Three mainland power firms have signed long-term supply contracts with coal producers that set higher prices for the key commodity. The price increases were largely in line with state-guided levels and come after the central government allowed electricity tariffs to move along with coal prices for the first time since the coal market was deregulated two years ago. A spokesman for Beijing Datang Power Generation said the company had signed contracts for 14 million tonnes of coal, amounting to about 80 per cent of its estimated demand for this year. The average contract price was 12 yuan per tonne higher than last year's level. A spokesman for Huaneng Power International said the firm had signed contracts for about 65 per cent of its forecast demand at an average price increase of 12 yuan, but declined to state the volume. Huadian Power International will pay 13 yuan per tonne more this year. It signed contracts for six million tonnes, or 50 per cent of its estimated need for this year. The increases were in line with guidelines set by the National Development and Reform Commission. Deputy director Zhang Guobao has said prices should not rise more than 12 yuan per tonne. Last year, coal producers and power firms could not agree on a price for most of their contracts, resulting in the commission stepping in to work out a settlement. The contract agreements demonstrate that the government maintains a co-ordinating role in the determination of coal prices. Analysts said they also showed the government would allow power firms to raise tariffs to offset higher coal costs as it did not want to scare investors away from the sector, which needs new plants to ease the chronic electricity shortage.