Monthly 3G subscriber growth in China has dropped sharply just before Apple kicks off wider iPhone distribution in the country thanks to its deal with China Mobile, the largest wireless operator in the country (and the world). In September, 17 million 3G subscriptions were activated in China. That figure tumbled to 13.4 million in October and 11 million in November. 3G subscriptions are a fairly good proxy for smartphone contracts in China; 2G subscribers still buy feature phones.

Apple started selling iPhone through two of China’s smaller challenger operators (China Unicom and China Telecom) in September. In early 2014, China Mobile will unleash the iPhone 5s and iPhone 5c to its 700 million subscribers.

The Chinese 3G slowdown could be a bitter pill for Apple’s rivals. The iPhone’s market share is clearly set to grow in China during the first half of 2014 — now brands ranging from Samsung to HTC and Nokia will also face a simultaneous decline of the pool of new subscribers buying first smartphones.