China is Apple's (AAPL) fastest-growing region by far.

The company clocked record sales of $4.5 billion there, or 16% of the global total, in its most recent quarter. Revenue in China grew to $13 billion in fiscal 2011, up from about $3 billion, or 2% of total sales, in 2009.

The iPhone accounts for over half of Apple's stock price, according to Trefis analysis. And if Apple and China Mobile(CHL) sign a carrier contract giving Apple access to 650 million subscribers, this has the ability to move the stock. Currently, China Unicom(CHU) is the exclusive carrier for the iPhone in China.

See the full Trefis analysis of Apple here

Opening new stores & new carriers will increase penetration

Apple opened 30 new stores in the latest quarter, only nine of which were in the United States. The Hong Kong store, opened in the last weekend of the quarter, set a company record for the highest opening-day sales. 

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Greater China now has six Apple stores. The U.S. Apple stores have shown that these retail locations help better engage customers and sell more phones.

China Unicom's iPhone exclusivity on the mainland has been a boon to the mobile operator. However, China Mobile and Apple appear close to reaching a deal on its plans to carry the phone. The carrier is already selling and promoting the iPhone around Beijing in the hopes of signing up customers to its Wi-Fi plans in anticipation of a pending deal.

Once signed, the deal will be a huge boost to Apple as China Mobile is by far the biggest mobile operator with around 650 million subscribers. For perspective, China Mobile has a Trefis valuation of close to $230 billion while China Unicom's valuation is just over $50 billion, supported by its 170 million subscribers.

China presents tremendous growth

"We're really doing everything basically that we're doing in the United States, we're doing in China" - Tim Cook, Apple CEO

The company has plans for large scale expansion with significant investment in the country. It has left no stone unturned as it aims to expand both its online store and retail presence. Apple is also concentrating on building third-party channels and spends a significant amount on advertising for promotions in the country as Cook and crew see ample long opportunity for growth.

We currently have a price estimate of $502 for Apple's stock, which is about 20% above the current market price.

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