New Zealand's commerce watchdog has cleared an Australian supermarket chain of using anti- competitive and intimidating behavior against suppliers in allegations that were first raised in the New Zealand Parliament earlier this year.

The Commerce Commission said Thursday that the allegations against Progressive Enterprises Ltd., which operates the Countdown supermarket chain, were serious, but it did not believe Progressive had breached any trading laws.

"The supermarket industry is important in New Zealand. It has an impact on all New Zealanders and it is vital that it operates in a competitive way," chief executive of the commission Brent Alderton said in a statement.

The commission had received almost 90 complaints focusing on allegations that the supermarket chain used its market dominance to illegally mislead and coerce suppliers, but the evidence failed to show any breach of the law.

Progressive, which controls one of only two main supermarket chains in New Zealand, welcomed the news, saying it negotiated in a competitive environment, but always in good faith and in a fair and transparent manner.

Managing director Dave Chambers issued a statement in which he also attacked the way in which the allegations first surfaced.

"We hope some lessons can be learned about the damage false allegations made under Parliamentary privilege can cause. It's not how any New Zealander wants to operate and our door is always open for anyone to discuss issues directly with us," he said.

However, the main opposition Labour Party said the investigation had demonstrated the need for a mandatory code of conduct for supermarkets to ensure New Zealand suppliers were not affected by anti-competitive behavior.

"Even though the Commerce Commission found no technical breaches of the law through some of Countdown's business practices when dealing with suppliers, 90 complaints would indicate there are serious issues which need to be dealt with," Labour commerce spokesperson Clayton Cosgrove said in a statement.

The commission announced the investigation in February during a trans-Tasman spat over claims that New Zealand suppliers were being excluded from Australian supermarket shelves and escalated into a movement to boycott Countdown stores.

The allegations were voiced in Parliament by then Labour Party economic development spokesperson Shane Jones, who said New Zealand suppliers were fearful of going public lest Progressive blacklisted them.

The commission was forced to offer complainants confidentiality if they gave evidence.

Anger towards the chain started with reports that Australia's Woolworths, the parent of Progressive, and Coles groups, the two main supermarket chain owners in Australia, were refusing to stock New Zealand-made products as part of a "Buy Australian" campaign.