Airlines are returning to the skies from some of Australia's largest airports on Wednesday as a volcanic cloud that has forced two days of flight cancellations clears over southern Australia.

Australian flagship carrier Qantas and rival Virgin Australia resume early morning flights from the southern city of Adelaide on Wednesday.

Qantas and its budget subsidiary Jetstar have told customers that flights through Melbourne, Australia's second largest city, and the national capital, Canberra, will resume late morning with Virgin returning to the air by noon.

In Sydney, Australia's largest city, and neighboring Newcastle, Qantas, Jetstar and Virgin will resume services Wednesday afternoon.

Greyhound is running extra bus services in Adelaide, Melbourne, Canberra, Sydney and Brisbane to help move a backlog of stranded passengers, while trains between Brisbane, Sydney and Melbourne had added rail cars.

Civil Aviation Safety Authority spokesman Peter Gibson said it was possible all flight schedules would return to normal on Thursday.

Ash from the Cordon Caulle volcano grounded hundreds of flights and stranded tens of thousands of passengers last week when it hovered over several Australian cities and New Zealand. By Friday, all flights were running normally, but the ash has lapped the globe and is causing more problems.

Chile said Sunday that the Cordon Caulle volcano, which began erupting June 4, was becoming less active.