Apple Senior Vice President of Worldwide Marketing, Phil Schiller, shows the AirPower wireless charging mat during a launch event in Cupertino, California, US, Sept 12, 2017. [Photo/Agencies]

Apple normally ships new products within a week or two of announcing them, though Cook said the later date was consistent with earlier guidance to investors.

"It's great to have a product but we'd have liked it sooner rather than later, more like the beginning of October or mid- October," said Kim Forrest, senior equity research analyst at Fort Pitt Capital Group in Pittsburgh.

Apple shares closed down 0.4 percent. They had traded as much as 1 percent higher during the launch event before reversing course.

Tim Ghriskey, chief investment officer of Solaris Asset Management in New York, said he was not worried about the ship date and liked the new phones features, but also flagged a lack of surprises.