Tanker operators are expecting bigger profit margins as low oil prices slash the cost of fuel and encourage traders to ship more crude around the world. Current-quarter gains for shipping companies such as Teekay Tankers Ltd and DHT Holdings Inc could last until the middle of next year as oil prices - currently at four-year lows - remain depressed. Oil has lost more than a third of its value since June. U.S. crude dipped below $70 a barrel on Thursday after Saudi Arabia blocked calls for output reductions from some members of the Organization of the Petroleum Exporting Countries. Traders are profiting by moving cheaper oil to Asia, where it is sold at higher prices. “The decline in oil prices, and the fact that there is so much oil that needs to move, has resulted in long-haul arbitrage opportunities,” said Anthony Gurnee, chief executive of Ardmore Shipping Corp. “Ships are engaged in very long voyages now.” After three years of oversupply, tankers are now in demand. Rates for very large crude carriers (VLCC) rose five-fold between early June and the beginning of this month. They jumped 80 percent for midsized Suezmax tankers and more than doubled for smaller Aframax tankers. Partly because of these higher rates, analysts have raised their current-quarter estimates for the core earnings of several shipping firms. This month, they have raised their fourth-quarter estimate for Teekay’s earnings before interest, tax, depreciation and amortization (EBITDA) by an average 32 percent, according to Thomson Reuters I/B/E/S. The average EBITDA estimate for Nordic American Tanker Ltd has risen about 44 percent this month. Teekay’s stock has gained nearly 23 percent since June, while Nordic American’s has climbed about 8 percent. Lower oil prices have also slashed the cost of marine fuel. For every $10 drop in the oil price, the cost of marine fuel to Teekay drops by about $2,400 a day, CEO Kevin Mackay said on a conference call this month. Gurnee, speaking to Reuters, said low fuel costs were boosting Ardmore’s earnings “by a couple of thousand dollars per day”. Tsakos Energy Navigation Ltd said last month that the lower oil price would save it about $10 million annually in fuel costs.