* Apple's leap of 5.1 pct helps Nasdaq squeak out a gain
* Caterpillar, AT&T hit Dow, Boeing falls after lifetime high
* Facebook, Baidu fly in after-hours trading on results
* Visa and Qualcomm climb late following earnings
* Dow down 0.2 pct, S&P 500 off 0.4 pct, Nasdaq up 0.01 pct
By Alison Griswold
NEW YORK, July 24 (Reuters) - U.S. stocks mostly retreated on Wednesday as falling utility and commodity shares more than offset gains in the tech sector on Apple's solid earnings.
The Dow Jones industrial average ended slightly lower a day after closing at a record high. Caterpillar and AT&T dragged on the Dow following weak results. Earnings, as a whole, were mixed, with better-than-expected news from Boeing Co But blue-chip Boeing's stock also ended the day lower.
The benchmark S&P 500 logged its first back-to-back declines in a month. On Tuesday, the S&P 500 closed slightly lower after setting a record intraday high of 1,698.78.
The tech-driven Nasdaq barely finished in positive territory, eking out a gain of less than a point despite a 5.1 percent jump in shares of Apple.
Peter Jankovskis, co-chief investment officer of OakBrook Investments LLC in Lisle, Illinois, said investors are in a "wait-and-watch" phase as earnings come out.
"They gave us a lift during the first half of the month, and they're now having a difficult time sustaining that momentum," he said. "I think the pop that we're going to get out of earnings has already occurred."
The Dow Jones industrial average slipped 25.50 points, or 0.16 percent, to end at 15,542.24 - a day after closing at a record 15,567.74. The Standard & Poor's 500 Index fell 6.45 points, or 0.38 percent, to finish at 1,685.94.
But the Nasdaq Composite Index inched up 0.33 of a point, or 0.01 percent, to close at 3,579.60.
Shares of Facebook Inc surged 20.1 percent in extended-hours trading after the company said its revenue in the second quarter increased 53 percent, surpassing Wall Street's targets. During regular trading, Facebook's stock rose 1.5 percent to end at $26.51, ahead of its results.
Baidu Inc shares shot up 12.2 percent in extended-hours trading after China's largest search engine posted slightly better-than-expected revenue of $1.23 billion in the second quarter. Baidu's stock ended regular trading at $113.37, up 3.2 percent ahead of its earnings.
In other trading after the bell, Visa Inc shares added 2.1 percent after the company reported a quarterly profit that beat Wall Street's estimates, as customers spent more using its cards. Visa also raised its outlook for full-year revenue and earnings. Visa's stock ended regular trading at $186.75, down 1 percent.
Shares of Ameriprise Financial Inc were unchanged in extended-hours trading after the company reported a stronger-than-expected rise in second-quarter profit. The company credited its wealth management business with driving its results. The stock ended the regular session at $86.24, down 0.5 percent.
Qualcomm Inc shares rose 4.5 percent in extended-hours trading after the leading mobile chipmaker posted third-quarter results that met expectations and eased concerns about slower growth of smartphone sales. During Wednesday's session, Qualcomm fell 1.5 percent to $61.39, ahead of its results.
Stocks fell across the board during Wednesday's regular trading. Nine of the 10 S&P 500 industry sector indexes slid. The utilities index was the worst performer, shedding 1.6 percent, while the materials and energy indexes fell nearly 1 percent apiece.
Analysts said the stock market was pausing as investors booked profits after a sizable upward move over the past month. The S&P 500 has added as much as 7.8 percent since late June, and it has set some record closing highs along the way.
Tech bellwether Apple rose 5.1 percent to $440.51 a day after it reported earnings and revenues that beat Wall Street's estimates, helping to keep the Nasdaq afloat and bolster the S&P 500's tech shares as well. The S&P tech sector index rose 0.86 percent to end at 506.92, after climbing as much as 1.4 percent earlier in the day.
Caterpillar and AT&T, on the other hand, disappointed investors after posting results. Caterpillar shares fell 2.4 percent to $83.44. AT&T shares tumbled 1.2 percent to $35.40.
Boeing, also a Dow component, posted upbeat second-quarter results, but the stock fell 0.8 percent to close at $106.95 after hitting a lifetime intraday high of $109.48.
Shares of Nasdaq OMX Group fell 3 percent to $32.81 after the transatlantic exchange operator company reported a 5.4 percent drop in quarterly profit.
T. Rowe Price Group shares slid 5 percent to end at $75.61 after the asset management company reported second-quarter results that missed Wall Street's expectations.
Broadcom shares sank 15.1 percent to $27.01 a day after the chipmaker forecast lower-than-expected third-quarter revenue. At least four brokerages cut their ratings and about 10 lowered their price targets on Broadcom's stock.
Of the 169 companies in the S&P 500 that have reported results so far this season, 65.7 percent have beaten analysts' expectations for earnings and 53.3 percent have posted revenue above forecasts. Over the past four quarters, 67 percent of companies have beaten earnings estimates.
Shares of little-known uranium company USEC Inc gained for a ninth consecutive day, extending a meteoric rise. On Wednesday, the stock soared 7.1 percent to end at $13.35.
About 6.2 billion shares changed hands on U.S. exchanges, slightly below the daily average of about 6.4 billion.
Decliners outnumbered advancers on the New York Stock Exchange by a ratio of 3 to 1. On the Nasdaq, three stocks fell for every two that rose.