Obama praised Eggleston's "extraordinary expertise, credentials and experience."
"He has a passion for public service, is renowned for his conscientiousness and foresight, and I look forward to working closely with him in the coming years," Obama said in a statement.
Obama had warm words for Ruemmler, who has planned to leave the White House for several months, calling her a valued friend and trusted adviser who had an "uncanny ability to see around the corners that nobody else in the room anticipates."
Eggleston is a partner at Kirkland & Ellis, one of the nation's biggest corporate law firms, where he advises corporations on issues ranging from corporate governance to internal investigations to allegations of fraud. He has represented individuals and companies facing criminal, congressional or regulatory investigations.
In choosing Eggleston, Obama is picking a lawyer familiar with the type of congressional confrontations the White House is likely to face in the last years of Obama's presidency. Obama has already faced aggressive inquiries from congressional investigators in the Republican controlled House, from the attack on the American consulate in Benghazi, Libya, to accusations that the Internal Revenue Service improperly scrutinized conservative non-profit groups. A Republican takeover of the Senate in this year's mid-term elections would likely increase such inquiries.
His private sector work has also focused on helping companies navigate regulations imposed by Obama's own administration. When he joined Kirkland & Ellis in 2012, Jeffrey Hammes, chairman of Kirkland's global management executive committee, said Eggleston was joining the firms "at a time when increased government scrutiny and regulation, and the successes of our white collar practice, continue to increase demand for our experienced white collar and securities enforcement attorneys."
In 2009, Eggleston represented then Obama chief of staff Rahm Emanuel during the prosecution of former Illinois Gov. Rod Blagojevich on charges of corruption, including seeking to exchange an appointment to Obama's old Senate seat for campaign cash or a job.
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