"We are still continuing our search at this time", she said. High winds and rough seas made the search hard.
'Pacific Dawn had searched through the night and into the morning after first light without success.
"The hard decision to suspend the search was made only after expert advice that survival after this length of time in hard sea conditions and after a full night at sea was not considered possible", Carnival Australia spokesman David Jones said on Friday.
P&O Cruises spokesman David Jones had earlier flagged that the search would continue until maritime authorities agreed to call it off, but admitted hopes were fading.
A crew member raised the alarm around 4pm on Thursday, and the "man overboard" incident response was activated straight away, with the ship turning around and retracing its course.
Passengers told News Corp the woman had gone outside to vomit and was thrown overboard when a wave hit the ship, with one saying her husband saw the whole thing.
He said little information was being given to passengers about the situation other than they were searching for the missing woman.
"With the deepest sadness, P&O Cruises has confirmed the suspension of Pacific Dawn's search for the female guest who was seen to go overboard from the ship late yesterday afternoon approximately 150 nautical miles from New Caledonia", the company said.
"Our thoughts and prayers are with the guest's family at this distressing time".
Queensland Police officers are due to meet the ship when it returns to Brisbane on Sunday, at around 11 a.m. It had left Brisbane last Saturday on a seven-night "Pacific Island Hopper" cruise.
A passenger onboard Pacific Dawn says its parent cruise ship company can not be faulted for the way it has handled the tragedy of a woman falling overboard.