China's imports of liquefied natural gas rose 29 percent in the first half of 2012 from a year earlier while purchases of coal climbed 61 percent, according to the Beijing-based General Administration of Customs.

LNG supplies increased to 6.7 million metric tons through June this year with the delivered unit cost of the fuel at $549 a ton, or $11.30 per million British thermal units, according to the data. Coal imports, excluding lignite and including metallurgical coal, climbed to 113 million tons, delivered at an average of $118.55 a ton.

Crude futures, used to price contracted supplies of LNG, averaged $113.61 a barrel in London in the first half, which in calorie equivalent terms was about $19.59 per million Btu.

Purchases of LNG in June rose 16 percent to 1.21 million tons at $602 a ton compared with a year earlier, according to the data. The country bought 120,000 tons of the fuel from Nigeria at about $899 a ton. That's equivalent to $18.50 per million Btu.

The country paid $511 a ton in May for LNG purchases and about $21 per million Btu for a spot purchase from Russia, according to customs data. Piped gas volumes from Turkmenistan increased by 58 percent in the first half to 7.28 million tons at $552 a ton.

Coal purchases climbed 65 percent in June from a year earlier to 22.53 million tons, according to the data. That cost an average $115 a ton.