Wedbush Securities analyst Michael Pachter estimates that Modern Warfare 3 and Battlefield 3 will generate more than $1.4 billion by the end of the year.
Speaking to Forbes, Pachter claimed that EA and Activision's rival franchises will account for 15 per cent of all revenue in the fourth quarter.
Modern Warfare 3 will be responsible for the majority of that amount, selling 16 million units worldwide versus Battlefield's 8 million. That trend will continue in 2012, when Pachter expects Modern Warfare to sell an additional 8 million units versus Battlefield's 2 million.
"I'd guess that around half of the console copies of Battlefield 3 will be bought by people who also buy Modern Warfare 3, so around 2 to 3 million will buy both," Pachter added. "I don't see much cannibalisation of the titles."
The competition between Battlefield 3 and Modern Warfare 3 led to public recriminations between EA and Activision, with the latter accusing the former of "mud-slinging tactics."
Battlefield 3 launches in the US tomorrow, with the European launch to follow on Friday. Modern Warfare 3 will be released worldwide on November 8.