US retailer Costco Wholesale has said it is considering making a move into the Australian market, but is still at least 12 months away from opening a store there.

"We've had someone in the country for two years researching the opportunity to come to Australia," vice president of finance and investor relations Bob Nelson told Dow Jones Newswires.

The company, which operates warehouse-style stores, said it had not yet acquired any store sites in Australia and is still doing its homework as far as the country is concerned.

"If it happens, it won't be in the next year… It could be a year, it could be five years," Nelson was quoted as saying.