Woolworths says it will not join a protocol to tell the competition regulator when it buys supermarkets, liquor stores and hardware stores, because it would mean more red tape.
The ACCC is trying to streamline the way it assesses small takeovers by Australia's two major supermarket chains to ensure they do not gain too much market power.
Coles has agreed to tell the regulator when it buys up supermarkets, but it will not do the same for hardware or liquor purchases.
Woolworths has held out, saying it will notify the ACCC of any acquisitions at its own discretion.
The company said the new process should apply to all supermarket chains, including low-cost rivals Aldi and Costco.
"Woolworths has notified and cooperated with the ACCC for many years on acquisitions and will continue to do so into the future," the company said in a statement.
Woolworths says it agrees the regulator's evaluation of acquisitions should be streamlined, "however, the process should apply to all industry participants".Â "More than ever, helping retailers to lower the price of goods and services, and not adding more red tape and obstructing the very real competitive forces, is what regulators and all stakeholders should be aiming for," the company said.Â ACCC chairman Rod Sims says it is important to ensure the major supermarket chains do not misuse their substantial market power.
"It's important because the supermarkets in various forms have got high market shares in supermarkets themselves, in liquor and particularly, in the case of Wesfarmers, in hardware," Mr Sims said.
"And they are doing a lot of acquisitions, so we're concerned that if we don't monitor these individual acquisitions their share will grow without us realising it." A spokesman for Coles says the company has worked closely with the ACCC on a trial arrangement.
"We'll assess the impact of the trial and continue discussions with the ACCC regarding any ongoing arrangements," the spokesman said.
Mr Sims says Coles and Woolworths wield a lot of market power.
"What we need to do is make sure that we are enforcing the competition law to make sure that they're not doing acquisitions that lessen competition in a local market, and to make sure that they don't misuse their power," he said.