* Outlooks from Aetna, others weigh after market run-up
* Boeing off after downgrade
* Dow off 0.5 pct; S&P 500 off 0.6 pct; Nasdaq off 0.9 pct (Updates to mid-morning)
By Ellis Mnyandu
NEW YORK, July 27 (Reuters) - U.S. stocks dipped on Monday as profit-taking and worrying outlooks from companies such as Aetna Inc overshadowed data that hinted the housing market was stabilizing.
Profit-taking weighed on such hard-charging stocks as Apple Inc as investors looked for fresh catalysts to justify further equity gains following the market's surge of more than 40 percent from 12-year lows in early March. Apple dropped 1.2 percent to $158.19.
A report that sales of new single-family homes in the United States rose more than expected in June, while the inventory of homes for sale fell to a more than 11-year low, gave the market a brief early boost.
"The market is very short-term extended, and it could use some time out to recharge the batteries. But we've got a lot of momentum behind the market," said Scott Marcouiller, senior equity market strategist at Wells Fargo Advisors in St. Louis.
"The question is have we discounted what we've been rallying on, or have we fully discounted the less bad than expected?" Marcouiller said.
The Dow Jones industrial average fell 46.78 points, or 0.51 percent, to 9,046.46. The Standard & Poor's 500 Index dropped 5.94 points, or 0.61 percent, to 973.32. The Nasdaq Composite Index slipped 17.18 points, or 0.87 percent, to 1,948.78.
Aetna, the No. 3 U.S. health insurer, cut its full-year earnings outlook due to higher-than-projected medical costs and posted a 28 percent drop in second-quarter net income. The stock slid 5.1 percent to $25.08.
Verizon Communications Inc, the biggest U.S. mobile service, posted an in-line second-quarter operating profit, but said it will cut 8,000 jobs in its landline business in a move that underscored continuing fallout from the economic slump.
Verizon shares dropped 2.7 percent to $30.66, making the stock the Dow's second worst drag behind Boeing Co, which fell 2 percent to $41.54 after a broker downgrade.
On the bright side, the Dow Jones home construction index climbed 2.7 percent as shares of home builders advanced.
Hints of stabilization in housing are seen as a positive development since fallout from the housing downturn is what pushed the economy into recession in December 2007.