Brazilian oil workers have started a five day strike at the country's
main oil field, cutting production by at least 300,000 barrels per day.
Employees of Petrobras, Brazil's state-run oil company, are demanding additional pay. They say workers at 13 oil platforms in the Campos Basin are already participating in the strike.
Union leaders say they expect production at more than 30 of the region's 42 oil platforms to eventually come to a near standstill.
Drilling in the Campos Basin accounts for 80 percent of Brazil's crude oil output, and concerns about the strike at one point pushed the price of crude oil to more than $146 a barrel in New York trading Monday.
Oil prices hit a record high Friday of $147.27 a barrel in New York.
Some economists also point to concerns about violence in Nigeria and instability in the Middle East for helping to drive oil prices higher.
Meanwhile, Dutch-based oil giant Royal Dutch Shell has offered to buy Canada's Duvernay Oil Corporation for more than $5 billion.
Duvernay's operations have been focused on natural gas reserves in western Canada.
Some information for this report was provided by AFP, AP and Reuters.