Those looking to purchase an iPhone 6 in China will not be a part of the first wave of buyers around the world later on this month.

Though the two new smartphones will go on sale on Sept. 19 in the United States and other markets, Apple has not decided on a release date for China.

China is considered to be the world's biggest smartphone market, so it is odd Apple hasn't decided on a release date there yet.

The debut is a departure from 2013, when Apple released the iPhone 5S and 5C simultaneously in 11 countries and territories like the U.S., Hong Kong, Japan, and Germany. Most analysts predicted Apple would do the same for the iPhone 6 release.

It also comes after a 50-percent year-on-year rise in iPhone sales in China, which now carries Apple's fifth-generation phones on all three of its carriers, according to Reuters.

"China is a key market for us and we will get there as soon as possible," the Cupertino company said to Reuters about the release.

Chinese media has speculated that Apple hasn't received a routine certification from the Ministry of Industry and Information Technology (MIIT), which inspects new smartphones before they are allowed on Chinese carrier networks.

The ministry website didn't list the new iPhones as of Thursday.

If the certificate is the only issue, iPhone sales could begin as soon as they are approved.

Third-party sellers and sales representatives at China Mobile's Beijing branch said the launch date had been pushed back from when they previously expected.

Customer support representatives at China Mobile's Beijing subsidiary and a sales representative said this week they had received a notice saying that shipping for the iPhone 6 would begin at the end of 2014.

China Mobile has not commented on such a notice yet publicly. 

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