Emirates and Etihad Airways will share information and intelligence after signing a security pact on Monday.
The agreement — which is the first between the two airlines — involves Emirates Group Security and Etihad Aviation Group working "together on operational areas both within and outside the UAE," according to an Emirates statement.
The agreement was signed by Emirates president Tim Clark and Etihad's new group chief executive Tony Douglas.
In October last year, Mr Clark said Emirates was open to working with Etihad, including on procurement.
"I think there is value to be had working more closely with them," he said.
Under Monday's agreement, Emirates Group Security will provide security and training programmes to Etihad and help develop their security escort capability.