They also said they were confident that the plane was flying on autopilot when it crashed.
Transport Minister Warren Truss told reporters in Canberra on Thursday that the new search area is based on fresh analysis of existing satellite data from Malaysia Airlines Flight 370.
The plane vanished during a flight from Kuala Lumpur to Beijing on March 8 with 239 passengers and crew aboard.
The shift was expected. The head of the Australian Transport Safety Bureau said last week it would move south of an area where a remote-controlled underwater drone spent weeks fruitlessly scouring 850 square kilometers of seabed.
Martin Dolan, chief commissioner of the Australian Transport Safety Bureau, said “certainly for its path across the Indian Ocean, we are confident that the aircraft was operating on autopilot until it ran out of fuel.”
Truss said officials have not attempted to fix a moment when the plane was put on autopilot.