Apple finally unveiled iTunes Radio back at its Worldwide Developers Conference in June after months (if not years) of rumors that the company would launch such a service. At the time, Apple did not give a release date, but said it would be generally available this fall.

We’re getting closer. We still don’t have an official date, but a report out from AdAge says it’s coming in September, citing people familiar with advertiser negotiations. Launch partners, the report says, will include McDonald’s, Nissan, Pepsi, Procter & Gamble and possibly a couple others. The deals range from “the high single-digit millions of dollars to tens of millions of dollars, and include a 12 month ad campaign,” it says.

Apple will hold an event on September 10th, when the next iPhone (or iPhones) is expected to be revealed. It’s likely that iTunes Radio’s launch will also be announced.

iTunes Radio will debut with over 200 stations and a catalog of music drawing from the iTunes Store. People can listen to stations, then download the songs if they like them. It can be used from an iPhone, iPad, iPod Touch, Mac, PC or Apple TV. It will include stations inspired by music users have already listened to, as well as stations curated by Apple and personalized genre-focused stations. Users will be able to create new stations based on specific songs.

The service will also provide exclusive premieres from top-selling artists, and will host special events like live streams from the iTunes Festival and other exclusive iTunes sessions.

It will also be integrated with Siri. You’ll be able to give it commands like “play more like this” or “play jazz radio” or ask who plays a particular song.

The service is free, hence the ads. iTunes Match users will get the service with them.