Singapore Airlines Ltd., Southeast Asia’s biggest carrier, extended some of its fuel-hedging contracts to as long as five years, betting on an upswing in crude oil prices amid OPEC production cuts and renewed tensions between the U.S. and Iran. The marquee airline, which reported a 36 percent drop in profit for the three months through December, said Tuesday that it has entered into longer-dated Brent hedges with maturity extending to 2022.