WASHINGTON -- Nancy Killefer, who failed for a year and a half to pay employment taxes on household help, has withdrawn her candidacy to be the first chief performance officer for the federal government, the White House said Tuesday.

Killefer was the second major Obama administration nominee to withdraw and the third to have tax problems complicate their nomination after President Barack Obama announced their selection.

"Nancy Killefer has decided to withdraw her nomination, and we accepted her withdrawal," Tommy Vietor, a White House spokesman, said Tuesday. The 55-year-old executive with consulting giant McKinsey & Co., was expected to explain her reasons for pulling out later in the day.

When her selection was announced by Obama on Jan. 7, The Associated Press disclosed that in 2005 the District of Columbia government had filed a $946.69 tax lien on her home for failure to pay unemployment compensation tax on household help.

Since then, administration officials refused to answer questions about the tax error, which she resolved five months after the lien was filed. Obama's first choice for commerce secretary, New Mexico Gov. Bill Richardson, took his name out of consideration when his confirmation appeared headed toward complications because of a grand jury investigation over how state contracts were issued to political donors.

More recently, Timothy Geithner was confirmed as Treasury secretary despite belatedly paying $34,000 in income taxes, and Tom Daschle is still waiting to see if his late payment of more than $128,000 in income taxes will harm his nomination to be health and human services secretary.

On paper, Killefer brought impressive credentials to the two jobs Obama selected her for: deputy director for management at the Office of Management and Budget, which requires Senate confirmation, and a new White House post, chief performance officer for the entire federal government, which does not require confirmation.

Killefer oversees McKinsey's management consulting for government clients. During 1997-2000 in the Clinton administration, Killefer was assistant Treasury secretary for management. As such she was the chief financial officer and chief operating officer for the Treasury and its 160,000 employees and led a modernization of its largest component, the Internal Revenue Service.

But for nearly a month, the administration had refused to answer how its choice to make government workers more efficient and more responsive had bungled her household payroll taxes.

The AP reported that on March 7, 2005, the D.C. Department of Employment Services slapped a tax lien on her home in the tony Wesley Heights neighborhood. The local government alleged that just three years after she left the high-powered Treasury post she began to fail to pay unemployment compensation tax for a household employee. And she failed to make the required quarterly payments for a year and half, whereupon a lien for $946.69 was placed on her home.

That sum included $298 in unpaid taxes, $48.69 in interest and $600 in penalties. The lien was filed March 7, 2005, but Killefer didn't get the lien extinguished for almost five months, not until July 29.

During that period, Killefer and her husband, an economics professor, had a teenage son and daughter, but she had two nannies and a personal assistant to run her life when she was on the road, she told Harvard business students back then.