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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 0.4 pct, S&P 0.4 pct, Nasdaq 0.7 pct (Updates to open, adds housing data)
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 7.1 percent to $373.13 a dayafter results showed strong subscriber growth, a sign thetrading favorite still had room to grow despite recent concernsover its valuation.
Also helping lift the Internet space was Facebook Inc, which rose 2.3 percent to $62.64 after Credit Suisseupgraded the social networking company to "outperform."
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 0.7percent to $87.04 while United Tech was up 1 percent at $119.49.
On the downside, McDonald's Corp reported earningsthat fell alongside a drop in U.S. same-store sales. Shares ofthe Dow component fell 0.2 percent to $99.45.
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, now 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 57.83 points,or 0.35 percent, at 16,507.08. The Standard & Poor's 500 Index was up 7.23 points, or 0.39 percent, at 1,879.12. TheNasdaq Composite Index was up 29.53 points, or 0.72percent, at 4,151.08.
Both the S&P and Nasdaq are on track for a sixth straightday of gains. The S&P has gained 3.5 percent over that periodwhile the Nasdaq is up 3.8 percent.
In company news, Allergan Inc jumped 17.5 percent to$166.75 a day after activist investor William Ackman teamed upwith Canadian drugmaker Valeant Pharmaceuticals InternationalInc to bid for the company.
General Motors Co filed a motion in a U.S. bankruptcycourt to enforce a bar on lawsuits related to ignition defectsin cars sold before its 2009 bankruptcy as it fights a classaction lawsuit that seeks to set aside the restriction. Sharesof the automaker rose 0.7 percent to $34.21.
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)
