NEW YORK (Dow Jones)--Crude futures fell Monday, as fraud charges against Goldman Sachs reduced investors' risk appetite, and a volcanic eruption sharply reduced European jet fuel demand.

"You've got two dark clouds in the system right now," said Tony Rosado, a broker with GA Global Markets.

Light, sweet crude for May delivery recently traded $2.32, or 2.8%, lower at $80.92 a barrel on the New York Mercantile Exchange. Brent crude on the ICE futures exchange traded $2.47, or 2.9%, lower at $83.52 a barrel.

The oil market is coming out as one of the biggest losers since the Securities and Exchange Commission charged Goldman Sachs Group Inc. (GS) on Friday with misleading investors in marketing certain financial instruments tied to subprime mortgages. While Goldman is one of the largest financial institutions active in oil trading, the main downward pull is coming from investors exiting riskier markets to protect against any impact from the charges to Wall Street trading operations. The SEC is investigating other large firms for similar practices, the Wall Street Journal reported Monday.

Oil prices have fallen about 5% since the charges were announced Friday.

May copper futures were down 1.1% at $3.4810 a pound, while European and Asian equities markets were also lower. The dollar, often a safe haven for risk-averse investors, was up against the euro at $1.3430, from $1.3499 earlier. A stronger dollar can depress oil prices by making crude more expensive to purchase using other currencies.

The oil market is also adjusting to the shutdown of air travel across much of Europe by ash from a volcanic eruption in Iceland. Airports from Ireland to Ukraine remain closed to most air traffic Monday, with reopenings depending on prevailing winds and the length of the eruption.

The grounded flights will cut jet fuel demand by about 1 million barrels a day, or just over 1% of total world oil demand, several analysts said. That amount is generally seen as enough to put pressure on oil prices in the short term, but too small to reduce oil prices once the ash cloud dissipates.

"The implications for the oil market are myriad, but currently do not convince us that our positive outlook on markets is wrong, despite these intensifying headwinds," wrote analysts with JPMorgan Chase & Co.

Front-month May reformulated gasoline blendstock, or RBOB, recently traded 4.75 cents, or 2.1%, lower at $2.2295 a gallon. May heating oil traded 7.06 cents, or 3.2%, lower at $2.1463 a gallon.

-By Brian Baskin, Dow Jones Newswires; 212-416-2453;