Apple struck a licensing deal Sunday with both Warner Music Group and its publishing arm, Warner Chappell, bringing Apple’s free Internet radio product that much closer to launching, according to sources familiar with the negotiations. The deal suggests that Apple is working hard to unveil what’s been dubbed iRadio at its Worldwide Developers Conference, which begins June 10. Apple spokesman Tom Neumayr declined to comment. Warner is the first of the major labels to reach deals for both recorded music and publishing, sources say. Apple last month reached a deal to license music from Universal Music, the world’s largest label, and negotiations are still going on with Sony, which has been going back and forth with Apple over some specifics about features built into Apple’s product. The deals reached so far offer far better economics for the music labels and publishers than what they get from Pandora, the product that most closely resembles iRadio.