CHICAGO, March 27 (Reuters) - U.S. beef sales to China

have taken a dive, U.S. government data showed on Thursday,

after Beijing allowed the expiration of registrations that had

permitted exports from hundreds of American meat facilities.

A tit-for-tat tariff dispute has also raised duties on U.S.

meat and other goods shipped to China, making the products less

attractive to Chinese buyers. The spat adds new strains to

relations between the countries that had already reached

historic lows in recent years.

China has not renewed export registrations for U.S. beef

facilities that expired on March 16, though it updated

registrations for pork and poultry plants, according to traders

and the U.S. Meat Export Federation trade group.

As a result, U.S. exporters and Chinese buyers are reluctant

to strike deals for American beef produced after that date due

to uncertainty about whether it will be cleared for delivery,

federation spokesperson Joe Schuele said.

"Nobody wants to put product at risk," he said.

U.S. beef export sales to China in the week ended on March

20 were nearly nothing at 54 metric tons, according to U.S.

Department of Agriculture data. Sales were also low, at 192

metric tons, in the previous week, as traders said uncertainty

about the export registrations cooled business before they

lapsed.

Previously, weekly sales were near or above 2,000 metric

tons for four consecutive weeks from mid-February through early

March, USDA data show.

The decline in Chinese demand is a blow to U.S. meatpackers

such as Tyson Foods ( TSN ) that are already paying high prices

for cattle due to tight supplies.

"The packers are all concerned because obviously it's a big

market for U.S. beef," said Altin Kalo, agricultural economist

for Steiner Consulting Group. "It's been two weeks now where

we're basically at zero."

The USDA and the Meat Institute, an industry group

representing U.S. meat processors, had no immediate comment.

China's Commerce Ministry launched an investigation into

surging beef imports late last year, as the world's largest meat

consumer grappled with an oversupplied market that hammered

domestic beef prices. A hearing on the matter is slated for next

week.