Wall Street slips on Spain, earnings worries

Traders work on the floor of the New York Stock Exchange October 1, 2012.

NEW YORK (Reuters) - Wall Street ended little changed in a volatile session on Tuesday as uncertainty over when Spain might apply for a bailout shackled a market struggling to build on gains that took the S&P 500 to its highest in nearly five years.

The market was also hamstrung by concerns about the upcoming reporting period that kicks into full gear next week.

The Dow was pressured by stocks closely tied to the pace of growth, including Caterpillar Inc (CAT.N) and Boeing Co (BA.N). A major headwind for the economy has been declining demand from Europe, which has been drifting toward recession.

Spanish Prime Minister Mariano Rajoy said a request for European aid was not imminent following a report the country could apply for help soon. Germany has signaled that Madrid should hold off on making its request, according to European officials on Monday.

"The market is reacting more to the (Spain) news because it wants to consolidate after a pretty good run. The market is making this news even bigger than it really is just to make it an excuse to sell," said Frank Gretz, market analyst at Wellington Shields & Co in New York.

The S&P rose nearly 6 percent in the third quarter, lifted by accommodative moves by the Federal Reserve and European Central Bank, which market participants bet would boost flagging growth.

If Madrid were to seek a rescue, it would trigger European Central Bank buying of its bonds and help to ease U.S. investors' nervousness about impact of the euro zone's debt crisis on the U.S. economy.

"Until we get some kind of clarity, we should expect a lot of volatility and difficulty holding on to gains," said Brian Barish, president of Cambiar Investors LLC in Denver.

The Dow Jones industrial average .DJI was down 32.83 points, or 0.24 percent, at 13,482.28. The Standard & Poor's 500 Index .SPX was up 1.26 points, or 0.09 percent, at 1,445.75. The Nasdaq Composite Index .IXIC was up 6.51 points, or 0.21 percent, at 3,120.04.

Weaker-than-expected results from Mosaic (MOS.N) added to worries about the upcoming third-quarter earnings period. Mosaic shares fell 3.9 percent to $55.76.

Vanguard Group, the largest U.S. mutual fund manager, said it was switching 22 of its biggest index funds away from benchmarks provided by MSCI Inc (MSCI.N) in order to cut costs.

Shares of Chipotle Mexican Grill Inc (CMG.N) took a nosedive when hedge fund manager David Einhorn said the restaurant chain will face significant competition and additional costs, making it an attractive "short." The stock fell 4.2 percent to $302.96.

In a presentation at the annual Value Investing Congress in New York, Einhorn highlighted some stocks he expects will rise such as General Motors (GM.N). GM shares rose 2.6 percent to $23.68.

Car companies reported September sales, with General Motors and Chrysler Group LLC posting gains while Ford Motor Co (F.N) remained flat.

GM, the largest U.S. automaker, reported a 1.5 percent increase, while Ford reported sales on par with its results from a year earlier. Chrysler showed a 12 percent jump in sales.

PetSmart Inc (PETM.O) shares added 1.5 percent to $68.55 after S&P Dow Jones Indices said after Monday's close the company will replace Sunoco SUN.N in the S&P 500 on October 4.

About 5.7 billion shares changed hands on the New York Stock Exchange, Amex and Nasdaq, compared with the average daily volume of 6.38 billion.

(Reporting by Angela Moon; Editing by Chizu Nomiyama)