Deborah Platt Majoras, chairwoman of the Federal Trade Commission (FTC) since 2004 and a champion of identity theft protection for consumers, announced Thursday that she plans to leave her post in late March.

In a statement, Majoras did not say why she was leaving or what her next job would be. No successor was named.

"The FTC plays a vital role in standing up for consumer interests and a competitive marketplace," she said. "Tough, yet well-reasoned, anti-trust and consumer protection enforcement is a powerful combination that provides a strong foundation for our nation's economic system."

Majoras, named one of SC Magazine's Top 5 Influential Security Thinkers in 2006, established the FTC's Division of Privacy and Information Protection and served as co-chair of the President's Identity Theft Task Force.

Under her leadership, the FTC unveiled its "AvoID Theft: Deter, Detect and Defend" program, which sought to raise awareness about the risks of identity theft and serve as a resource for victims.

She oversaw a number of lawsuits against purveyors of spam and spyware. In addition, she targeted  corporations, such as ChoicePoint, which failed to implement proper data security controls and suffered a breach as a result.