Leading US shares have fallen on Wall Street, dragged lower by Apple, which slipped 3.5% after the technology giant was forced to pull an update to its iOS 8 operating system.
The main Dow Jones index was down more than 200 points, or 1.3%, at 16,986 in early trading.
Investor confidence was also knocked by weak durable goods orders figures released by the Commerce Department.
European markets also fell sharply after Wall Street opened.
Germany’s Dax and France’s Cac 40 indexes were down about 1.5%, while the UK’s FTSE 100 was 1.2% lower.
Other technology stocks listed on Wall Street were also hit by Apple’s slide – both Microsoft and Intel were down 1.6%.
Earlier, the world’s biggest technology company apologised after an update to iOS 8.0.1 left some iPhone users unable to make or receive calls.
The company is also under fire following claims that its new iPhone 6 Plus had bent while in users’ pockets.