Preliminary results from research funded by the cellular telephone industry suggests there may be a correlation between cell phone use and cancer, according to the director of the program. The study found possible connections both in biological tests and statistical analyses of cell phone users.

The findings are at odds with many previous studies, which found no such link. But at a time when use of cell phones is exploding -- roughly 70 million were in use in the United States as of December -- the findings will enter the debate over whether the phones' radio emissions can be harmful.

The data, while "important," only suggest that more research is necessary, said George Carlo, chairman of the industry-funded Wireless Technology Research group. "We're now in a gray area that we've never been in before with this. When we're in a gray area, the best thing to do is let the public know about the findings so that they can make their own judgment," he said.

An official of the Food and Drug Administration, which regulates the safety of cell phones, agreed. "These results seem to have been done well -- the question now is, `Okay, we've got a result. What do we do with it? How do we follow through?' " said Elizabeth D. Jacobson, deputy director of science at the FDA's Center for Devices and Radiological Health.

Jacobson and other FDA officials have been briefed on the WTR results; Jacobson said that if a clear health threat emerged from the studies, she and the agency would move quickly to address the problem.

In this case, however, Jacobson said the results make a strong case for conducting more research but not for taking regulatory action at this time: "We didn't see what we thought were public health problems," she said.

The Cellular Telecommunications Industry Association would not comment on the record about the new research, but has called for further studies to be conducted under the direction of the federal government and international health agencies.

Early-model cell phones were mounted in cars, with the transmission antenna and its radio waves far away from the user. But in the 1990s, as handsets held directly against the ear became common, some people began to worry that the radiation might be harmful.

The debate broke into the open when a Florida man went on the "Larry King Live" program in 1993 and alleged that a cellular telephone caused his wife's brain cancer. Regulators and scientists subsequently have struggled to shed light on whether the phones have any health effects.

Radio waves are part of the electromagnetic spectrum, which includes kinds of radiation that are clearly carcinogenic, such as X-rays, and others that are harmless, such as visible light. Also, cell phone users -- who tend to be more prosperous than the general population -- might share other risk factors for cancer that have not yet been subjected to scrutiny.

The industry formed WTR in 1993 to conduct a $25 million series of independent studies and hired Carlo to coordinate the effort.

The new findings are the first major disclosure by the group of the results of its research. These and all WTR-sponsored findings to date will be presented at a colloquium in Long Beach, Calif., on June 19 and 20.

One line of WTR research involved the examination of cells from various animals that had been subjected to radiation from four types of cell phones. The research, conducted at Stanford University and Integrated Laboratory Systems in Research Triangle Park, N.C., put the cells through 46 tests for cancer-inducing genetic damage. Most produced the usual result in cell phone research: no sign of cancer-causing damage.

But one battery of eight tests, known as a "micronucleus assay," on human blood cells did indicate chromosomal damage.

"At this point there is very little you can make of" this finding, said Graham Hook, a program director at Integrated Laboratory Systems. "It's difficult to interpret," and might be attributable to other factors. The real role of such tests, he said, "is to tell you what needs to be further tested."

Some scientists who had been briefed on the results by Carlo said they would reserve judgment until they could see all of the data after it had been through the peer-review process.

"It's interesting, but not worthy of too much attention until it gets published," said W. Gregory Lotz, a researcher at the National Institute of Occupational Safety and Health.

Previous studies that indicated a cancer risk have not been borne out. In the mid-1990s, researchers Henry Lai and N.P. Singh at the University of Washington, Seattle, using a test known as the "comet assay," found DNA breaks in cells exposed to wireless phone radiation. Subsequent attempts by Joseph Roti Roti of Washington University in St. Louis to duplicate the work were unsuccessful, an indication that the first work might have been flawed.

"The fairly simple bottom line is in the work that I've done, I've found nothing that would alarm me, or alert me to a possible hazardous health effect," Roti Roti said in an interview. "To me, the biggest hazard with the cell phone is not paying attention to driving your car when you're using one."

Other lines of research that WTR has pursued are based in epidemiology -- they look for patterns of disease in larger populations of cell phone users.

One WTR-sponsored epidemiology study by Joshua Muscat of the American Health Foundation showed a near tripling of a statistically significant risk of a rare kind of tumor called a neurocytoma among cell phone users, compared with people who do not use cell phones. Neurocytomas grow from the periphery of the brain inward. The result of that study, however, is undercut by the fact that the data did not show that the risk of neurocytoma rose with the amount of cell phone use, which researchers would have expected to find. In fact, greater exposure was associated with lower risk.

Another epidemiological study, also not published yet, found that right-handed people who used cell phones and had brain tumors tended to have them on the right side of the head -- a result that could show a link to radiation from the phones. However, no such correlation appeared in left-handed cancer patients.

Other major scientific exploration of a possible link between cell phones and cancer is being carried out at the National Cancer Institute and the International Agency for Research on Cancer in Europe.

Carlo, who uses a cellular phone with a plug-in earpiece that allows him to talk without holding the device to his head, said he chose to issue the results before publication so that government and industry could take the next step in research. "What we don't want to do two, three, four years from now is to say, `God -- this was the tip of the iceberg, and we didn't see it!' "