SIGNS of poor demand for the iPhone 8 fuelled more market questions over Apple Inc's double 2017 iPhone release strategy, sending its shares down as much as 2.6 percent on Thursday.

The chief executive of Canada's largest mobile network Rogers Communication said appetite for the latest iPhone had been "anemic", adding to a series of hints that sales of the first of two new phones Apple releases this year is poor.

A number of sector analysts played down the concerns, which have dogged Apple since it announced the plans on Sept. 12, saying that overall phone production looks broadly in line with their earlier expectations.

But the debate - and hints from some analysts and a Taiwan media report of a cut in iPhone 8 production - was enough to push Apple shares down 2.3 percent at the open in New York.

"The Street is hyper-sensitive to any speed bumps around this next iPhone cycle and (that) speaks to the knee-jerk reaction we are seeing in shares this morning," said Daniel Ives, chief strategy officer with investment research house GBH Insights in New York.

He said his own checks showed that only 20-25 percent of iPhones sold over the next 12-18 months would be iPhone 8s or 8 Plus, an argument that meant investors should look past cool demand in the first month of its launch.

"iPhone 8 demand has been naturally soft out of the gates with the main event being the iPhone X launch in early November," he said.

"This is the early innings of what we believe is the biggest iPhone product cycle with X leading the way."

Apple no longer gives regular updates on sales numbers but indications from supply channels, phone operators and analysts who track the sector have fueled talk of poor sales for the latest update of the smartphone.

When Apple announced the plan to release both phones before the end of 2017, fans were disappointed mainly due to the delay in the launch of the iPhone X until November.

But there are also concerns that the more expensive phone may not get so many takers.

Rogers Communications CEO Joe Natale said anticipation was high for the iPhone X but also noted that inventory would be limited and that - at Apple's starting price of $999 - it was an expensive device.

U.S. wireless carrier AT&T also said last week its third-quarter postpaid handset upgrades were fewer by nearly 900,000 from a year ago.

KeyBanc Capital Markets analyst John Vinh reported earlier this week that a carrier store survey suggested the iPhone 7 was outselling its successor just a month after the latter's launch.

That suggests buyers are more price sensitive and goes against the history of iPhone releases, which traditionally sees fans queueing for the new device.

The iPhone X will go on sale from Nov. 3.

Deutsche Bank analysts were among those playing down the importance of any cut in iPhone 8 production in favor of iPhone X.

"We think the market could have over-focused on the production swing in different SKUs, but overlooked that the overall iPhone production is largely on track," they wrote in a client note.