Malaysia said today it was terminating a search in the South China Sea for the missing airliner, and redeploying assets to two possible corridors in the Indian Ocean.

Prime Minister Najib Razak said the Beijing-bound MH370 flight had changed course and headed westward before its communication system was disabled.

He identified "a northern corridor stretching approximately from the border of Kazakstan and Turkmenistan to northern Thailand or a southern corridor stretching approximately from Indonesia to southern Indian Ocean," he said.

"We are ending our operations in the South China Sea and reassessing the redeployment of our assets," he said.

"We are working with relevant countries to request all information relevant to the search including radar data."