Virgin Blue group and Delta Air Lines will seek regulatory approval to form a comprehensive joint venture.
In a joint statement the Australian and US carriers say the deal will expand their reach "between the USA and Australia and the South Pacific."
The deal includes collaboration on routes and product planning and the carriers will place their codes on each other's flights, it says. Each carrier will extend frequent flyer programme benefits and lounge access to the other's customers, it adds.
Prior to the joint-venture, the statement says the two carriers already started to implement codesharing, frequent flyer reciprocity and lounge exchange privileges. The two airlines will also file for antitrust immunity with the US Department of Transportation and the Australian Competition and Consumer Commission, it adds.
Delta commenced daily non-stop services on the Los Angeles-Sydney route on 1 July with a Boeing 777-200LR. V Australia, a unit of Virgin Blue, also operates daily Boeing 777 services on the Los-Angeles Sydney route as well as three flights weekly on the Brisbane-Los Angeles route.