Administrators have confirmed US company Air T is planning to buy troubled Australian carrier Rex 15 months after it collapsed into administration. But University of Sydney transport and supply chain expert Rico Merkert said there were few markets into which Rex could expand. He also suggested the buyout could lead to cheaper flights on some regional routes because the business would be operating more smoothly post-administration. Transport Workers Union national secretary Michael Kaine said there were still significant questions about Rex's long-term future. Opposition transport spokeswoman Bridget McKenzie said the government needed to clarify which routes Rex would operate under its new ownership and whether prices would change.