Time Managing Editor Richard Stengel is leaving the magazine to join the U.S. State Department, a person familiar with his move confirmed Thursday evening.
Nancy Gibbs, Time's deputy managing editor, is expected to succeed at the magazine, a source said.
Spokesmen for Time and the State Department declined to comment.
Ms. Gibbs has been running the magazine since late July, when Mr. Stengel joined Martha Nelson, the editor-in-chief of Time Inc., in helping the company prepare for its separation from parent company Time Warner. Ms. Gibbs has lately overseen the hiring of 30 editorial staffers ahead of a web redesign scheduled for late October.
A joint report from Politico and Capital New York first reported the news of Mr. Stengel's departure, saying he will become under secretary of state for diplomacy and public affairs.
Mr. Stengel was named managing editor at Time in May 2006. But his new job at the State Department is not his first foray into government. In 1999, Mr. Stengel was a senior adviser and chief speechwriter for Bill Bradley's presidential run, according to the Time website.
Mr. Stengel's tenure atop Time saw both Newsweek and U.S. News & World Report abandon the once-fierce battle among print news weeklies, but the headwinds they faced buffeted Time as well. Its ad pages declined 17% in the first half of the year, compared with the period a year prior, after falling 12.2% in 2012, according to the Publishers Information Bureau.
Web traffic to Time.com is growing, reaching 10.1 million unique visitors in August, according to ComScore, up 15% from the August 2013 despite the presidential campaign then drawing readers to news coverage.
But the title's print circulation has declined. The magazine averaged paid and verified circulation of 3.3 million in the first half of the year, including single-copy sales of 58,462, according to its report with the Alliance for Audited Media. In the first half of 2006, it averaged nearly 4.1 million copies, including single-copy sales of 119,446.