Seeing that demand for the iPhone 6 Plus is much stronger than expected, Apple has already adjusted its supply ratio for the two new smartphones, according to sources from the upstream supply chain.

But the retail channel is unlikely to feel any immediate changes since it normally will take a while for adjustments on the production side to start affecting the retail, the sources said.

The sources pointed out that the iPhone 6's shipments in the second half are expected to be 3-4 million units lower than the original expectation, as the supply chain gradually shifts some of its iPhone 6 capacity for production of the iPhone 6 Plus.

But most component suppliers' current inventories are not sufficient for extra iPhone 6 Plus orders, and device manufacturers also do not have sufficient production lines for related assembly. Therefore, the retail channel may need to wait a while before seeing a signifciant increase in iPhone 6 Plus supply, the sources noted.

The iPhone 6 and 6 Plus will also become available in China on October 17 and pre-orders from the country has already surpassed two million units.