U.S. stock index futures pointed to a higher open for Wall Street on Tuesday as the U.S. dollar hit a 1-year low against the euro ahead of the start of a Federal Reserve policy meeting, boosting oil and metals prices.

The Federal Reserve starts its two-day monetary policy meeting on Tuesday with a decision on interest rates due at around 2:15 p.m. (1815 GMT) the following day. Markets will be looking for any comment about how the Fed might wind down its financial stimulus measures, given the improving macroeconomic data.

The euro reached a one-year high against the U.S. dollar as dealers took advantage of the greenback's gains the previous session to resume selling ahead of the Fed meeting and a G20 summit later in the week. The dollar index <.DXY> tumbled 0.9 percent.

It is all a version of the carry trade where you (sell U.S.) dollars and turn around and buy the reflation trade that can be measured in stocks or in commodities, said Max Bublitz, chief investment strategist at SCM Advisors in San Francisco.

This is a continuation of what has been going on for the last months: as the dollar goes down, risk assets rally, he said.

Bublitz said the dollar is under pressure on concerns about the rising U.S. deficit and the government monetary stimulus. But if the Fed were to say the economy is doing better than expected, a rally based on a weak dollar would come to an end.

Crude futures rose 2.3 percent to $73.31 per barrel and copper for three-month delivery rose 2.2 percent.

Citigroup Inc shares rose 3.2 percent to $4.57 before the opening bell. The Government of Singapore Investment Corp (GIC) said it halved its stake in Citi through open market sales to below 5 percent.

S&P 500 futures rose 6 points and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures gained 45 points and Nasdaq 100 futures added 9.25 points.

Credit Suisse downgraded Dell Inc to neutral and recommended Hewlett-Packard Co , Apple Inc and EMC Corp . Dell shares fell 0.6 percent to $15.91 in premarket trading while Dow component HP rose 2 percent to $47.30.

Bank of America-Merrill Lynch upgraded U.S. Steel Corp to neutral from underperform, citing improved utilization, and raised its price target on the stock to $55 from $30. Shares rose about 3 percent to $49.40 before the bell.

Shares of Macy's Inc rose 5.2 percent to $18.72 after Citigroup upgraded the company to buy.

Data due on Tuesday at 10 a.m. include a home prices index and a regional manufacturing survey, giving investors further insight into the state of the U.S. economy. (1400 GMT).

Samsung Electronics <005930.KS>, the world's biggest maker of memory chips, said on Tuesday it remains cautious about the sector's outlook even as the industry emerges from its two-year slump.

The Dow industrials and the S&P 500 index fell on Monday as a drop in oil and other commodity prices hurt energy and materials stocks. But the Nasdaq rose, buoyed by a broker's upgrade in the biotechnology sector.

(Editing by Padraic Cassidy)