After months of speculation and allegedly delayed negotiations, Apple is reportedly making progress in licensing content for its iRadio, which could debut at WWDC 2013.

Apple's purported Internet radio service dubbed iRadio is expected to come as a Spotify challenger and some insiders believe the service could debut as soon as next week, at Apple's Worldwide Developers Conference (WWDC) 2013.

Citing people familiar with the ongoing negotiations, The New York Times (NYT) reports that Apple signed a deal with Warner Music Group this weekend, securing recorded music and music publishing rights. The new deal adds to an agreement that is already in place with Universal Music Group for recorded music, adds the NYT.

According to the NYT's sources, the Cupertino tech giant is gearing up to secure arrangements with some of the world's largest labels, including Warner, Universal and Sony, as part of a bid to unleash its new service at WWDC 2013. Apple's annual developer conference takes place next week from June 10-14 at the Moscone West in San Francisco.

The Wall Street Journal (WSJ), meanwhile, supports the same claims, citing its own sources. The WSJ reported that Apple inked a licensing deal with Warner Music Group on Sunday, June 2, obtaining the rights to Warner's recorded music and music publishing. Apple will reportedly give the label's publishing arm 10 percent of ad revenue, which, according to the publication, is more than double what Pandora gives major publishers. The WSJ points to the same WWDC timeframe for the iRadio debut.

"Apple has signed a deal with the Universal Music Group for its recorded music rights, but not for music publishing - the part of the business that deals with songwriting," the NYT clarifies. "Over the weekend, Apple also signed a deal with the Warner Music Group for both rights. It is still in talks with Sony Music Entertainment and Sony's separate publishing arm, Sony/ATV, whose songwriters include Taylor Swift and Lady Gaga."

"People familiar with the matter have said Apple's service would allow users to stream songs and be integrated with Apple iAd service, which allows developers to show ads within their apps," the WSJ further explains. "Apple remains a leader in music downloads but faces competition from Internet radio services like Pandora and subscription streaming services like Spotify AB."

In other words, Apple's Internet radio service is expected to be free and supported by advertising. With Warner Music Group and Universal Music Group on board, all that's missing is Sony to put the cherry on top. Apple's iRadio will, however, arrive quite late in this popular area of the music business. Pandora already amasses more than 70 million regular users, most of whom enjoy the service for free.

Spotify, Google and Clear Channel Communications already introduced similar offerings, so Apple will have some catching up to do. On the other hand, Apple is reportedly negotiating directly with the music groups because it wants to land more extensive licensing terms.