The proposal will be put to stakeholders such as the airlines, airport-related businesses, border agencies, regulatory authorities and local, state and federal governments.
It will be considered in the context of the airport's 2014 master plan process, which is scheduled to begin in late 2013.
Qantas chief executive Alan Joyce said the plan responded to the challenges and opportunities facing Sydney Airport.
"The proposed new terminal precinct would have significant benefits for all passengers travelling with both Qantas and Jetstar," Mr Joyce said in the statement.
"As passenger numbers grow over the next decade, it is vital that airlines and airports work closely together to deliver a seamless travel experience.
"We look forward to exploring all aspects of the concept in detail during the consultation period."
Virgin Australia chief executive John Borghetti said he supported any proposal that would improve services to the travelling public and would grow tourism in Australia.
"We believe there is potential in Sydney Airport's proposal," he said.
- AAP