CHICAGO (AP) _ Sara Lee Corp. announced Tuesday it is recalling hot dogs and other packaged meats as a precaution after an outbreak of food poisoning sickened more than 35 people in nine states, killing four.

Health officials said the outbreak was caused by the listeria bacterium. The U.S. Centers for Disease Control and Prevention was testing Sara Lee's Bil Mar Foods division in Zeeland, Mich., to see if meat produced there was the source.

``The safety of everyone who eats our products is our No. 1 priority, and therefore we are voluntarily taking this precautionary measure,'' George Chivari, president of Bil Mar Foods, said of the recall.

Sara Lee spokeswoman Theresa Herlevsen declined to say how many packages were involved in the recall, but the company estimates recall costs at $50 million to $70 million.

Healthy people usually can fight off listeria with no more than flu-like symptoms. But the bacterium can kill, causing meningitis or blood infection. Most at risk are pregnant women, the elderly and people with weak immune systems.

Cases are under investigation in Ohio, New York, Tennessee, Massachusetts, Michigan, West Virginia, Connecticut, Oregon and Vermont.

Genetic fingerprinting of the bacterium helped health officials link the cases, and they suspect hot dogs and cold cuts because those are foods the patients have in common.

The products affected by the recall are coded EST P261 or EST 6911 and include the national Ball Park, Grillmaster and Hygrade brands, distributed throughout the United States. Also affected are the regional Bil Mar, Bryan Bunsize and Bryan 3-pound Club Pack hot dogs, Mr. Turkey, Sara Lee Deli Meat and Sara Lee Home Roast brands.

Consumers can return the packages to the place of purchase for a full refund.