A top executive at government-controlled mortgage giant Freddie Mac is leaving the company about a year after he was promoted to oversee its single-family mortgage business.

Anthony Renzi resigned to accept a job with another financial company, Freddie CEO Edward Haldeman said Monday in an internal email. The other company wasn't named. Renzi's departure as executive vice president of single-family business and operations and technology takes effect next month.

The move is the latest in a series of departures of top executives from McLean, Va.-based Freddie and its larger sibling Fannie Mae, which were rescued by the government in September 2008 after massive losses on risky mortgages threatened to topple them. Taxpayers have spent about $170 billion to rescue the companies _ the most expensive bailout of the financial crisis. It could cost nearly $200 billion more to support the companies through 2014 after subtracting dividend payments, according to the government.

CEO Haldeman plans to leave this year as well.

Haldeman acknowledged in the email that Renzi's resignation "comes at a pivotal time in Freddie Mac's executive leadership transition." The company expects to announce appointment of a new CEO "very shortly," he said.

The Associated Press obtained a copy of Haldeman's email to review. The Wall Street Journal reported Renzi's resignation on Monday.

Paul Mullings, a senior vice president at the company, will assume Renzi's responsibilities on an interim basis.

Freddie and Washington-based Fannie buy home loans from banks and other lenders, package them into bonds with a guarantee against default and sell them to investors around the world. The companies together own or guarantee about half of all U.S. mortgages, or nearly 31 million home loans worth more than $5 trillion. Along with other federal agencies, they backed nearly 90 percent of new mortgages over the past year.

In December the Securities and Exchange Commission filed civil fraud charges against former Freddie CEO Richard Syron and former Fannie CEO Daniel Mudd, as well as four other top executives who worked at the companies. The executives were accused of understating the level of high-risk subprime mortgages that Freddie and Fannie held just before the housing bubble burst in 2007. The executives have denied wrongdoing.

The government said last month it will cap pay for Freddie and Fannie chief executives at $500,000 per year and eliminate annual bonuses for all employees. Those changes came after Congress pressured the government to stop big payouts at the bailed-out companies.

The federal agency that oversees Freddie and Fannie also said it would cut pay for about 50 other executives at the two companies. Those employees are still eligible to earn salaries above the cap.

Previously, Renzi was Freddie's executive vice president of single-family portfolio management, which oversees the company's mortgage servicing business and other units.

He joined the company in April 2010 after working as chief operating officer of GMAC Residential Capital and president of GMAC Mortgage.