China’s government declared two strains of genetically modified rice safe to produce and consume, taking a major step toward endorsing the use of biotechnology in the staple food crop of billions of people in Asia.

In a written reply to questions from The Wall Street Journal, China’s Ministry of Agriculture said Monday that it had issued safety certificates to domestically developed strains of genetically modified rice and corn, after a years-long process involving trial production and environmental tests. Further approvals are required before the strains can be grown on a commercial scale, the ministry said, and industry participants said it may take two to three more years for the rice to reach production.

Foreign companies that produce genetically modified crops welcomed the news. “It’s good news in the context of commercial introduction of biotechnology in crops in China,” said Andrew McConville, the Singapore-based head of corporate affairs in Asia for Syngenta AG, a Switzerland-based agribusiness firm.

China is the world’s top producer and consumer of rice, so its use of modified varieties has the potential to alter the grain’s global supply patterns. Widespread production has the potential to complicate trade with places such as Europe that restrict genetically modified foods.

On the other side, U.S. companies have been urging China to speed up its approval process for genetically modified crops.

Chinese officials have been less constrained by public pressure over the sometimes-controversial use of biotechnology in food than officials in other countries. The government has long supported research into agricultural biotechnology as part of a drive to ensure the nation remains self-sufficient in staple crops.