Heathrow Group said with a third runway, the hub could handle 35 million more passengers per year in addition to the 70 million who already use the hub annually.
Without a third runway, Britain could be missing out on $41.2 billion each year by 2030 in lost trade, the group reported.
Currently, the airport's two runways operate at 99 percent capacity, a Heathrow Group report said.
The Daily Telegraph reported Thursday the airport, which is lobbying for permission to build a third runway, argues passengers are more willing to fly in and out of major hubs than outlying airports such as Stansted and Gatwick, even though those airports have more room to expand.
About a third of the passengers coming through Heathrow are connecting with other flights, which makes major hubs more practical and more appealing to passengers, the report says.
Heathrow Chief Executive Officer Colin Matthews said more capacity at Heathrow would allow London to win more business from emerging markets.