BP Amoco confirms it has tentatively settled five lawsuits brought a former employee and by four families of ex-employees who had worked at the chemical company’s Naperville, Ill., facility and who had died from a mysteriously contracted malignant brain cancer.

The family of a sixth such victim has yet to settle, although negotiations are ongoing, a company spokeswoman said. She described the settlements only as “fair” and without admitting any company wrongdoing.