The search continued throughout the night and into the early hours of the morning with rough conditions and large swell making the operation hard. A spokeswoman said doctors believed she would not have survived past 5am local time in the conditions.
"As a result, we have now made the extremely hard decision to continue our journey towards Brisbane". P&O Cruises said it could not confirm any details.
AMSA had been liaising with New Caledonia search-and-rescue authorities and the cruise ship, with a call going out for nearby vessels to help search.
'We are still in the area of the incident, and the weather conditions with the swell three to four metres high, as you can see outside.the strong wind made our search extremely challenging'.
"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", said a P&O Cruises spokesman.
'I know I speak on behalf of all of you when I say our thoughts and prayers are with the family'.
Queensland police said they would meet the Pacific Dawn when it docked in Brisbane on Sunday, to investigate the incident.
The had ship departed from Brisbane on Saturday.
Passengers said the woman's husband saw her fall and went into shock.
"Guests now onboard Pacific Dawn have been advised of a likely late arrival and guests due to embark on the ship's next cruise will be updated on boarding arrangements".
The ship was about 300 km west of New Caledonia, bound for Brisbane, but made the immediate decision to turn around and search for the woman, P&O Cruises said.
"There is nothing to suggest anything of this kind", P&O said in a statement.
Intital investigations indicated that the woman went overboard 150 nautical miles - nearly 300 kilometres - from New Caledonia, the Queensland Police said in a statement.