NEW YORK (AP) — Shares of Apple Inc. fell further Tuesday, hitting an 11-month low, as fears increased that iPhone 5 sales at the end of last year were below expectations.

THE SPARK: Apple shares have been dropping steadily since September. But their decline this week was set off by reports in the Japanese newspaper Nikkei and The Wall Street Journal. They said Apple has slashed its orders for iPhone 5 parts because the device isn't selling as well as the company hoped. Both publications cited unidentified people familiar with the situation.

THE BIG PICTURE: Apple shares peaked at $705.07 on Sept. 21, the day the Cupertino, Calif., company's iPhone 5 was released.

The phone has become Apple's most valuable product, but is facing stiff competition from other devices running Google Inc.'s Android software.

THE ANALYSIS: Stuart Jeffrey at Nomura Securities on Tuesday cut his earnings estimates for Apple's current fiscal year, which ends in September, and the next one.

He thinks that in the next few years, Apple may have to lower the price for the iPhone, which could hurt the company's profitability. That puts the current value of the shares between $495 and $579, he calculated.

Apple is set to report October-December results on Tuesday. It's the first full quarter the iPhone 5 has been on sale.

SHARE ACTION: Apple shares fell $16.19, or 3.2 percent, to $485.56 in afternoon trading. The shares on Monday dipped below $500 for the first time since February, but closed at $501.75.