More than 130 companies are planning to invest a total of 49.8 billion yuan (about $8.1 billion) in projects in Northwest China's Xinjiang Uygur autonomous region, the region's investment promotion authority has said.

The companies belong to 16 provincial-level enterprise associations or chambers of commerce across China, according to a statement by the Xinjiang regional merchants and development bureau after an investment promotion fair was held in Xinjiang's Tacheng Prefecture, which borders Kazakhstan.

The region has signed with the companies seven investment agreements worth 7.17 billion yuan in coal mining, logistics, real estate and border trade sectors.

Investment details of another 23 projects worth a total of 42.63 billion yuan are still being discussed, according to the investment promotion bureau.