China Unicom has stopped taking orders for the iPhone 4 after being swamped by customers seeking the new phone when it went on sale at the weekend.
Unicom had received orders for 200,000 phones by Saturday morning when the device went on sale, and sold 40,000 phones with contracts units on the first day, according to Chinese media reports.
Last year Unicom, the sole official supplier of the popular smartphone, took nearly six weeks to the sell the first 100,000 iPhones.
Apple told WSJ that it would be shipping extra iPhones to Unicom soon.
AT&T and other operators experienced similar shortages when they launched the iPhone 4 earlier this year.
Apple is now shortening the delays on introducing the iPhone to markets outside the US, and is ramping up its China sales operations by opening of dozens of Apple stores in the country.
Unicom’s prices start from 226 yuan (€25) a month for an 8GB phone with a two-year contract, and run up to 386 yuan for a 32GB device. Without contracts, the 16GB phone sells for 2,999 yuan and the 32GB for 4,799.