(Corrects with annual USDA slaughter figures paragraph nine)
* Spread of deadly pig virus has tightened U.S. hog supply
* An estimated 4 mln-5 mln pigs have died of virus in past 10 months
* Disease does not affect humans, not a food safety risk
* More processors likely to curtail slaughter operations in future
By Meredith Davis and Christine Stebbins
March 14 (Reuters) - Smithfield Foods Inc, the world's largest pork processor, suspended hog slaughter at its Tar Heel, North Carolina, plant on Friday because of the spread of the deadly Porcine Epidemic Diarrhea virus (PEDv) which has tightened hog supplies, industry sources said.
The Tar Heel plant, the company's largest pork processing facility, reduced its slaughter schedule this week to four days from five days, said the sources, who have knowledge of the plant's operations and hog purchases. They requested anonymity because of the sensitivity of the issue.
While it is not slaughtering hogs on Friday, the plant is processing meat from this week's kill, the persons said.
Smithfield, acquired last year by China's Shuanghui International, said it does not comment on daily operations, minor disruptions, and openings or closings of processing plants.
Friday's move follows days of market talk about U.S. pork processors cutting back working days because of reduced supplies, a measure that reflects the growing damage caused the virus.
It is not clear how long the company will adhere to the shortened slaughter schedule. Smithfield may also reduce operations at its plant in Clinton, North Carolina, the sources said.
The Tar Heel plant is the largest pork processing plant in the United States, with an estimated slaughter capacity of 30,000 to 34,000 hogs a day.
Smithfield's decision to reduce the kill schedule in response to the hog virus is expected to be repeated by other companies in the weeks ahead as U.S. pork processors struggle to source hogs, analysts said.
The United States, the world's largest pork exporter, slaughtered some 112 million hogs in 2013, according to the U.S. Department of Agriculture.
The pig virus has spread across the U.S. Hog Belt with swine specialists estimating that at least 4 million to 5 million hogs have died of PEDv since it was identified in the United States in May 2013.
PEDv does not affect humans and is not a food safety risk.
The tight supply of hogs was reflected in the U.S. government's weekly slaughter estimates on Friday. The U.S. Department of Agriculture estimated Friday's hog slaughter at 360,000 head, down 51,000 head from a week ago.
The USDA estimated hog slaughter so far this year down 3.5 percent from the same period a year ago.
"I think that kind of operating approach, cutting one day a week, is possibly coming to some Midwest plants in May," said Steve Meyer, livestock economist at Paragon Economics.
Plants owned by Hormel Foods Corp, JBS Swift , and Triumph Foods are among Midwestern facilities that plan either to trim daily operations by a couple of hours, eliminate overtime or suspend Saturday slaughter, according to sources in the cash hog market. (Reporting by Meredith Davis and Christine Stebbins in Chicago; editing by Matthew Lewis)