Flying from Belfast to New York will be cheaper from November after the British government announced a cut in local air passenger duty.
Under plans revealed on Tuesday, the tax on a direct long-haul flight from Belfast will fall to the cost of the short-haul rate of £12 for economy class and £24 for business and first class.
The tax currently adds £60 to an economy ticket and £120 to a business ticket.
The high cost of the tax had threatened to kill off the direct flight from Belfast to New York, as passengers were increasingly choosing to cross the border into Ireland and take the equivalent service from Dublin where the extra charge is just £2.60.
George Osborne said the move was needed to help stimulate the Northern Ireland economy.
“The government has taken proactive measures to protect the only direct long-haul service operating from Northern Ireland and with it the jobs of those who serve the Belfast route," he said.
"Northern Ireland faces a unique challenge in attracting traffic – including very valuable business customers – into its airports.
"By announcing this immediate cut and our intention to devolve aspects of APD, the UK Government is renewing its commitment to stimulating and rebalancing the Northern Ireland economy.”
The government is also due to transfer some powers over setting of APD to the Northern Ireland Assembly.