US STOCKS-Earnings lift S&P 500, Nasdaq; S&P's best week since July
* S&P 500 scores biggest weekly percentage gain since July
* Morgan Stanley, GE shares rally after results
* Google, IBM shares fall a day after posting earnings
* Dow off 0.1 pct; S&P 500 up 0.1 pct; Nasdaq up 0.2 pct (Updates to close)
By Ryan Vlastelica
NEW YORK, April 17 (Reuters) - U.S. stocks ended a holiday-shortened week with mostly modest gains on Thursday, though the S&P 500 notched its biggest weekly advance since July as Morgan Stanley and General Electric rallied after strong results.
The two were the latest to post earnings that topped expectations, helping to lift the S&P 500 and the Nasdaq to their fourth straight daily advance. Tech bellwethers Google and IBM fell on disappointing figures and limited the broader market's gain. IBM's slide pushed the Dow into slightly negative territory at the close.
With less than one-fifth of S&P 500 companies having reported results so far, about 63 percent have topped earnings expectations, according to Thomson Reuters data, exceeding the 56 percent average over the past four quarters. About 52 percent have beaten revenue forecasts, about even with the 54 percent average over the past four quarters.
Morgan Stanley rose 2.9 percent to $30.76 after the financial services company reported a rise in first-quarter earnings, while Goldman Sachs edged up 0.1 percent to $157.44 after reporting earnings that fell less than expected. Continuación...