China has fined retail giants Carrefour SA and Wal-Mart Stores Inc a combined 9.5 million yuan ($1.5 million) for manipulating product prices in some of their stores, the country's top economic planner said on Tuesday.

The National Development and Reform Commission said the penalty had been imposed on 19 outlets throughout the country, with each fined 500,000 yuan.

Last month, the planning agency said it would punish the two retailers after finding that some of their branches had either over-stated discounts by inflating pre-discount prices or charged higher prices than indicated on labels.

The purpose of this heavy punishment is to regulate the behaviour of market players and to protect consumer interests, so related enterprises should draw lessons from it, the NDRC said in a statement on its website (www.ndrc.gov.cn).