* U.S. gasoline stocks fall, crude and distillates rise-EIA
* Spain credit rating downgraded by S&P, Markets fluctuate
* Fed pledges to keep rates low, sees US economic growth
* Traders focus on spreads, Brent premium near 8-mth high
(Recasts, adds Fed, settlement prices)
By Joshua Schneyer
NEW YORK, April 28 (Reuters) - Oil rose on Wednesday as falling U.S. gasoline stocks and an upbeat Federal Reserve assessment of U.S. economic growth prospects offset investor concern about Europe after Standard & Poor's downgraded Spain's credit rating.
The Fed said it will keep interest rates low for an extended period and pointed to signs of strength in the economy, which also supported U.S. stocks. [
] [ ]"The U.S. economy shows signs of improvement, according to the Fed, and that's clearly positive for the oil market," said Gene McGillian of Tradition Energy in Stamford, Connecticut. "With interest rates low as they are, equities and commodities are attractive to investors without other alternatives.
Gasoline stocks fell unexpectedly in the United States last week even as refineries ramped up operations, the U.S. Energy Information Administration reported in weekly data, one sign of recovering demand from motorists in the world's largest consumer. [
]U.S. crude for June delivery <CLc1> rose 78 cents a barrel to settle at $83.22 a barrel. London Brent for June delivery <LCOc1> ended up 38 cents at $86.16 a barrel.
Market focus was on spread trading as front month Brent was boosted earlier to its highest premium over the West Texas Intermediate contract in more than eight months, of $3.65, on fears a crude glut in the U.S. Midwest would continue to weigh on WTI.
U.S. crude stocks and distillate stocks last week rose nearly double what analysts had forecast, according to EIA data.
Oil stocks in Cushing, Oklahoma, the delivery point for the New York Mercantile Exchange futures, rose for a sixth straight time last week. But the rise was a modest half a million barrels, which narrowed the discount for front-month U.S. crude contract to the next month to $2.42 a barrel.
The discount, known as contango, has been driven in part by a rapid rise in oil stocks in Cushing and on Tuesday, hit its widest settlement level since December at $2.56 a barrel.
The jump in distillates stocks also weighed on the U.S. heating oil crack <CL-HO1=R>, which narrowed from an 11-month high reached on Tuesday. The price difference between crude and heating oil has unseasonally doubled in the past month. [
]Standard & Poor's downgraded Spain's credit rating the day after the agency downgraded Greece and Portugal, pressuring the euro to a one-year low against the dollar, before it rallied on the Fed statement.[
]Oil and other dollar-denominated commodities tend to move in the opposite direction to the greenback, as a weaker dollar makes them cheaper for other currency holders and vice versa.
"(The downgrade) doesn't portend to things looking rosy," said McGillian. "As long as these worries are still playing out in Europe, the dollar is going to get stronger and oil prices could be under pressure." (Additional reporting by David Sheppard in London, Gene Ramos in New York, Karl Plume in Chicago and Alejandro Barbajosa in Singapore; Editing by Marguerita Choy)