WASHINGTON -- Jay Carney, the journalist-turned-press-aide who jousted daily with his former colleagues over issues from the Benghazi terrorist attack to the glitch-ridden health care website, stepped down as the White House press secretary Friday.

President Barack Obama interrupted Mr. Carney's regular briefing to deliver the news, announcing that Mr. Carney would be replaced by his deputy, Josh Earnest, whose ties to Mr. Obama date to the 2008 presidential campaign, in which Mr. Earnest served as the communications director in Iowa.

"Jay has become one of my closest friends and is a great press secretary and a great adviser," Mr. Obama said, as Mr. Carney yielded the podium. "He's got good judgment, he has good temperament, and he's got a good heart. And I'm going to miss him a lot."

In an interview, Mr. Carney, 49, said he was leaving after more than three years in the job -- and more than five years in the administration -- to devote more time to his family.

Friends of Mr. Carney said he also wanted to return to the private sector for financial reasons. He and his wife, Claire Shipman, a writer and part-time contributor to ABC News, have a 12-year-old son and a 9-year-old daughter, both in private school in Washington.

"I've been pretty cavalier at times about leaving to see my kid play in a game or to go to a parent-teacher conference," Mr. Carney said. "But 5 1/2 years is about what I could ask."

The president said Mr. Carney first brought up his departure in April. The timing of Friday's announcement -- hours after embattled Veterans Affairs Secretary Eric Shinseki submitted his resignation -- was dictated in part by the White House's decision to send Mr. Earnest on the president's trip to Europe next week.

Mr. Obama referred to his "incredible history" with Mr. Earnest, 39, and said his last name "describes his demeanor." Colleagues called Mr. Earnest even-tempered and disciplined. He has raised his profile as the narrator of "West Wing Week," a weekly online video diary that chronicles doings around the White House.

Mr. Earnest was one of two top candidates for the job, along with Jen Psaki, who was campaign press secretary for Mr. Obama in 2012 and is now the State Department spokeswoman. The White House decided to keep Ms. Psaki there, people with knowledge of the process said, because she has close ties with Secretary of State John Kerry.

The choice of Mr. Carney as press secretary put a seasoned White House correspondent on the other side of the cameras. A 21-year veteran of Time magazine, Mr. Carney proved to be a fierce advocate for the administration -- first for Vice President Joe Biden, for whom he was communications director, and then for the president.

While Mr. Carney was not part of Mr. Obama's inner circle, he developed an easy rapport with the president, even playing cards on Air Force One. David Axelrod, a former political adviser to the president, described Mr. Carney as a "consummate professional, smart and unflappable."

Though Mr. Carney often frustrated reporters -- he said he appreciated tough questions, while referring the questioner to other government agencies -- he rarely made a gaffe.

"Journalists have not made the best press secretaries, but Jay has shown respect for reporters and their professional needs," said longtime White House correspondent Ann Compton of ABC News. But Ms. Compton said she was concerned about the White House press office's practice -- intensified during Mr. Carney's tenure -- of posting its own photos, video and Twitter posts about the president's activities, while restricting access to the press corps.

Mr. Carney raised eyebrows recently when he appeared in a feature article in Washingtonian Mom magazine to promote a book on the work-family balance of which Ms. Shipman was an author. In one photo, Mr. Carney play-acted standing behind a lectern, taking questions from his children.

On Friday, reporters mixed good wishes for Mr. Carney with questions about why the White House did not disclose Mr. Obama's lunch the previous day with former Secretary of State Hillary Rodham Clinton. "It was just lunch," he replied.