* Apple extends streak of strong numbers from big names
* GE, McDonald's fall after results, hitting Dow
* Philly Fed, jobless claims tamper enthusiasm
* Dow up 0.4 pct, S&P up 0.5 pct, Nasdaq up 0.6 pct (Updates to close, changes byline)
By Ryan Vlastelica
NEW YORK, April 21 (Reuters) - U.S. stocks posted their first positive week in three as more healthy earnings news lifted Wall Street on Thursday, though gains were limited with another 180 S&P names due to report next week.
Apple's blowout results and strong reports from a number of industrials kept sentiment on the bullish side, after investors were on guard for disappointments headed into this week.
Another increase in jobless claims and underwhelming results from General Electric and McDonald's kept gains in check. The S&P 500 ran into resistance close to 1,340, a level that has triggered selling plenty of times this month. Some see a failure to convincingly rise above 1,344, the recent high in the benchmark, as a bearish technical signal.
Volume was light, with about 6.45 billion shares traded on the New York Stock Exchange, the American Stock Exchange and Nasdaq, below last year's daily average of 8.47 billion.
"Objectively, the earnings season is still mixed, but since the most recent results were strong, it increases the perception that we'll have a good first half of the year," said Tommy Huie, who oversees about $34 billion as president and chief investment officer of M&I Investment Management in Milwaukee.
Apple Inc rose 2.4 percent to $350.70 a day after posting results that surged past expectations, joining F5 Networks, DuPont and other names that increased the perception of a healthy corporate America after some names' early results disappointed.
Along with GE and McDonald's, the Dow's advance was limited by Verizon Communications Inc. GE shares fell 2.2 percent to $19.95 while Verizon lost 2.3 percent to $36.91 and McDonald's was off 1.9 percent at $76.91.
Factory activity in the U.S. Mid-Atlantic region slowed sharply in April and the number of claims for unemployment insurance fell less than expected last week, implying the economy was struggling to regain momentum.
"That claims didn't decline as much and (factory activity) cooled down suggests that we could be more likely for a pullback," said Donald Selkin, chief market strategist at National Securities in New York. "I don't see how we can maintain these gains."
The Dow Jones industrial average was up 52.45 points, or 0.42 percent, to end at 12,505.99. The Standard & Poor's 500 Index was up 7.02 points, or 0.53 percent, at 1,337.38. The Nasdaq Composite Index was up 17.65 points, or 0.63 percent, at 2,820.16.
The Dow climbed as high as 12,506.06, its highest intraday level since early June 2008.
For the week, both the blue-chip index and the S&P 500 are up 1.3 percent while the Nasdaq, lifted by strong tech results, rose 2 percent.
Other notable companies, including Travelers Cos Inc, Morgan Stanley and UnitedHealth, advanced following quarterly results.
Travelers gained 3.7 percent to $61.32 and was the Dow's top gainer while Morgan Stanley rose 1.7 percent to $26.48, DuPont added 1 percent to $55.91 and UnitedHealth rose 8.1 percent to $47.81.
Biogen Idec was the S&P 500's top gainer, up 15.2 percent at $99.70, after it released promising data from a clinical trial of an experimental multiple sclerosis drug.
About two stocks rose for every one that fell on the New York Stock Exchange, while on the Nasdaq, about three stocks rose for every two that fell. (Reporting by Ryan Vlastelica; Editing by Jan Paschal)