By Caroline Valetkevitch

(Reuters) - U.S. stocks dropped for a second straight day on Friday following another drop in oil prices and renewed worries about the global economy.

Ahead of Britain's June 23 referendum on whether to stay in the European Union, a poll showed those in favor of Britain exiting the EU, or "Brexit," were well ahead of those who favor remaining. The British pound fell against the dollar.

"The global economy is weak and it can't handle any major shocks. If Brexit occurs, that's a major shock," said Adam Sarhan, chief executive of Sarhan Capital in New York.

The S&P 500 pulled further away from a record high after coming within about 12 points on Wednesday. The benchmark, which also ended lower for the week, is now 1.6 percent shy of its 2,130.82 record close, reached in May 2015.

"Because we failed to break through to new highs, everybody's attention shifts back to reality, and they start looking for reasons to sell and take some profits," said Robert Pavlik, chief market strategist at Boston Private Wealth in New York.

Investors are bracing for next week's Federal Reserve meeting, though the U.S. central bank is expected to leave rates unchanged.

Leading losses for the day, the S&P energy index <.SPNY> was down 2 percent. U.S. crude fell 3 percent to end back below $50 a barrel.

The Dow Jones industrial average <.DJI> closed down 119.85 points, or 0.67 percent, to 17,865.34, the S&P 500 <.SPX> lost 19.41 points, or 0.92 percent, to 2,096.07 and the Nasdaq Composite <.IXIC> dropped 64.07 points, or 1.29 percent, to 4,894.55.

For the week, the S&P 500 was down 0.1 percent and the Nasdaq lost 1 percent, but the Dow was up 0.3 percent.

Investors around the world swapped equities for less risky assets such as U.S. Treasury bonds and the Japanese yen. Yields on government bonds fell globally, while the S&P financial index <.SPSY> was down 1.2 percent.

Jeffrey Gundlach, chief executive of DoubleLine Capital, said Friday investors are dropping risky assets because of falling GDP expectations amid China's slowing growth and the intensifying U.S. presidential race.

Some stock investors are betting on a return of the volatility that marked the first two months of the year. The bounce-back in commodity prices that fueled much of the 13.3-percent rally in S&P 500 index from its February lows is leveling off.

The CME Volatility index <.VIX>, Wall Street's fear gauge, jumped 16.3 percent.

Among Wall Street's few bright spots on Friday was Intel <INTC.O>, up 0.3 percent. Bloomberg reported the chipmaker would replace Qualcomm as an Apple <AAPL.O> supplier for some iPhones. Qualcomm <QCOM.O> was down 2.1 percent.

About 6.8 billion shares changed hands on U.S. exchanges, in line with the average for the past 20 trading days, according to Thomson Reuters data.

NYSE declining issues outnumbered advancers by a 4.24-to-1 ratio; on the Nasdaq, a 3.75-to-1 ratio favored decliners.

The S&P 500 posted 33 new 52-week highs and no new lows; the Nasdaq recorded 30 new highs and 39 new lows.

(Additional reporting by Yashaswini Swamynathan in Bengaluru; Editing by Savio D'Souza and Nick Zieminski)