US poultry giant Pilgrim's Pride has launched the largest US meat recall in history and halted production at a Pennsylvania plant because of possible contamination with listeria.

Pilgrim's Pride - the second biggest US poultry producer - said in a statement it was recalling 27.4 million pounds (12.4 million kg) of fresh and frozen ready-to-eat turkey and chicken products under the Wampler brand.

The company said the recall occurred after environmental tests at its Franconia, Pennsylvania, plant found a strain of listeria similar to the one identified in an outbreak in the US Northeast that has caused at least 23 deaths and 120 illnesses.

"A strain with similar characteristics to the (Northeast) outbreak was found on the plant's floor drain, but it was never in contact with food," said Richard Cogdill, the company's chief financial officer.

Cogdill said the recall was a "precautionary step" and no illnesses have been linked to meat produced by the Pittsburgh, Texas-based company.

"We have no reason to believe our products are the cause of this," he added.

The company said it voluntarily closed the meat processing plant about 25 miles north of Philadelphia.

The recalled deli meat products were produced between 1 May and 11 October and distributed nationwide. All products bear the establishment code "P-1351" inside the USDA mark of inspection.

Pilgrim's Pride last week pulled 295,000 pounds (133,812 kgs) of turkey and chicken products from the market due to listeria concerns.

Eating food contaminated with Listeria monocytogenes can cause listeriosis, leading to miscarriages and stillbirths, as well as infections in those with weak immune systems.

The USDA and the Centers for Disease Control and Prevention have been unable to pinpoint the source of the listeria outbreak in Pennsylvania, New York, New Jersey, Delaware, Maryland, Connecticut, Michigan and Massachusetts. But the CDC has suspected turkey deli meat as one likely source.

The company said it hoped to reopen its meat processing plant by Tuesday."We closed the plant and we are completely resanitising the equipment," Cogdill said.

Steve Cohen, spokesman for the USDA's Food Safety and Inspection Service, said the department must first certify the plant meets federal food safety standards before it can be reopened.

About 2,500 cases of listeriosis occur each year in the United States. Listeria can be destroyed by cooking meat to a temperature of at least 160 degrees Fahrenheit (71 C).

In the previous largest US meat recall, Hudson Foods recalled 25 million pounds of hamburger in 1997 after 15 people in Colorado fell ill. Hudson was purchased by poultry giant Tyson Foods one year later.