iPhone sales may increase in China after Apple's partnership with China Mobile; however, an analyst suggests that the handset maker has missed the country's smartphone boom.

Apple recently announced that it has entered into a deal with China's biggest wireless carrier, China Mobile, which will start selling the latest iPhone 5s and the iPhone 5c from January 2014. The deal is expected to add around $10 billion to Apple's annual revenue. However, the company may have missed the bus.

According to data revealed by investment firm Wedge Partners' analyst Jun Zhang, 3G smartphone growth in China declined in the fourth quarter of this year.

The analyst said that the average 3G user growth in China, which currently supports most smartphone sales, declined from 17-18 million per month in Q3 2013 to 12.5-13 million per month in Q4. The figures indicate that the overall Q4 3G user growth will drop 26 to 28 percent by the end of the quarter when compared to Q3.

Zhang also said that the overall smartphone sales in China also dropped from 26-30 million per month in the August and September period to 20 million in October and then to 18-19 million in November. The data indicates that the overall smartphone sales will drop by around 25 percent in Q4.

"With slowing overall smartphone sales and the launch of Apple products in the latter part of September, it is not surprising that Apple's market share increased in October. We believe current iPhone 5s/5c sales are slowing down and the sale of iPhones in China were affected by slowing smartphone sell-through," per Zhang. "iPhone 5c was out of the top 20 smartphone sales list. iPhone 5s's No.2 place was replaced by Xiaomi. Xiaomi 3, Xiaomi Red and the latest launched Vivo 3 are among the top 5 smartphones on the sales list. No.3 is iPhone 5s."

China Mobile has an overall user base of 760 million subscribers, including 170 million 3G subscribers. Analysts estimate that Apple may be able to attract 17 million China Mobile 3G customers to buy the iPhones in 2014, which will generate additional revenue of $9 to $10 billion.

Chinese consumers will be able to buy iPhones from China Mobile from mid-January and Apple will hope that it can lure as many customers as possible to buy its latest smartphones.