The pipeline is the first significant gas link connecting the former Soviet region with eastern markets while bypassing Russia. Russian gas monopoly Gazprom is currently the main buyer of Central Asian gas.

"The first gas will be shipped in late November 2009," said Beimbet Shayakhmetov, the head of the Asian Gas Pipeline company, a joint venture set up by China and Kazakhstan to build the link.

"In 2010, we will transit about 4.5 billion-5.0 billion cubic metres of gas from Turkmenistan," he told reporters at the construction site near the country’s commercial hub of Almaty.

The Kazakh segment is part of a route that links Turkmenistan’s natural gas deposits with China via Uzbekistan and Kazakhstan. Other parts of the pipeline are yet to be completed.

Turkmenistan is Central Asia’s largest gas producer. Shayakhmetov said China and Uzbekistan, the region’s second-largest, were also in talks on supplying the pipeline.

By 2013, the 6,500-km (4,000-mile) pipeline is due to ship 30 billion cubic metres (bcm) of gas to China annually. In addition, Kazakhstan plans to receive 10 bcm via the pipeline for its own needs.

China has not disclosed the total cost of the project. Shayakhmetov said the Kazakh segment cost US$4 billion to build.

His company will spend US$3.5 billion more to extend the pipeline to Kazakhstan’s own gas fields, located close to the Caspian Sea coast.