New Zealand and Australia are playing down the chances of a unified Australasian market for carbon emissions, saying it would be difficult to harmonise their schemes for cutting emissions.
The Australian government is planning to start charging for emissions through a carbon-trading scheme from 2011.
New Zealand is reviewing its emissions-trading laws and is expected to announce a watered-down scheme by the end of next year.
New Zealand Climate Change Minister Nick Smith says issues of price caps and international tradeability of units would need to be resolved to bring the schemes closer.
The New Zealand Government expects a report from a parliamentary select committee on its scheme early next week and would study that before making any commitments on the scheme's future, Dr Smith told Reuters.
Australia's scheme aims to cut emissions by 5% to 25% over the next decade, with the higher target dependent on a matching agreement out of global climate talks in Copenhagen in December.
The Australian scheme will be voted on again in November, with a second rejection providing Prime Minister Kevin Rudd with a constitutional trigger for possible early elections.