HONG KONG – Spot metallurgical coal topped $300 a metric ton for the first time since flooding in Australia curbed output from the world’s biggest seaborne exporter five years ago.

Hard coking coal rose to $307.20/t on Tuesday, extending a surge that has seen the price more almost quadruple since the start of June.

Miners and Japanese steelmakers agreed to a three-month supply contract at a record $330 for the second quarter of 2011 after heavy rain and flooding crimped production in Queensland. Chinese demand has driven the price surge this year.

China’s efforts to cut overcapacity in its coal industry have reduced domestic supply and boosted imports of both metallurgical and the variety burned in power stations. While Chinese purchases remained above 20-million tons in October for a fifth month, producers from BHP Billiton to Japan’s biggest trading houses predict prices will ease for coking coal.

“The impact on Chinese domestic supply has resulted in significant import demand,” said Daniel Hynes, an analyst at Australia & New Zealand Banking Group. “We could see prices slip about $150 lower than where they are at the moment, but I don’t think the market will be pushed in that direction in the short term. We’re just not expecting to see supply adjust that quickly.”

Spot hard coking coal advanced $17.90, or 6.2%, on Tuesday, according to data from The Steel Index. Monday’s rise was the biggest daily gain since the index was started in January 2013. Newcastle thermal coal increased 34% in October, the most since February 2008. Prices closed at $109.40 on Monday.

Japanese steelmaker Nippon Steel & Sumitomo Metal agreed to pay $200/t for metallurgical supplies during the fourth quarter, the highest contract price since 2012. Australian miner Whitehaven Coal and consultant Wood Mackenzie predict prices will remain at elevated levels in the short-term.

“Unless China decides to lift its restrictions and flood the market, you would expect prices to remain around these levels in the short to medium term,” Whitehaven chairperson Mark Vaile said in an interview Tuesday. Shares in the Sydney-based company have more than quadrupled this year.