WILMINGTON, Del. (AP) _ The Du Pont Co. has temporarily stopped growing high concentrations of the AIDS virus at its Experimental Station near here while investigators try to find out how a federal laboratory worker became infected with the virus, the company says.

But the company has not suspended acquired immune deficiency syndrome research as a result of the incident, Du Pont spokesman Donald Verrico said Friday.

Du Pont has taken a conservative approach and stopped using the high research concentrations of virus until it learns details of the case at the National Institutes of Health in Washington, Verrico said.

The NIH investigation is expected to be completed in about 10 days, he said.

On Sept. 4, federal officials reported that an NIH laboratory worker who had no known risk factors for AIDS, other than working with concentrations of the human immunodeficiency virus, had tested positive for exposure.

The worker has shown no symptoms of AIDS, which breaks down the body's immune system and its ability to fight off disease, they said. Researchers are uncertain what percentage of those exposed to the disease will go on eventually to develop it.