Baumann, 58, had served as Freddie Mac's CFO since June 2003, leading the completion of the government-sponsored company's earnings restatement and subsequent improvements in its financial reporting. Prior to his work at Freddie Mac, Baumann spent 30 years with accounting firm PricewaterhouseCoopers, where he served as deputy chairman of the World Financial Services Practice.

In his new role, Baumann will manage the monitoring and analysis of accounting and auditing principles and related regulatory changes that impact specific companies and industries, according to Phil Wedemeyer, director of the PCAOB's office of research and analysis.

"My decision to join the PCAOB reflects my view of the importance of the integrity of financial reporting to our capital markets," said Baumann. "I was committed to that for over 30 years at PwC, and I joined Freddie Mac to restore accuracy, integrity and reliability to its financial reporting. The PCAOB gives me an opportunity to meld that experience with public service."