One analyst predicts that Apple could sell as many as 40 million iPhones in China in 2013. Reported by AppleInsider, Morgan Stanley’s Katy Huberty issued a note to investors Sunday that touches on the “vast untapped potential” for the iPhone in China.

Apple CEO Tim Cook noted at last week's earnings call that China is an extremely important market for the company. They are continuing to invest heavily to increase its footprint in that market.

The popularity of the phone was so overwhelming that Apple had to halt the sales there. Huberty believes that if Apple is able to extend its China partnerships to include China Telecom, the company could sell an additional 26 million iPhone units in calendar year 2013. Making it 40 million in the entire region.

China Mobile already has nearly 10 million iPhone users on its network, despite not selling the phones through its channels — and even though iPhones on China Mobile don’t have access to 3G.

Graphs from Morgan Stanley