A proposal to put an iconic Coromandel beach into public ownership has been withdrawn, but a new estimate that halves the land's value has given the Green Party hope a deal could still be done.

The proposal sought for the Government to pay half the estimated $20 million value of New Chums beach to protect it from development.

The landowner would gift the same amount into a trust to protect the coastline and create a public reserve next to the beach.

Prime Minister John Key last year asked the Department of Conservation to look into the proposal, which has since reported back to Government. A decision had been due this month.

But the owners have since withdrawn the proposal, Radio New Zealand reported today.

The Environmental Defence Society, which had been working with the owners to put the land into public ownership, said it feared the Government would reject the offer.

"We just need to hit the pause button and leave it for a while because of that terrible situation in Christchurch occupying everybody's attention, and quite rightly so," chairman Gary Taylor told Radio New Zealand.

"We've indicated to the Prime Minister and the Minister of Conservation that we'll be coming back with a new proposal."

Conservation Minister Kate Wilkinson said she was surprised at the late withdrawal of the proposal, but she was prepared to look at any new proposal whenever it was put forward.

The withdrawal comes as a new Government valuation puts the value of the land at $10 million, half of what it was initially estimated to be worth.

Green Party MP Catherine Delahunty, who has for years been campaigning on environmental issues in the Coromandel, said the new valuation would make collaborative ownership more achievable.

"If the developers are still willing to put up half the money, the Government and community now only need to come up with $5 million," she said.

"Buying New Chums back at a fair price is a win-win outcome for both the developers and the country, and I am hopeful that this can still happen."

Ms Delahunty said the Christchurch earthquake was obviously a priority for Government spending.

"In light of this, it is reasonable for the developers to withdraw and revise their offer, so long as they don't re-draw boundaries or compromise wilderness values," she said.

"Any new proposal needs to be based on the Government valuation of the land."

More than 1300 submissions were opposed to development of the 280ha site, where 20 houses had been planned.