GLOBAL MARKETS-Earnings boost stocks; Greece weighs on euro

* World stocks rise 0.8 pct on Goldman's strong profits

* Dollar down, commodities up as appetite for risk grows

* Lingering Greece concerns weigh on euro

By Walter Brandimarte and Jessica Mortimer

NEW YORK/LONDON, April 20 (Reuters) - Positive corporate earnings results and optimism about the global economy boosted stocks on Tuesday, while reducing the safe-haven appeal of the U.S. dollar and Japanese yen.

The euro weakened against the dollar on concerns Greece might need a large aid package.

Commodity prices rose as optimism about the global economy encouraged investors to take on risk. That sent emerging market stocks more than 1 percent higher.

The sentiment improved as Goldman Sachs Group Inc posted above-forecast quarterly results which deflected attention from fraud accusations against the bank by U.S. securities regulators. [ID:nASA008KM]

Citigroup Inc announced its best quarterly results in nearly three years. Other companies such as International Business Machines Corp and Coca-Cola Co failed to impress investors with less stellar earnings.

"Earnings overall are good, but you better beat these heightened expectations or else your stock is going to take a breather after the run we've had going into earnings," said Peter Boockvar, equity strategist at Miller Tabak & Co in New York.

The MSCI world equity index <.MIWD00000PUS> gained 0.8 percent but Wall Street was trading little changed after rising at the opening.

The Dow Jones industrial average <.DJI> edged down 5.67 points, or 0.05 percent, to 11,086.38. The Standard & Poor's 500 Index <.SPX> climbed 3.69 points, or 0.31 percent, to 1,201.21. The Nasdaq Composite Index <.IXIC> was up 1.81 points, or 0.07 percent, at 2,481.92.

In Europe, the FTSEurofirst 300 index <.FTEU3> of top shares rose 1.3 percent, with banking stocks among the top gainers.

"Results have driven shares higher. After a couple of down days Citi came out with stellar results and people started buying again," said Mic Mills, senior trader at ETX Capital.

The MSCI index of emerging market stocks <.MSCIEF> gained 1.1 percent as commodity prices rose.

U.S. crude oil rose $1.35, or 1.66 percent, to $82.80 per barrel, and spot gold prices rose 0.58 percent to $1,141.10 an ounce. The Reuters/Jefferies CRB Index <.CRB> of commodity futures gained 0.72 percent.

GREECE CONCERNS WEIGH ON EURO

Greater risk appetite hurt the U.S. dollar, which was trading nearly stable against a basket of major currencies, according to the U.S. Dollar Index <.DXY>.

Against the Japanese yen, the dollar was up 0.61 percent at 92.99.

The euro weakened 0.23 percent to $1.3453 dollars as concerns about Greece's fiscal situation lingered, causing the premium investors demand to buy Greek government bonds compared with euro zone benchmark Bunds to rise to fresh highs.

The yield spread between Greek and German 10-year bonds widened to 489 basis points, a euro lifetime wide, versus 468 basis points at Monday's settlement close, according to Tradeweb.

The Wall Street Journal reported European Central Bank Governing Council member Axel Weber said Greece may require assistance of up to 80 billion euros. [ID:nLDE63J0BJ]

Greece has yet to ask for activation of the EU/IMF aid safety net agreed earlier this month, estimated at 45 billion euros in the first year. [ID:nLDE63I1J1] (Editing by Andrew Hay)