US STOCKS-Wall Street set to rise, investors on Fed watch
* Mosaic, Potash Corp tumble after Russia quits top potash cartel
* Sprint posts wider quarterly loss even as revenue rises
* Aetna profit, Pfizer earnings beat expectations
* Futures up: Dow 31 pts, S&P 4 pts, Nasdaq 13 pts
NEW YORK, July 30 (Reuters) - U.S. stocks were set to rise slightly at the open on Tuesday, bouncing back from a decline on Monday, as investors braced for consumer data in a week packed with economic numbers and a Federal Reserve policy statement.
Volume could be subdued before the Fed statement on Wednesday at the end of a two-day meeting of policymakers. The Fed's Open Market Committee's statement will be combed for hints of when the central bank may begin to scale back its $85 billion a month in asset purchases aimed at stimulating the economy.
The week is also heavy with earnings reports. Tuesday's highlights include health insurer Aetna and pharmaceutical company Pfizer, which reported profits that exceeded expectations.
"Earnings are being consistent with what the market has been expecting and we are on Fed watch, so we'll probably have a range-bound market, possibly regaining yesterday's losses," said Peter Cardillo, chief market economist at Rockwell Global Capital in New York.
He said besides the Fed statement, investors are bracing for Friday's payrolls report as it may decide the Fed's next move.
Non-farm payrolls are expected to have risen 184,000 in July, according to a Reuters survey.
With results in from more than half of the S&P 500 companies, 67.2 percent have beaten earnings expectations - in line with the 67 percent average beat over the last four quarters. About 56 percent of the companies have beaten revenue expectations, more than the 48 percent of revenue beats in the past four earnings seasons, Thomson Reuters data showed.
S&P 500 futures rose 4 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 rose 31 points, and Nasdaq 100 futures added 13 points.
Shares of Mosaic Co tumbled 26 percent in premarket trading after Russia's Uralkali dismantled one of the world's largest potash partnerships by pulling out of a venture with its partner in Belarus, a move it expects will cause global prices to plunge by 25 percent.
Intrepid Potash shares plunged 24 percent while U.S-traded shares of Potash Corp fell 23 percent and Agrium lost 7.6 percent.
Mobile service provider Sprint Corp posted a wider quarterly loss on costs from shutting down its Nextel network, but revenue grew as customers spent more on wireless services. Shares rose 2.3 percent in premarket trading.
Herbalife shares rose 8.1 percent premarket a day after the nutritional products company said its better than-expected earnings and rosy 2013 outlook were driven by a fast-growing global distributor network and strong demand for its weight-loss shakes and supplements.