Qantas will start selling tickets within weeks for flights to Europe via Emirates' Dubai hub.
The Australian Competition and Consumer Commission (ACCC) on Thursday gave Qantas and Emirates the green light to prepare joint sales, marketing and pricing strategies for the two airlines' partnership.
Under the alliance, Dubai, rather than Singapore, will be the stop-off for all Qantas flights into London.
The Flying Kangaroo will codeshare with Emirates on flights to Europe, North Africa, the Middle East and Asia as well as across the Tasman.
Qantas hopes to have fares available within weeks for flights on the two airlines' combined networks from April 1.
ACCC chairman Rod Sims said the regulator granted interim authorisation because of the long lead time required to market and sell tickets before the start of long haul services.
Qantas chief executive Alan Joyce says the ACCC ruling will allow customers to buy tickets for travel on most parts of the combined Qantas and Emirates network.
"This decision means we can determine pricing, capacity and scheduling with Emirates, in addition to the more logistical aspects of the partnership that we have been working through already," Mr Joyce said in a statement.
With interim authorisation, Qantas will be able to sell one-stop itineraries from Australia where passengers will be transferred onto Emirates aircraft in Dubai to European destinations not served by Qantas aircraft, such as Milan, Manchester, Munich or Madrid.
The ACCC said the two carriers will not be able to commence planning on those services as part of the interim authorisation.
The ACCC had previously expressed concern the Qantas-Emirates tie-up would give the two carriers an increased ability or incentive to reduce or limit capacity across the Tasman to raise airfares.
Therefore, the pair would be required to, at first, maintain and then increase capacity on four trans-Tasman routes.
Qantas has said previously its international operations were in "terminal decline" as it was unable to compete effectively with mid-point carriers based in the Middle East and Asia, given their geographic and economic advantages.
The alliance was regarded as a key plank of Mr Joyce's bid to turn around the Flying Kangaroo's international operations, which reported a $216 million loss in 2010/11 and $450 million loss in 2011/12.
The ACCC was expected to hand down its final decision in March.
At 1530 AEDT, Qantas was down two cents at $1.52.