Coles Group Ltd (ASX: COL) shares are tumbling today.
Shares in the S&P/ASX 200 Index (ASX: XJO) supermarket giant closed yesterday trading for $24.37. In early morning trade on Wednesday, shares are changing hands for $23.07 apiece, down 5.3%.
For some context, the ASX 200 is down 0.3% at this same time.
Here's what's happening.
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Coles shares tumble on ACCC decision
Coles shares look to be catching headwinds today after the Australian Competition and Consumer Commission (ACCC) ruled against the supermarket giant's proposed acquisition of a leasehold interest in Kalgoorlie-Boulder, Western Australia.
In November 2025, Coles notified the ACCC of its intention to acquire the lease for a vacant site to build a new large format supermarket and a Liquorland store.
Having now concluded its Phase 2 assessment of Coles' proposal, the ACCC reported this morning that the new Coles stores would likely "substantially lessen competition" in the retail supply of groceries by supermarkets in Kalgoorlie.
Kalgoorlie currently has four large, full-line supermarkets – a Coles, a Woolworths Group Ltd (ASX: WOW), and two large independent stores.
The ACCC said it's likely that if a Coles new development were to go ahead, this would see "an effective independent full-line competitor, and its assets" likely exit Kalgoorlie. The commission noted this would then result in reduced competition.
What did the ACCC management team say?
Commenting on the decision that's pressuring Coles shares today, ACCC deputy chair Mick Keogh said, "We conducted extensive inquiries and analysis of material provided by Coles and third parties, and assessed the likely competitive effects of the acquisition on competition in the retail supply of groceries in Kalgoorlie."
Keogh added:
Independent supermarkets are an important competitive constraint on the major supermarket chains. They provide consumers with meaningful choice, competition on service, quality and range, and competition on price for some products.
We found that while a new Coles supermarket will offer benefits to some consumers, there is a real prospect that the acquisition would lead to the exit of an effective independent competitor, and its assets leaving the market. New entry would not be timely enough and sufficient to offset the loss of competition likely to result from the acquisition.
Keogh concluded:
Based on our assessment of all of the material before us, we are satisfied that there is a real commercial likelihood that Coles' proposed acquisition would substantially lessen competition in Kalgoorlie in the longer-term, to the overall detriment of consumers.
With today's intraday fall factored in, Coles shares remain up 10.5% over the past year, not including dividends.
