China's top economic planner, says coal companies should stick to the prices dictated in annual contracts.

The National Development and Reform Commission has directed major coal enterprises to stabilize domestic coal prices. And says those who have raised their price should revert to the agreed cost refunding any excess before the end of June.

Analysts say that even if coal prices stop rising, coal firms can still make big profits. China's biggest coal producer the Shenhua Group says it won't raise coal prices, and will stick to the contract price.