It provided no details of the deal; Kazakh news website lsm.kz cited QazaqGaz as saying the deal covered supplies between 2023-26.
Kazakhstan has been exporting gas to China for years, although it has reduced the volume supplied, at first due to lower demand and then because of increasing domestic consumption.
However, this month Russia, largely cut off from European markets, started exporting gas to Kazakhstan and Uzbekistan, which could allow Astana to free up more of its own gas for export.