AirAsia informed the Kuala Lumpur Stock Exchange on Thursday about the agreement, the Bernama news agency said.
The pact will allow Thai AirAsia X access to the AirAsia brand for the airline, it said.
"AirAsia, together with the experience of an on-going brand agreement with AirAsia X, has the necessary intellectual property to address this need," the filing said.
The agreement will last five years and be subject to renewal if the two firms agree, it added.
Thai AirAsia X planned to launch its long-haul, low-fare flights in March, but the plan was put on hold due to the political turmoil in Thailand.