The chief executive of International Airlines Group, which includes British Airways and Iberia, completed a deal to buy Irish carrier Aer Lingus in August and has set his sights on adding more airlines to the growing company.

“We’d like to collect a few more. There is great ambition within IAG, I think we’ve been really heartened by the progress we’ve made,” he told the audience at the UK Aviation Conference 2015.

The Aer Lingus deal follows others for BMI in 2012 and Vueling in 2013.

“If the right opportunity presents itself then we won’t be shy about progressing further but we’re not actively pursuing anything at the moment.”

Meanwhile, Walsh revealed mixed feelings towards the Airports Commission’s final report released in the summer.

He said the document produced by Sir Howard Davies was “excellent” but remains concerned about the price the industry will be forced to pay for expansion at Heathrow.

“I have concerns about the level of cost associated with the favoured recommendation.

He added: “We believe it’s outrageous the levels of capital expenditure that have been identified and can’t see how its justified and certainly would not be prepared to pay or to support the development…”

Walsh also said that the government could decide to back development at Gatwick because it is the easier sell to the public.

“I think the economic argument is very, very much in favour of Heathrow, but the political argument is probably more in favour of Gatwick. The issues around Heathrow are well know and I don’t think we have brave politicians.”