Updated

Apple shares are plunging after the company reported quarterly results that point to growth slowing after five blowout years.

The stock was down $50.68, or 9.9 percent, at $463.32 in late morning trading.

Even with the stock's decline, Apple Inc. is the world's most valuable company, a position it's held for more than a year. But it's now worth just 4 percent more than No. 2 Exxon Mobil Corp.

Late Wednesday, Apple reported October-December earnings that were flat compared with the year before. It predicted sales growth for the current quarter of around 7 percent — far from the 50-percent-plus rate it's often hit in recent years. Analysts believe Apple is unable to fully capitalize on the global smartphone boom with just one new — and very expensive — phone model every year.