Employers who make fewer injury claims should pay less, the Accident Compensation Corporation says.
ACC is consulting on proposed increases to levies but they are unlikely to go ahead after its minister Nick Smith said he was unlikely to support them.
The organisation is also consulting on implementing an "experience rating" inthe work account - a policy Dr Smith announced in July.
ACC chairman John Judge said that would see levies for a business based partly on its claims history.
"Experience rating will ensure levies are fairer and will also provide an incentive for businesses to improve their injury prevention and injury management performance," he said.
Dr Smith said the policy would improve safety and under the current system businesses with good workplace safety were carrying the cost of others that were less safe.
The Council of Trade Unions said such ratings schemes encouraged the concealment and down-playing of accidents.
CTU president Helen Kelly said that in Canada an audit last year of Ontario's Workplace Safety and Insurance Board's incentive programme found about 11,000 worker injuries were downplayed or improperly handled over a seven-year period. Injuries included amputations, fractures, dislocations, burns and other injuries that companies reported as resulting in not even one day off work.
Ms Kelly said bosses would pressure workers to lie about how injuries happened, push them back into work too soon and stop reporting near misses.
There were other reports showing ratings were not useful and she accused the Government of wanting to help private insurers, "because private insurers need it in order to rate a customer's risk factor for setting premiums".
The CTU believes the Government has a privatisation agenda but the minister has previously said that is not his intention.
