An airline spokesperson confirmed Hawke's Bay would be serviced by the new aircraft.
Mr Luxon said the airline is proud of its commitment to operating both a world-leading turboprop fleet and a comprehensive regional network.
"The extra four 68-seat ATR72-600 we are adding to our fleet will enable us to operate up to an additional 600,000 seats into the New Zealand regional market annually," he said.
"This latest investment will further allow us to maintain our low fare price and high frequency leadership."
Mr Luxon said when the new planes arrived, Air New Zealand would be operating 29 ATR aircraft, the third-largest ATR fleet in the world.
In 2012, the airline announced it would add to its ATR fleet with an investment in 14 ATR72-600 aircraft - seven have been delivered with the remaining seven due to join the fleet by mid-2016.
Air New Zealand also operates 10 19-seat Beech 1900D and 23 50-seat Bombardier Q300 aircraft types.