Oil fell by $2 to around $143 a barrel this morning as the dollar rebounded following a United States plan to restore confidence in its financial sector.
The US government at the weekend unveiled an emergency plan to shore up embattled mortgage giants Fannie Mae and Freddie Mac - which control $5 trillion in debt - easing concerns about the wider economy and helping the dollar bounce off its near-record against the euro.
US light crude for August delivery was $1.76 down at $143.32 a barrel by 10am. London Brent crude was $1.59 down at $142.90.
US crude hit a record high of $147.27 last Friday, as concerns about threats to global oil supplies and a deteriorating US economic landscape hit financial markets, driving investors to seek the relative safety of commodities.
Oil initially fell by more than $2.50 today, but pared those losses as Brazilian oil workers began a five-day strike, once again highlighting supply fears in a tight market.
Traders were also on the watch for any news of supply disruptions from Nigeria, where militants abandoned a ceasefire, and from Iran amid tensions with Israel and the west.
"Oil's fall this morning is generally due to gains in the US dollar as well as some profit-taking in the market," said Gerard Burg, a commodities analyst from the National Australian Bank in Melbourne.
Oil prices have risen sevenfold since 2002 on surging demand from China and other emerging markets, and have jumped 50 percent this year alone, battering the economies of consumer nations already hit hard by the global credit crunch.
Supply concerns again came to the fore as Brazilian oil workers at the national energy giant Petrobas began a planned five-day strike at the country's key fields in the Campos basin at midnight yesterday.
Campos accounts for more than 80 per cent of Brazil's crude output of 1.8 million barrels per day.