Regional Express will start Monday-Friday daily return flights to Orange from Sydney from July 6.
The airline announced it would increase the number of flights to Orange and other cities in response to its rival QantasLink increasing flights.
However, QantasLink has not yet confirmed when it will begin flights to Orange.
It announced changes last week but did not include Orange in the announcement.
Rex will now have a flight leave Sydney at 7.50am Monday-Friday arriving in Orange at 8.40am.
We are still seeing a 90 per cent drop in passenger numbers.Neville Howell, Regional Express
It will leave Orange at 9.10am and reach Sydney at 10am.
There will also be an afternoon return flight from Sydney to Orange on Mondays, Wednesdays and Fridays.
Rex chief operating officer Neville Howell said the move had been forced on them by the need to compete.
"It is with great reluctance that we are adding so much additional flying so soon that doesn't match demand," he said.
"We are still seeing a 90 per cent drop in passenger numbers and we would normally gradually increase our flying schedule in tandem with the growth in passenger numbers so as to minimise losses.
"QantasLink's aggressive new published schedule for July, announced with great fanfare compels us to match this move so as not to be squeezed out of the market.
"The outcome may result in both carriers doubling or tripling their losses on these routes given the expected load factors of 30 per cent or less," Mr Howell said.
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