Traffic at airports operated by BAA rose by 2.5 percent in February, compared with the same period the previous year, with London's Heathrow benefiting from a surge in demand for flights to Brazil.
BAA, which is Britain's main airport operator and majority owned by Spanish infrastructure group Ferrovial, said on Monday that its airports carried 7.3 million passengers last month. The figure was inflated by an extra day because February was a leap year.
Nearly 4.8 million passengers passed through Heathrow, a rise of 3.8 percent on the year before.
"BAA's airports have continued to demonstrate their resilience in the weak economic environment we currently face," said BAA's chief executive Colin Matthews.
At Heathrow, the best performing destination was South America which saw passenger numbers rise 51.5 percent, with Brazil showing an increase of 89 percent.
Matthews said, however, that capacity constraints were in danger of preventing Britain's airports from adding new routes from other airlines which could bring jobs and growth to the UK. He noted that Britain's airports would add one new route to China this year compared to seven by European competitors.
"The centre of gravity in the world economy is shifting to emerging markets and we need to forge new links with them. Instead, because of capacity constraints, we are drifting towards a future where the UK will be cut off from some of the world's most important markets," Matthews said.
BAA said there was strong demand for all destinations except Britain and Ireland. North Atlantic flights were up 7.4 percent, with other long haul destinations up 1.3 percent.
Britain's Civil Aviation Authority said on Monday it had not found evidence Heathrow's airport charges were unreasonably discriminatory following a complaint from Lufthansa's UK unit bmi.
Bmi had complained Heathrow had discriminated against it and other short haul airlines on domestic services following changes to charges introduced in April 2011.