US STOCKS-Apple falls in heavy volume, but may find support

* Indexes off: Dow 1.3 pct, S&P 1.3 pct, Nasdaq 1.6 pct

By Ryan Vlastelica

NEW YORK, Sept 25 (Reuters) - Apple Inc (NasdaqGS: AAPL - news) shares were tumbling on Thursday, with the tech company suffering one of its biggest daily declines of the year and breaking under key technical levels.

The stock was pressured after Apple pulled back an update to its new operation system, which some users complained had resulted in a drop in cellular service and an inability to use the fingerprint-reading Touch ID feature.

The issues, which Apple said it would fix in another software update to be released in the next few days, were the latest snag for the rollout of the company's iPhone 6 and 6 Plus lines. While the launch was hugely successful, with Apple shipping 10 million units in the first weekend, the large-screen device was also hit by claims that it could bend when placed in back pockets.

Shares (Berlin: DI6.BE - news) lost 3 percent to $98.66, moving on volume of about 60 million shares, already ahead of their 50-day average of 56.46 million. The stock earlier fell as much as 4 percent, at one point breaking sharply below its 50-day moving average of $98.74.

Currently, Apple is holding at that level, suggesting it may serve as support against deeper losses. The stock hasn't closed below its 50-day moving average since April 23, though it remains well under its 14-day moving average.

Apple is the biggest drag to both the Nasdaq and the S&P 500, where it is accounting for almost 3 points of the benchmark index's 26-point decline.

Index snapshot at 12:07 EDT:

* S&P 500 was falling 25.01 points, or 1.25 percent.

* Nasdaq Comp was losing 73.50 points, or 1.61 percent.

* Dow industrials was dropping 214.71 points, or 1.25 percent.

* Russell 2000 was falling 15.46 points, or 1.37 percent.

* S&P MidCap was dropping 17.2 points, or 1.23 percent.

* S&P SmallCap was losing 8.42 points, or 1.3 percent.

(Editing by Meredith Mazzilli)