Consumers in China, who represent an increasingly critical pillar of Apple Incs business, will not be able to buy the new iPhone 6 as part of the first wave of buyers around the world this month. Although the two new smartphone models will go on sale Sept 19 in the United States and other markets, Apple is yet to set a release date for China, the worlds biggest smartphone market. The staggered debut is a departure from one year ago, when Apple released the iPhone 5s and 5c simultaneously in 11 countries and territories including the United States, China, Hong Kong, Japan and Germany, a feat that was seen as setting a new standard for its supply chain and retail management. It also comes after a 50-percent year-on-year rise in iPhone sales in China, which now carries Apples fifth-generation phones on all of its three carriers, effectively salvaged an otherwise lacklustre second quarter for the Cupertino company.