State-owned airport operator Airports Company South Africa (ACSA) reported a 10.8 percent rise in full-year profit on Monday, lifted by growth in international traffic.

ACSA, which runs all the country’s major airports, said profit rose to 2 billion rand ($151.63 million) in the year to the end of March from 1.8 billion rand the previous year.

Domestic passenger numbers rose by 2.2 percent, but international departing passengers grew by 6.1 percent, helping to increase total revenue to 8.6 billion rand.

The firm draws most of its revenue from charging planes for landing and parking, passenger tariffs and renting retail space at its airports.

ACSA Chief Executive Officer Bongani Maseko said the company continued to be resilient, despite sluggish economic growth, and had been able to reduce its debt over the past five years.

Debt, primarily in the form of bond issues, stood at 9 billion rand at the end of the financial year, down from 17 billion rand in 2012, the company said.

ACSA has been paying off expensive debt it took on between 2009 and 2010 to revamp and expand its airports before the 2010 soccer World Cup.

ACSA has often performed better than some of its state-owned peers such as power utility Eskom and airline South African Airways, which are seen as a drain on the government’s purse and have been singled out by ratings agencies as a threat to the country’s investment grade rating.

($1 = 13.1898 rand)