Customers look at iPhone devices at a store in Xuchang, Henan province. China Mobile began to take preorders for the iPhone 6, to be released by Apple Inc on Sept 9 in San Francisco. XU ZHONGYUAN/CHINA DAILY

Try not to have a party before payday this month. You may need money earlier than you thought if you want to show off that new iPhone 6 to your colleagues.

On Tuesday, a week before Apple Inc is set to unveil its next-generation smartphone, China Mobile Ltd - the world's biggest telecom carrier by subscriber number - kicked off online preorders for the widely anticipated device.

China Mobile's preorder campaign also confirmed rumors that Apple will release larger screens for the device as buyers are asked to choose either a 4.7-inch version or a 5.5-inch one. The iPhone 5S has a 4-inch screen.

The program is available only in Beijing and, as of Tuesday evening, had attracted more than 33,000 orders. It remains unclear when the buyers can get the device. A person familiar with the matter told China Daily the first iPhone 6 could be distributed to Chinese customers as early as mid-month.

China Mobile did not disclose whether the preorder would be expanded to the rest of the nation. Apple is slated to unveil the devices on Sept 9 in San Francisco.

Online reservations are the usual way that Apple enthusiasts on the Chinese mainland get the first batch of iPhones. On Taobao, the largest consumer-to-consumer e-commerce platform in China, hundreds of stores that are receiving the iPhone 6 are asking for a down payment of about 5,000 yuan ($810).

"Many people are asking about the iPhone 6, but only a few have paid the preorder fee," said Li Lijun, an electronics seller on Taobao. A total of 16 people had ordered the device from him since July.

Significantly fewer people are opting to book iPhones from unofficial dealers this year as opposed to several years ago because Apple products now become available on the Chinese mainland shortly after the worldwide launch.

The top Taobao shops each gathered roughly 200 preorders this year, compared with the iPhone 5 release, when some stores received about 700 preorders, according to Li.

Apple dropped to sixth place in market share among smartphone vendors in China in the second quarter of this year, according to data from industry researcher IDC.

Its quarterly shipments were on par with second-tier local makers such as vivo Communication Technology Co Ltd and OPPO Electronics Corp, said IDC.

Sales of iPhones in China are predicted to face stiff competition from domestic smartphone vendors Xiaomi Corp and Lenovo Group Ltd as they release their flagship devices.

On the same day that China Mobile started its reservation service for the iPhone 6, Chinese company Meizu Telecom Equipment Co Ltd introduced its latest smartphone in Beijing.

Meizu, a niche player, is said to be planning 1,000 brick-and-mortar retail outlets in the country, challenging Apple and Xiaomi.