* U.S. Treasuries little changed, some T-bill yields negative * U.S. dollar above 100 yen, euro weakens * WTI crude at nine-month high above $99 By Rodrigo Campos NEW YORK, July 2 (Reuters) - The U.S. dollar hit its highest in a month against the yen and euro on Tuesday while a gauge of global equities fell as U.S stocks reversed course to end slightly lower. Wall Street slipped in a volatile session, weighed mostly by declines in shares in the industrial sector as the S&P 500 once again lost steam after it bumped against its 50-day moving average. "We saw the market moving to the downside right around that 50-day moving average. It's a bit technical here but on a day like today, it's an area that people are looking (at) closely and so far, it's been serving as a bit of resistance," said Ryan Detrick, senior technical strategist at Schaeffer's Investment Research. The S&P has not been able to close above its 50-day average since ending below it on June 20. Trading will likely continue to be thin all week, with U.S. markets closing early on Wednesday and all of Thursday for the U.S. Independence Day holiday. The lower volume could translate into increased volatility, especially with the release of the U.S. nonfarm payroll report on Friday. The Dow Jones industrial average fell 42.55 points or 0.28 percent, to end at 14,932.41, the S&P 500 lost 0.88 point or 0.05 percent, to close at 1,614.08 and the Nasdaq Composite dropped 1.09 points or 0.03 percent, to 3,433.4. The S&P's session high was 1,624.26, marginally above its 50-day average of 1,623.94. The MSCI gauge of major global stock markets fell 0.2 percent. GREENBACK GAINS The dollar hit a one-month high against the yen at 100.72 yen and rose to a near five-week peak against a basket of currencies on expectations Friday's U.S. jobs data will bolster the chances that the Fed will scale back its stimulus measures sooner than expected. Comments from Fed officials have recently turned markets on their heads as traders try to guess how soon the central bank will start to wind down its $85 billion monthly bond purchases. This program, known as quantitative easing, has been instrumental for the rally in stocks and has helped keep interest rates near historic lows, while putting downward pressure on the greenback. "There's still a bias overall for a stronger dollar because of tapering expectations," said Brian Kim, currency strategist at RBS Securities in Stamford, Connecticut. "Although some Federal Reserve officials have tried to temper these expectations, the market view is that tapering will come sooner rather than later." The head of the New York Fed reiterated in a speech on Tuesday that the U.S. central bank will likely continue to support the economic recovery for some time despite market worries that it would pull back soon. The yen's weakness helped Japan's Nikkei stock index close 1.8 percent higher, above 14,000 for the first time in five weeks, as shares of blue-chip exporters rose. U.S. dollar-denominated Nikkei futures were up 1.9 percent, extending the gains in the past four sessions to 8.9 percent. The euro fell 0.7 percent to $1.2975 and hit a low of $1.2962, its lowest since early June. Prices of U.S. Treasuries traded little changed as investors paused before the U.S. holiday and labor market data. "The market's in a bit of a holding pattern as we await Friday's employment report," said Ian Lyngen, senior government bond strategist at CRT Capital Group in Stamford, Connecticut. The benchmark 10-year Treasury note was up 2/32 in price to yield 2.4711 percent. Interest rates on some Treasury bills turned negative as investors scrambled for cash-like assets to guard against volatile trading that could come from Friday's jobs data. With Greece due to repay 2.2 billion euros of bonds in August, yields on 10-year Greek bonds were up 14 basis points at 11.18 percent. Portugal's bond yields widened 22 basis points to 6.62 percent after the finance and foreign ministers quit on consecutive days. In commodities trading, Brent crude rose near $104 a barrel , extending gains to a second day due to concerns about supply disruptions in the Middle East and Africa while U.S. crude was up 1.6 percent to $99.45 after hitting its highest since September. Copper fell from a near two-week high in the previous session as a stronger dollar weighed on the price and investors remained concerned about economic prospects in top metals consumer China. Three-month copper traded down 0.7 percent to $6,907 a tonne, partly reversing the previous session's 3.4 percent rally.