New Zealand is bargaining to buy 11 naval helicopters the Australian military considered too unsafe to fly.

The Super Seasprite SH-2G(I) would replace the existing five earlier model SH-2G choppers which are facing maintenance issues.

No prices have been disclosed but when the Australians signed a deal for the SH-2G(I) they were worth, in 2008, a total of $1.4 billion.

Aviation media is speculating New Zealand could get the package for $230 million. Only two other military forces, Egypt and Poland, now flies them.

US manufacturers Kaman Corporation said in a statement earlier this week they had received authorisation from the US State Department to negotiate the sale.

It would include 11 helicopters, a full motion flight simulator, training aids, spares inventory, publications and the introduction into service and through-life support of the aircraft.

Kaman say the SH-2G(I) is the latest version of the multi-mission maritime helicopter.

"These helicopters would significantly enhance New Zealand's vertical lift capabilities with exceptional performance and low operating costs," Kaman say.

"Negotiations regarding a potential programme between the New Zealand Government and Kaman are in process and are confidential.

"No investment decisions have been made by New Zealand at this time and Kaman continues to work with other potential customers on the sale of the aircraft."

Australia ordered the helicopters in 1997 but the project was delayed when modifications ordered by Australia failed to meet performance targets or were too difficult to implement in the refurbished air frames.

Then-Australian Defence Minister Joel Fitzgibbon said he had cancelled the contract on safety grounds.

"The airworthiness and crashworthiness of the aircraft was not up to 21st-century standards and it was pretty clear the capability was not likely to be delivered in full."

Last year, a New Zealand Defence Department study said the Navy's $350 million five helicopters were un-flyable much of their time after ending up as the only country flying their model, threatening a maintenance struggle to cope with worsening corrosion and vibration damage.

Earlier this month Defence Minister Jonathan Coleman told Aerospace Daily & Defense Report New Zealand had received an unsolicited offer from Kaman.

"We're not considering any other types of helicopters at this stage," Coleman told Aerospace.

"We are very familiar with the Seasprites and we are facing a tight budget situation."

If New Zealand were to switch to another type, it would have to retrain its pilots and invest in new training equipment.

He said the issues that worried the Australians had been corrected.

"We're investigating further to see if the helicopters will meet our needs and see if the aircraft would achieve airworthiness certificates in New Zealand," he said.

- © Fairfax NZ News