Crude oil prices dropped Friday on the New York Mercantile Exchange with prices down more than 20 percent in the past week and headed toward $40 per barrel....
The president of state-owned energy giant Petrobras said Friday that current oil prices won't halt investments in the development of Brazil's pre-salt layer oilfields. Crude oil prices plunged to a four-year low of about 40 U.S. dollars per bar...
