(Updates prices, adds London Brent, Iran comments)
By Felicia Loo
SINGAPORE, Jan 31 (Reuters) - Oil fell more than $1 to $91 a barrel on Thursday, roiled by worries of heavier financial losses that would drain the U.S. economy and hurt demand at a time when inventories of crude and gasoline are rising quickly.
U.S. light crude for March delivery <CLc1> dropped $1.09 or about 1.2 percent to $91.24 a barrel by 0703 GMT, reversing a gain of 69 cents on Wednesday's close.
London Brent crude <LCOc1> lost $1.06 a barrel to $91.47.
"People are looking at the U.S. crude oil stocks, which rose heavier-than-expected and they are also worried about the equity markets," said Tetsu Emori, a fund manager at Astmax Co Ltd in Tokyo.
U.S. stocks fell on Wednesday, reversing strong gains after the Federal Reserve slashed interest rates, after speculation on financial television network CNBC that credit rating firms would downgrade one or both of the two U.S. biggest bond insurers.]
A credit downgrade could further harm the bank sector and stunt the global economy as financial institutions take a hit from subsequent writedowns of their assets.
The U.S. Fed cut rates by a hefty half-percentage point to 3 percent, the lowest since June 2005, and came just eight days after the central bank slashed rates by three-quarters of a point. The aggressive efforts were to halt a sharp slowdown in an economy hit by a housing slump and a credit crunch.
A U.S. government report on Wednesday that showed a rise in U.S. crude stocks, also brought prices down.
The Energy Information Administration said U.S. crude stocks rose 3.6 million barrels last week to 293 million barrels, rising for the third consecutive week, as opposed to a forecast poll of 2.4 million-barrel build. [
]Gasoline stocks also rose 3.6 million barrels to 224 million barrels, their highest level since February 2007, while distillate stocks fell 1.5 million barrels to 127 million barrels.
The forecast was for a lower build in gasoline at 1.9 million barrels and distillates to fall 1.7 million barrels.
The fact that the fall in distillate stocks was less than expected signalled declining oil consumption in the United States at a time of peak seasonal demand for heating.
But oil prices are expected to stay above $85 a barrel, on a monthly basis, through June, even if OPEC keeps output close to current levels when it meets this week, the EIA said on Wednesday.
Iran Oil Minister Gholamhossein Nozari said on Thursday oil markets were well supplied and he saw no need for the Organization of the Petroleum Exporting Countries to boost production at its meeting on Friday.
Hojjatollah Ghanimifard, international affairs director at the National Iranian Oil Co told the daily Iran newspaper there was no need for OPEC to increase output, as warmer spring weather was approaching and extra crude would not bring down prices. (Editing by Ramthan Hussain)