Facebook last month announced its program for news on smartphones, Instant Articles, will be available to all publishers after initially being available to a select group. Google unveiled a competing newsreader last month and announced partnerships with many of the same publishers.
Until now, Apple News included articles from a select group of more than 100 media outlets -- including ESPN, the New York Times, the Atlantic and Bloomberg -- starting in the U.S. Stories are curated based on the topics and outlets selected by the reader.
Apple will give publishers accurate reader metrics and analytics by integrating the app with ComScore, the industry standard for measuring Web traffic.
Publishers will keep 100 percent of the advertising revenue they sell inside the app while Apple will take a 30 percent cut from ads that it sells, according to reports.