US regulators have set a 26 November deadline for opponents to file arguments against the proposed anti-trust immunity for members of the Star Alliance.
Ten members of the alliance, excluding US Airways, sought anti-trust approval from the Transportation Department earlier this year after Continental Airlines unveiled plans to jump to Star from the SkyTeam Alliance.
Immunity would allow the carriers to set joint fares and determine schedules and capacity, practices that are normally barred by the antitrust laws.
After arguments are collected later this month, the applicants have seven days to respond, but the agency does not have to rule on the Star Alliance request until 31 May, an agency spokesman says.
Oneworld carriers British Airways, American Airlines and Iberia are seeking similar immunity, but that proposed tie-up has triggered harsh criticism from several carriers including Virgin Atlantic, who argues those carriers would control roughly half the landing and takeoff slots at London Heathrow Airport. Delta Air Lines chief executive Richard Anderson has also argued that the three Oneworld carriers need to relinquish slots at Heathrow.