Office, Rehnquist intervened in one case at the behest of a friend even though the matter was outside her office's jurisdiction. Another complaint asserted she had pushed for quick settlement of a case involving false claims by a Pennsylvania hospital, after three Republican members of Congress wrote HHS that the federal action was "unwarranted and unfair."

Along with those concerns, the GAO was also evaluating reports that she kept an unauthorized gun in her office, destroyed documents relevant to the GAO probe, improperly fired government fraud investigators and delayed an audit of the state employees' pension fund in Florida, home state of Gov. Jeb Bush (R), brother of the president.

The GAO report, which is due later this month, was sought by Sens. Charles E. Grassley (R-Iowa) and Max Baucus (D-Mont.).

"This is the right step," Grassley said. "The inspector general job wasn't a good fit for her abilities. I certainly wish her well in her next position."

Some officials defended her before yesterday's announcement. "Her biggest problem is that her name is Rehnquist," Thomas Scully, administrator of the Centers for Medicare and Medicaid Services in HHS, told CNN, which first reported that her resignation was imminent. "She was an easy target. She's had a lot of people in her own agency taking shots at her."

In her job as IG, Rehnquist had key responsibility for rooting out fraud and abuse in the huge Medicare and Medicaid programs.

At the same time, however, she was dogged by charges that her own actions had cost the government hundreds of thousands of dollars.