NEW YORK - Shares of Apple Inc. plunged to a 52-week low Monday and flirted with the $100 line after analysts downgraded the stock because they believe slowing consumer spending will hit its computer business.

The downgrades compounded losses in the general market due to the continuing credit drama. The stock fell $22.98, or 17.9 percent, to close at $105.26. Earlier in the day, the shares touched $100.59, the lowest level since early 2007.

Morgan Stanley analyst Kathryn Huberty downgraded Apple to "Equal-weight" from "Overweight," saying she was concerned that growth in the Macintosh unit is slowing down. The PC market is feeling the weakness in consumer spending, and Morgan Stanley's analysis indicates that growth will shift to the low end of the market, where Apple doesn't really play, Huberty said.

Huberty also said that even in the best of cases, Apple's earnings growth will slow down from the quarter that ended in June. She cut her earnings estimate for fiscal 2009, which just started, to $5.47 from $5.91 per share.

RBC Capital Markets analyst Mike Abramsky reduced his rating on the stock to "Sector Perform" from "Outperform" for similar reasons. He noted that the bank's surveys of consumers indicated a big drop in the number intending to buy a Macintosh computer, and trimmed his estimate for fourth-quarter Mac sales to 2.9 million from 3 million.

Abramsky raised his iPhone sales estimate to 6 million units from 5 million, but he still trimmed his fiscal 2008 earnings estimate by 2 cents to $5.26 per share. He put fiscal 2009 earnings at $5.47 per share, down from $6.07.

Apple has already forecast a drop in margins for just-ended quarter and 2009 because of back-to-school promotions and the launch of new products.

Apple's stock had a banner year in 2007, more than doubling in value. It set a 52-week high of $202.96 at the end of the year. With Monday's decline, the stock has given back most of the 2007 gains.

Shares of competitor Dell Inc. fell $1.59, or 9.4 percent, to $15.41. Hewlett-Packard Co. fell $3.26, or 6.8 percent, to $44.55.