Apple shares fell below $US400 for the first time in a year and half overnight, after a supplier hinted at a slowdown in iPhone and iPad production.
The stock was down $21.89, or 5.1 per cent, at $404.35 in early afternoon trading. Earlier in the day, it hit $398.11, the lowest level since Dec. 2011.
The decline means Apple has for now lost its position as the world's most valuable publicly traded company to Exxon Mobil, which has a market capitalisation a few billion dollars above Apple's $380 billion price tag.
Late on Tuesday, Cirrus Logic, which supplies audio chips for the iPhone and iPad, said sales of a particular chip are slowing down as an unnamed customer moves to a newer component.
Analyst Peter Misek at Jefferies & Co. said Cirrus' news suggests a big decline in Apple sales in the April to June period. That supports his view that Apple is unlikely to launch a new iPad Mini in the quarter, and that the next version of the full-size iPad may launch late in the quarter rather than early. In the last three years, Apple has launched a new iPad in March or April.
