Power-station coal prices at Australia's Newcastle port, a benchmark for Asia, snapped a five-week losing streak to rise 5 percent after a storm damaged Vietnam's largest harbor and cut exports.

The weekly index of thermal coal prices at the New South Wales port gained $7.74 to $163.90 a metric ton in the week ended Aug. 15, according to the globalCOAL NEWC Index. Prior to that, the measure had dropped 20 percent from a record $194.79 a ton reached in the week ended July 4.

Prices of the fuel may rebound after a cyclone damaged the Cam Cha port in Vietnam, the largest supplier of coal used in power stations to neighboring China, analysts at Macquarie Group Ltd. said in an Aug. 8 report. Vietnam accounts for about 3 percent of global seaborne coal supply and the port closure may cut exports by as much as 12 million tons, they wrote.

``It is still digesting lower Vietnamese coal this year,'' said Mark Pervan, a senior commodity analyst at ANZ in Melbourne. Thermal coal is still the bank's preferred commodity, it said today in an e-mailed report.

Xstrata Plc, the world's largest exporter of power-station coal, BHP Billiton Ltd. and Rio Tinto Group are among mining companies that ship coal through Newcastle.

The weekly globalCOAL index is up 83 percent so far this year. The monthly index for July gained 13 percent to $184.51.

``When you look at the fundamentals for thermal coal versus other commodities, it stacks up the best out of any of them,'' Pervan said today. ``It really comes down to tightening Chinese supply and that's the one market where China's tightening supply has a big influence on prices.''