The cost of oil has begun rising once again after two months of falling prices. A barrel of crude was at more than $62 in early trading on Friday, higher than in recent days, but well below the $78-plus mark of a couple of months back. The latest upward shift is said by analysts to be based on speculation that most of the major oil-producing countries, members of OPEC, are about to limit supply in order to push oil prices back up to more profitable levels. Nigeria has already cut output, and several OPEC nations are suggesting they want to follow suit. Should more countries implement production reductions, oil prices are likely to see sharp rises.