International Airlines Group chief executive Willie Walsh has reiterated the company's commitment to the Belfast City Airport to London Heathrow route.
Mr Walsh said its airline British Airways has outperformed expectations and stood up to competition from Aer Lingus on the shuttle service since its takeover of BMI last year.
"Belfast is a very important market for us, it's doing very well," he said. "We're facing more competition out of City Airport (George Best Belfast City Airport) now that Aer Lingus have moved in there, but we're delighted to be back in the market in the same way as we're delighted to be back in the Dublin market."
Aer Lingus moved its Belfast base from Belfast International in autumn 2012, going head-to-head with British Airways on the Heathrow route.
Mr Walsh said: "The market there is good and has performed better then we thought so we're in it for the long-term without question.
"Aer Lingus is competition but I think people thought that as soon as they announced the move to Belfast City we were going to leave, but we've demonstrated that wasn't the case and we're not doing that. We're certainly pleased with the way the route is performing for us."
Mr Walsh was speaking en route to central China on the airline's inaugural flight to Chengdu.
It will fly direct from London Heathrow three times a week and, speaking to Chinese media, Mr Walsh said the airline could increase that to five weekly flights.
The new route sees British Airways target the growing affluence and economic prosperity of China's so-called second tier cities.
"Trade between the UK and China continues to grow and will be worth $100bn (£62bn) by 2015," Mr Walsh said.
"I'm sure that the launch of this new route, in addition to British Airways' existing flights to Beijing and Shanghai, will be a key factor in developing business links between our two countries."
Tourism is also a key driver behind the new route. Last year, 179,000 Chinese visitors travelled to the UK, contributing £300m to the economy. In the first quarter of 2012 that's already up 30%.