Costco the next threat to Coles & Woolies

US retailer Costco has gained a 1.2 per cent share of the local supermarket industry within a short space of time and only with seven stores.

US discount retailer Costco has captured a 1.2 per cent slice of Australia's $88 billion supermarket industry despite only owning a handful of stores across the country.

IT sounds inconsequential against German discounter Aldi's 8.1 per cent share, and Coles and Woolworths' combined 70 per cent share, but fill in the details and the Costco threat becomes more obvious, an IBISWorld report says.