Sony has reportedly signed a deal with Apple for the iRadio service, bringing the last of the three major record labels on board days before WWDC. AllThingsD reported the news this morning, saying that Apple was now set to announce the news of iRadio on Monday; previous reports have said it will launch in the months after WWDC. Apple reached an agreement with Universal Music Group in May, and it brought Warner Music on board just a few days ago, but Sony has remained a holdout until now, allegedly because it wanted Apple to pay more than iRadio competitor Pandora.

Apple has had a long road to its subscription-based streaming music service, which is said to be supported by ads from a revamped iAd service. It's said to have clashed with music labels over terms, and some have apparently expressed concerns about Apple's ability to land big ad deals. Google also handily beat it to the subscription music game, announcing its Google Play Music All Access service last month. But Apple also has the weight of its ubiquitous iTunes service to buoy it — not to mention a far better name.

Update: The LA Times has also independently confirmed the news, saying that Apple is still in talks with publishing arm Sony / ATV but that it's not expected to delay the service's announcement or rollout.

Update 2: According to All Things D, Sony / ATV is now on board with iRadio as well. Peter Kafka tweets that the music publisher has signed a two-year deal that will reward it with 10 percent of ad revenue Apple makes from its song catalog.