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* S&P 500, Nasdaq on track for six-day advance
* Netflix up after results, Facebook gains on update
* Allergan soars as Ackman and Valeant bid for company
* Indexes up: Dow 0.6 pct, S&P 0.5 pct, Nasdaq 0.9 pct (Updates to midday trading)
By Ryan Vlastelica
NEW YORK, April 22 (Reuters) - U.S. stocks rose on Tuesday,with both the S&P 500 and Nasdaq on track for a sixth straightday of gains as a number of bellwether companies reported strongresults.
Netflix Inc surged 6 percent to $369.33 a day afterresults showed strong subscriber growth, a sign the tradingfavorite still had room to grow despite recent concerns over itsvaluation. With the day's gain, the stock returned to slightlypositive territory for the year after a 21-percent decline inMarch.
Also helping lift the Internet space was Facebook Inc, which rose 2.5 percent to $62.80 after Credit Suisseupgraded the social networking company to "outperform" on higherexpectations for the company's long-term average revenue peruser.
Dow components Travelers Cos Inc and UnitedTechnologies Corp both reported first-quarter earningsthat beat expectations, and United Tech raised the low end ofits full-year profit outlook. Shares of Travelers rose 0.2percent to $86.58 while United Tech was up 1.2 percent at$119.69.
McDonald's Corp reported earnings that fellalongside a drop in U.S. same-store sales, but shares of the Dowcomponent rose 0.2 percent to $99.88.
Better-than-expected earnings have lifted equities recently,though companies have largely been exceeding reduced forecasts.Profits are seen rising 1.1 percent this quarter, down from the6.5 percent growth rate estimated at the start of the year.
"The season has been better than many have feared, which ishelping investors feel comfortable with the pace of economicgrowth, not just in the first quarter but going forward," saidJoseph Tanious, global market strategist at J.P. Morgan AssetManagement in New York.
With 20 percent of the S&P having reported, 63 percent havetopped earnings expectations, according to Thomson Reuters data,even with the long-term average. On revenue, 51 percent haveexceeded forecasts, below the 61 percent long-term average.
The Dow Jones industrial average was up 92.93 points,or 0.56 percent, at 16,542.18. The Standard & Poor's 500 Index was up 9.50 points, or 0.51 percent, at 1,881.39. TheNasdaq Composite Index was up 38.44 points, or 0.93percent, at 4,159.99.
Both the S&P and Nasdaq are on track for a sixth straightday of gains. The S&P has gained 3.6 percent over that periodwhile the Nasdaq is up 4 percent.
In company news, Allergan Inc jumped 15 percent to$163.58 a day after activist investor William Ackman teamed upwith Canadian drugmaker Valeant Pharmaceuticals InternationalInc to bid for the company.
In the latest economic data, existing home sales fell totheir lowest level in more than 1-1/2 years in March, though thedecline was narrower than expected. (Editing by Nick Zieminski)
