We've been following Apple's big breakthrough into China very closely, and heard just yesterday about rumours of a deal being reached between Cupertino and the country's second largest network provider China Unicom.

TechCrunch reports that a deal has now been finalised and announced, with both Apple and China Unicom in attendance.

The deal will see the iPhone launched in the fourth quarter of 2009 as part of a three year agreement. The good news for China's technophiles is that both the 8GB and 16GB models will be made available, along with both memory capacities (16GB and 32GB) of the improved iPhone 3GS.

The major question hanging over the Chinese iPhone is how wide your applications and games will be made available, given that wi-fi is to be disabled on all models. According to China Unicom's chairman Chang Xiao Bing, the company will launch its own version of the App Store, which will also include applications of Google's Android platform.

Presumably this custom application store won't include the 10MB over-the-air download limit, though it is unclear whether the current worldwide back catalogue will be made available to Chinese gamers at launch.