Much has been made of the falling value of the Pound since Britain’s decision to leave the EU, which has provided a major boost to British exporters.
This in turn has seen export focused ports across the UK such as Heathrow reap the benefits.
Heathrow recorded a 6% increase in the amount of cargo it handles during September compared with the same month last year fuelled by markets in East Asia and Latin America.
Goods being flown to and from Brazil were up 18%, China up 13% and Mexico up 7%, according to figures published by the airport.
Heathrow describes itself as "Britain's largest port" and said it accounted for almost 30% of all UK exports by value outside the EU last year while Gatwick handled only 0.2%.
Both airports are hoping to be given the green light to build an additional runway and the government is expected to make a decision in the coming days.
Heathrow chief executive John Holland-Kaye said: "The Prime Minister is clear that her government will step up and do what's right for Britain.
"Expanding our country's largest port will give Britain's businesses the best connected trading network in the world. We'll show that we're confident about our future and determined to make a success of Brexit.
"We've had the debate on airport capacity, we've heard all the arguments and the independent evidence is conclusive - Heathrow expansion will make Britain stronger and fairer for everyone. Now is the time to make the right choice for Britain and back Heathrow."
The Airports Commission recommended in July last year that a third runway should be built at Heathrow, which it described as "operating at capacity."
Heathrow's figures show that the number of passengers who used the airport last month grew 0.4% year on year.
A spokesman for the airport said: "Larger, quieter and more efficient aircraft continued to be a driver for growth in passenger volumes... as airlines deploy more and more new generation Airbus A380s, A350s and Boeing 787s at Heathrow."
On Monday, the Scottish Government backed a third runway at Heathrow, with ministers claiming it would provide new jobs and more flights to and from Scotland.
Gatwick said it was "surprised" at the announcement and claimed Heathrow's proposal would "undermine Scotland's connections with the world."
A spokesman for the West Sussex airport added: "We are confident that expansion will happen at Gatwick and that competition will prevail over the old-fashioned monopoly being planned by Heathrow."