BEIJING - The National Development and Reform Commission (NDRC), the country's top economic planner, announced Friday that it has ordered two sugar-making companies from the southern autonomous region of Guangxi to stop hoarding, a practice blamed for pushing up prices.

The two sugar makers are Guangxi Nanhua and Guangxi Fengtang, both of which were found to have substantially large inventories of sugar during inspections by the NDRC to more than 10 sugar companies in the nation's major sugar-producing regions.

The hoarding by the two companies amounted to 170,000 tons, according to an NDRC statement on its website.

"Their massive hoarding has led to the sharp rises of sugar prices and caused tight supplies in the market. The practice has violated price laws and regulations," the statement said.

Since 2009, sugar prices have been increasing rapidly in the country due to reduced output and rising production costs. However, illegal hoarding and price-fixing also led to price rises, the statement said.

The NDRC has ordered the two companies to sell their hoarded sugar at a price of no more than 7,000 yuan ($1,100) per ton to the market before October 15.

The companies will be fined according to the law if they fail to do so, the statement said.

Further, the NDRC has ordered local bureaus to step up checks over major sugar-producing companies and to crack down on hoarding and price fixing.

According to a report published by the NDRC, the price of sugar in Nanning, capital city of Guangxi, one major sugar-producing area in China, was 7,660 yuan per ton at the end of August -- down from a peak of 7,721 yuan per ton on August 18.