Nothing attracts news organizations like Facebook. And nothing makes them more nervous.

With 1.4 billion users, the social media site has become a vital source of traffic for publishers looking to reach an increasingly fragmented audience glued to smartphones. In recent months, Facebook has been quietly holding talks with at least half a dozen media companies about hosting their content inside Facebook rather than making users tap a link to go to an external site.

Such a plan would represent a leap of faith for news organizations accustomed to keeping their readers within their own ecosystems, as well as accumulating valuable data on them. Facebook has been trying to allay their fears, according to several of the people briefed on the talks, who spoke on condition of anonymity because they were bound by nondisclosure agreements.

Facebook intends to begin testing the new format in the next several months, according to two people with knowledge of the discussions. The initial partners are expected to be The New York Times, BuzzFeed and National Geographic, although others may be added since discussions are continuing. The Times and Facebook are moving closer to a firm deal, one person said.

To make the proposal more appealing to publishers, Facebook has discussed ways for publishers to make money from advertising that would run alongside the content.