US BEEF exports are muscling in on some of Australia's key markets.

It is part of the reason why US beef exports are predicted to break records when final calculations for 2011 are completed.

Figures collected by the United States Department of Agriculture show US beef exports are on track to pass $4.8 billion last year.

And while Canada and Mexico are the biggest customers for US beef, it is also making inroads into Japan and Korea.

From January to November last year, the US exported 129,552 tonnes of beef to Japan, a lift of 33 per cent compared with the same period a year earlier.

There were also increased sales to Korea, up 34 per cent to 123,456 tonnes for the first 11 months of the year.

Analysts said the weak US dollar helped make the country's beef more competitive.

Meat and Livestock Australia chief economist Tim McRae said Australian producers "should be worried" about the increasing US share in traditional Australian markets.

"It is partly in response to the very weak US dollar, which has made the US product more price-competitive," Mr McRae said.

"It's certainly a big caution sign for Australian producers, but it is not totally unexpected either. Ever since the US was locked out of markets after its outbreak of BSE, we have been waiting for them to come back into the markets, and they are starting to now."

But Mr McRae said it was important to put the rises into perspective.

"The US is still only sending about one-third of the product it used to send to Japan and about half the amount to Korea," he said.

What was of greater concern was the switching of customer preferences by Japanese consumers away from high-end restaurants serving grain-fed beef to more manufacturing beef.

This was seen in the record amount of Australian frozen beef taken by Japan, as opposed to the lowest amount of chilled, higher-quality beef since 1994.

Mr McRae said while Japanese consumers remained so price-conscious, Australia would have a fight on its hands competing with US product, which had a price advantage.

"We still have the advantage of a clean, green product and that goes a long way," Mr McRae said. "Japan is our largest market and will remain so for many years, but given expanding markets in other countries, we have found other customers who want significant amounts of our product."