Stocks fell on Friday on worry about earnings quality after General Electric Co missed quarterly estimates, discouraging investors after Wall Street's four-day rally.

GE's profit fell by almost half as the slump that has gripped its finance and media businesses took hold of its heavy industrial units. The conglomerate's revenue fell 17 percent and its stock slid 6.2 percent to $11.63.

With companies such as Intel Corp and Goldman Sachs Group posting strong quarterly results earlier in the week, investors had been eager to see some consistency from other bellwether names.

GE numbers are not a good sign and a reflection of the global economy still being weak, said Bill Strazullo, chief market strategist at Bell Curve Trading in Boston. The market is holding in, but it is not all clear.

Despite Friday's decline, the broad S&P 500 index is on track to post its largest weekly percentage advance since mid- March.

Shares of Google fell 3.1 percent to $429.07 on Nasdaq after news that the weak economy and a slump in advertising spending took a toll on revenue growth at the Internet giant. Its results, posted late on Thursday, beat Wall Street's expectations, however.

Bank of America posted lower earnings and Citibank relied on a gain off its Smith Barney deal with Morgan Stanley to turn a profit. [ID:nSP533186] Shares of Bank of America dropped 2.7 percent to $12.82, while Citigroup's stock was up 0.7 percent at $3.05.

The Dow Jones industrial average <.DJI> dropped 9.22 points, or 0.11 percent, to 8,702.60. The Standard & Poor's 500 Index <.SPX> fell 4.76 points, or 0.51 percent, to 935.98 while the Nasdaq Composite Index <.IXIC> slid 8.44 points, or 0.44 percent, to 1,876.59.

Even with Friday's modest pullback, all three major U.S. stock indexes are on track for their best week since mid-March. Both the Dow and the S&P 500 are set to snap four-week losing streaks.

The S&P 500 had climbed as much as 40 percent from its 12-year closing low hit in early March, but the run-up stalled in June. The benchmark index had dropped 7 percent from the rally's June peak. But after an upbeat start to second-quarter earnings season, it is up 38.5 percent from the March low.

In other earnings news, a spike in shares of International Business Machines Corp helped cushion the Dow industrials, after the company raised its full-year earnings forecast late on Thursday.

On the economic front, data showed U.S. housing starts and building permits jumped more than expected in June, propelled by a surge in single-family home starts.

Shares of DR Horton , up 2.4 percent at $9.87, helped push the Dow Jones U.S. home construction index <.DJUSHB> up 1.7 percent.

(Editing by Jan Paschal)