China's three largest airline cargo carriers will merge to form Asia's largest freight transport company, according to a senior official at the Civil Aviation Administration of China.

The three merging companies are Air China Cargo, China Cargo Airlines and China Southern Cargo, the official Xinhua on Wednesday night said, quoting deputy director Zhou Laizhen.

No timeline or valuation of the merger was provided.

Air China Cargo is a joint venture freight project between Air China Limited and Cathay Pacific Airways Limited. It has registered capital valued at 3.24 billion yuan ($528 million) and over 4,200 employees, according to its website.

China Cargo Airlines is a venture between China Eastern and China Ocean Shipping Company (COSCO). It has 950 million yuan in registered capital, according to its website.

China Southern Cargo is part of China Southern Airlines. – Reuters