U.S. stocks rallied on Tuesday, sending the benchmark S&P 500 to its biggest one-day percentage run-up in three months, as Merck's strong earnings and upbeat regional manufacturing data boosted optimism about the economic outlook.

* Natural resource stocks, including miners and energy companies, were standouts as the U.S. dollar retreated, sending global commodity prices higher.

* Based on the latest available data, the Dow Jones industrial average <.DJI> finished up 169.67 points, or 1.68 percent, at 10,268.81. The Standard & Poor's 500 Index <.SPX> gained 19.36 points, or 1.80 percent, to close at 1,094.87. The Nasdaq Composite Index <.IXIC> ended up 30.66 points, or 1.40 percent, at 2,214.19.

* The S&P 500 has trimmed its losses from its January 19 peak to just under 5 percent after falling as much as 8 percent early last week.

(Reporting by Ellis Mnyandu; Editing by Kenneth Barry)