Pre-orders for Apple Inc's iPhone X are "off the charts", the company said on Friday, sending its shares up over 2 per cent.

Pre-orders for the much-anticipated 10th anniversary phone started from 12.01 am PT (0701 GMT) on Friday.

"We can see from the initial response, customer demand is off the charts," an Apple spokeswoman told Reuters.

The company's website showed delivery times pushed out to five to six weeks for the phone, compared to an initial plan of Nov. 3.

IPhone X's launch follows weeks of concerns among analysts about Apple's strategy of launching two phones within months of each other, in contrast to its approach in the past.