VCCP was also involved in the process at an earlier stage. The pitch was handled by the AAR.
It is understood that M&C Saatchi was stood down last week after work from the three final pitching agencies went through research.
Fallon remained in conversations with Foster's until yesterday when Adam & Eve was awarded the account.
The appointment of Adam & Eve puts an end to M&C Saatchi's 14-year relationship with the beer brand. The agency picked up the business just a year after its launch in 1996.
Although M&C has created a number of iconic ad campaigns for the Heineken UK-owned brand under the strapline "drink Australian, think Australian", its recent work, which ran with the end line "get some Australian in you", is thought to have been less successful.
The win marks the second time the beer brand has put its faith in a young agency – Adam & Eve launched just two years ago.