Bradley bought the 162-year-old, Boston-based magazine in 1999 and moved it to Washington, where he and his wife Katherine are famous for entertaining the political and media elite in their Embassy Row mansion. He hosts a party the night before the White House Correspondents’ Dinner and recently feted former Atlantic president Bob Cohn, whose departure this fall signaled the changes to come.

The Wednesday memo provides clarity that current and former Atlantic staffers say has been lacking since the July 2017 announcement of the sale to Powell Jobs’s Emerson Collective and following Cohn’s departure in September without a permanent replacement.

Bradley, it was said at the time of the sale, would continue as chairman and operating partner for three to five years and that Emerson, which bought a 70 percent stake of the magazine more than $100 million, would “most likely assume full ownership of The Atlantic within five years.”

In Wednesday’s memo, Bradley said his minority ownership of The Atlantic would continue for at least five years from the date of the 2017 sale, “but maybe longer.” Bradley characterized his partnership with Powell Jobs as “uncommonly happy” and a “pure privilege.”

Bradley, 67, has lightened both his media and real estate portfolio in recent years. He unloaded the Watergate 600 building, which remains home to The Atlantic’s offices, in 2017 for $135 million; he sold Atlantic Media’s business news startup Quartz last year for a reported $75 million to $110 million.

Bradley has said his children are not interested in taking over the media business and so it remains to be seen how long he keeps National Journal, which has shifted from a politics and policy magazine to more of a consulting business with an editorial component, and Government Executive. In seeking out a steward for The Atlantic, Bradley said in 2017, he compiled a list of 600 potential investors but only approached Powell Jobs.

Meanwhile, Powell Jobs has been expanding her media portfolio through Emerson, which takes its name from famed writer Ralph Waldo Emerson (who also happens to be one of The Atlantic’s founders). Emerson has invested in media start-ups such as Axios and OZY Media and film and TV production company Anonymous Content. It has also provided grants to nonprofit newsrooms, such ProPublica and The Marshall Project, and advocacy groups like the Committee to Protect Journalists.

Powell Jobs, who invests in various civic and philanthropic organizations, isn’t overseeing The Atlantic day-to-day and has seldom been seen by staffers. She is said to communicate most with Bradley, editor-in-chief Jeffrey Goldberg and Peter Lattman, a former New York Times editor who heads up Emerson’s media investments.

But Powell Jobs’s presence at The Atlantic has been felt by an influx of resources since she arrived, with the company adding more than 100 employees — of which 50 are in the newsroom — launching a paywall, and unveiling a new redesign. The magazine on Friday added Pulitzer Prize-winning Washington Post columnist Anne Applebaum, who joins other post-sale recruits like George Packer, Peter Nicholas, Jemele Hill, Prashant Rao, and Dante Ramos.

The rapid expansion has led The Atlantic, which had been profitable, to now losing money, the Wall Street Journal reported in August. There has also been noticeable churn, with the departures of politics editor Vernon Loeb and writers like Julia Ioffe, Rosie Gray, Natasha Bertrand, Taylor Lorenz, and Elaina Plott — the latter announcing Friday she was joining The New York Times.

The Atlantic suffered a major blow last year when award-winning journalist Ta-Nehisi Coates exited the magazine a couple months after being pulled into a controversy involving the hiring and firing of conservative writer Kevin Williamson. Coates said upon leaving that he didn’t want to be “the public face of the magazine.”

There have also been several business-side departures in recent months, such as senior VP of global communications Emily Lenzner, chief business and product officer Alex Hardiman, and Cohn, who is currently on a short-term Harvard fellowship. The Atlantic didn’t fill Cohn’s position, though Atlantic Media president Michael Finnegan and Atlantic chief operating officer Aretae Wyler took on his duties.

Bradley wrote Wednesday that an executive search firm has begun a “thorough and ambitious” search for a new Atlantic leader, who may hold the title of president or CEO. The new president/CEO will report to ownership: Powell Jobs as majority owner and, for at least the coming years, Bradley as a minority stakeholder.

“The person will need to like, even love, the exquisitely hard work of media strategy, but appreciate that our purpose in being — for 162 years — is journalism, and its pursuit of truth,” Bradley wrote, adding that the “right person will model our central value of a spirit of generosity.”

So far, Bradley said, they have seen about 40 advisors and candidates for the position, which includes “current media leaders,” “editorial leaders making ‘the jump’ to business leadership,” “digital and product leaders,” and “rising stars from other industries.”

The hiring process, he wrote, “goes on until we find that uncommon talent that, as best we understand, is made to lead The Atlantic.”

And after he eventually sells his stake in the company, Bradley wrote, “Laurene shall own The Atlantic something like forever.”