CHINA'S top economic planner has fined two companies for monopolizing the sales of the base ingredient used to make drugs that treat high blood pressure.

The National Development and Reform Commission fined Weifang Shuntong and Weifang Huaxin - both headquartered in Shandong Province - more than 7 million yuan (US$1.1 million).

A statement on the NDRC website said yesterday that the two companies signed a contract on June 9 with the country's only two makers of promethazine hydrochloride, the base ingredient for making high blood pressure pills. The contract forbade the two manufacturers from selling the ingredient to a third party without approval from them.

The two firms then raised the base ingredient's price to as much as 1,350 yuan per kilogram from 200 yuan. Many producers of high-blood pressure pills were forced to halt production due to the high prices of the ingredient, the NDRC said.

Their monopoly also caused tight supplies of the medicine in the market.

The NDRC has ordered the two firms to stop their illegal activity and to cancel the contract with the two makers.