Major media companies have yet to respond to the possibility that bioterrorism caused Friday's death of an American Media Inc. photojournalist, but The New York Times, Chicago Tribune and other media outlets say they already have tightened security since Sept. 11.

     Bob Stevens, a part-time photo assistant at the supermarket tabloid the Sun, died Friday of an inhaled form of anthrax, and doctors found the anthrax bacterium in two of his co-workers at Boca Raton-based supermarket tabloid publisher American Media Inc.

     Media companies boosted security after last month's terrorist attacks, and they might be forced to further scrutinize packages and potential hires, security experts say.

     The Chicago Tribune, for instance, always X-rays packages that arrive by mail, but it allowed courier deliveries to enter its downtown headquarters unchecked. After Sept. 11, the newspaper required couriers to enter through a special door and X-rayed their packages, too, Tribune spokesman Gary Weitman said.

     Weitman declined to say how much the extra precautions cost or whether security guards have found any weapons as a result. Tribune Co. also owns the Fort Lauderdale Sun-Sentinel, the Los Angeles Times, Newsday and other newspapers and TV stations.

     The Sun-Sentinel on Monday began requiring employees to show ID badges to enter its offices not because of the anthrax outbreak but as a response to the terrorist attacks in New York and Washington, spokesman Kevin Courtney said.

     "We've been increasing our security ever since Sept. 11," Courtney said, but he declined to offer details.

     The New York Times Co., which owns The New York Times and Boston Globe, also has boosted security in the past month, a spokeswoman said, although she declined to offer details. The Miami Herald likewise has increased security since Sept. 11, but does not discuss those measures, an official said.

     The Palm Beach Post also began requiring employees to wear ID badges this week. The Post doesn't X-ray mail, but it might start to do so as a result of a security audit the paper is conducting, Publisher Tom Giuffrida said. The Post is considering other measures such as increasing its security staff.

     "There's a fine line between becoming a fortress and being a place of business where people come and go, and we're trying to walk that fine line," Giuffrida said.

     X-raying packages is a good start, but even that precaution has its limits, said Fred Rustmann, a former CIA agent and chief executive of West Palm Beach corporate intelligence firm CTC International.

     "X-rays will pick out guns and knives and bombs, but I don't know that it would do anything with anthrax," Rustmann said.

     An X-ray might reveal a container, for example, but it wouldn't show the bacterium.

     Corporate security experts should be especially vigilant about suspicious packages, said Bill Gist, president of the Palladium Group, a West Palm Beach security firm. If a package looks strange, don't hesitate to call in experts in bombs or biological weapons, Gist said. "Your average corporate security person doesn't have any expertise in biological agents," Gist said.

     Palladium counts American Media among its clients, but Gist declined to comment on the investigation there.

     In general, security experts said, companies should make sure that security cameras cover their entire properties, and no vehicles should be allowed within 50 feet of a building. Air intakes should be secured to prevent biological attacks.

     Boosting security is expensive and intrusive, but last week's anthrax death underscores the need for increased vigilance, he said.

     "The outbreak is very strange to me," Rustmann said. "As an intelligence officer, I don't believe in coincidences."