Mr Walsh, on a visit to Ulster University in Belfast, said: "Without question, it will be an advantage."
He would prefer that the UK abolishes Air Passenger Duty (APD).
But, in its absence, he said carriers within his International Airlines Group (IAG) would "certainly look at what is on offer" from Stormont.
Economy Minister Jonathan Bell has promised a decision on an air route development fund by the end of next month.
Potentially, it could be a Â£4m incentive package to help fund important business and tourism connections.
The Northern Ireland Executive could, on its own, scrap all APD, but it would cost it at least Â£55m to repay the Treasury in lost tax revenue.
Mr Walsh - a long-standing critic of APD - said it was "unfair to ask Stormont to make up the gap", adding "the chancellor should pay for it."
He also expressed potential interest in Bombardier's new C-Series aircraft, which has struggled for orders and put the company under huge financial strain.
He said the smaller version - the CS100 - "is possibly an option" for his airlines operating at London City Airport.
"People will watch its introduction into service (later this year)," he said.
"If it can demonstrate it is not just a good aircraft on paper then it will get more interest."

The six girls were taking part in the FIRST Global Challenge competition, which took place across three days and saw 158 nations compete against each other.
They took home a silver medal for courageous achievement, which was awarded to teams "that exhibit a can-do attitude throughout the challenge, even under difficult circumstances, or when things do not go as planned".
According to the New York Times, the team's mentor Alireza Mehraban said: "We are simple people with ideas. We need a chance to make our world better. This is our chance."
A visa is a special permission that you get in your passport which you sometimes need in order to enter or stay in a country for a certain period of time
Their story made the news because, at first, they weren't going to be allowed to go to the competition because of visa problems.
They were told twice that they weren't allowed to enter the country so wouldn't have been able to take part.
However, US President Donald Trump stepped in at the last minute and the girls were able to travel to the US and participate.
The competition - which hopes to inspire young people to want careers in science, technology, engineering, and maths - will take place in Mexico City next year.

Some operations have been cancelled and extra staff drafted in to deal with a surge of patients over the weekend.
The Bristol Royal Infirmary, Southmead Hospital and Weston General hospitals are affected.
More beds are being opened but people are urged not to go to A&E unless they have a "life-threatening" condition.
Instead they are urged to go to minor injury units, chemists and GP surgeries, or to call the NHS on 111.
A black alert, the highest level, means hospital services are unable to cope with demand. The three hospitals were last on black alert earlier this month.
The number of people in hospital for more than two weeks is much higher than usual, said an NHS spokesman.
A surge of patients during last week's cold snap has added to pressure.
The black alert is likely to stay in place for days. Extra ambulance staff are being used to transfer patients into hospital, to prevent ambulances queuing and district nurses are being deployed to hospitals, to help find community beds for patients well enough to leave.
Bristol GP Peter Goyder said an increase in hospital admissions together with "a higher number of very ill patients who need to stay in hospital for longer" had contributed to the situation.
Analysis of the most recent figures suggests hospitals in England are struggling to meet the four-hour target for treating or admitting 95% of patients.
Three hospitals in Cornwall also went on black alert this month, as did two in Somerset.
A Stormont fund to attract new air routes has the backing of Willie Walsh, the boss of British Airways and Aer Lingus.
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A team of girls from Afghanistan has won a special award at an international robotics competition in Washington in the US.
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Hospitals with A&E departments around Bristol are back on black alert for the second time in a month amid "severe pressure" on services.