* Stocks pare gains on speculation Fed tapering could start in March * Euro falls after report of possible ECB deposit rate change * Gold prices fall on Fed, Brent rises By Ryan Vlastelica and Herbert Lash NEW YORK, Nov 20 (Reuters) - U.S. stocks retreated and gold prices fell on Wednesday while U.S. Treasury yields shot higher after minutes from a Federal Reserve policy meeting in October suggested the U.S. central bank could begin to scale back its bond buying in March. Most stocks on Wall Street pared gains to turn lower, with the Nasdaq hovering above break-even. Spot gold prices fell 2.4 percent to $1,242.50 an ounce. Officials felt they could decide to start scaling back the Fed's massive $85-billion-a-month asset-purchase program at one of the bank's next meetings, provided this was warranted by economic growth, the Fed minutes showed. Policymakers are next scheduled to gather on Dec. 17-18. "We take these minutes as meaning March is the most likely scenario for tapering. There's no overwhelming case to be made for them to act in December," said Michael Woolfolk, senior currency strategist at BNY Mellon in New York. Woolfolk said he was surprised by the relatively little attention given to the impact of the 16-day government shutdown in October. "Maybe it really was a non-event, judging by today's retail sales data and the October nonfarm payrolls," he said. Comments from a senior Fed official that a solid U.S. jobs report for November would increase the likelihood of a reduction in bond purchases beginning as early as December gave a further boost to bond yields. The Dow Jones industrial average fell 54.88 points, or 0.34 percent, to 15,912.15, the S&P 500 lost 5.1 points, or 0.29 percent, to 1,782.77 and the Nasdaq Composite dropped 5.999 points, or 0.15 percent, to 3,925.555. The euro fell sharply on a report saying the European Central Bank was considering a negative deposit rate. Bloomberg reported that if the ECB were to take the deposit rate for cash it holds overnight for banks into negative territory, it would consider -0.1 percent. The current rate is zero. An ECB spokesperson declined to comment. The euro fell to a low of $1.3430, and last traded down 0.74 percent at $1.3426. The U.S. dollar index rose 0.49 percent to 81.099. The Fed's program and similar programs from other major central banks have fueled equity gains in 2013, taking Wall Street to repeated all-time highs and other regions around the world to multi-year highs. The FTSEurofirst 300 ended up 0.12 percent at 1,297.38. While the Fed's accommodative monetary policy is expected to provide a floor under equities for as long as it continues, questions about when it will start to be slowed have tempered buying enthusiasm. In addition, the size of the rally has market participants seeking new catalysts in an environment marked by signs of tepid economic growth. The MSCI world share index fell 0.5 percent. U.S. equities earlier were boosted by data showing consumer spending rose more than expected in October, while consumer prices unexpectedly fell. Among other asset classes, Brent crude oil futures rose $1.14 to settle at $108.06 a barrel. U.S. crude fell 1 cent to settle at $93.33. The benchmark 10-year U.S. Treasury note fell 19/32 in price to yield 2.7806 percent.