ROME (AP) _ With mamas calling sons, sons calling girlfriends, and most everyone calling someone to discuss what's for dinner, Italians have found one more thing to be passionate about: cellular phones.

But Italy's mania for mobiles _ the number of cell phones in Italy surpassed the number of conventional phones this summer _ means a sharp rise in the number of transmitters needed for the high-tech talk to flow.

That's where Italians, from Sicily to the Alps, are drawing the line. Citizens are taking on the cellular phone industry, fighting the installation of high-rise transmitters in their communities.

Cell phone networks are anxious.

``We've had enormous difficulty in realizing our plan,'' says Pietro Porzio Giusto, vice president at TIM, Italy's largest mobile phone operator.

``There will be ever more problems at peak time'' if citizens continue to balk, he said. ``They will find the lines busy.''

That doesn't seem to bother Federico Polidoro, whose eight-story building in Rome is draped with a banner to protest the installation of a transmitter.

``We've blocked the arrival of cranes four times,'' he said. ``We found out by accident in December when we saw the workers who were trying to install the transmitter.''

Polidoro, a 35-year-old statistician who lives on the seventh floor, said he and fellow tenants collected 1,500 signatures of protest from the neighborhood, where five towers have already gone up.

Consumer activists say one tactic of the cell phone operators is to scout for sites where the landlord is a business or a religious institution and to avoid condominiums, where the occupants are owners with a say.

Those willing to sign on for a transmitter can practically name their price these days. The result, according to TIM's Porzio Giusto, is that costs have doubled.

``We've paid exaggerated prices,'' Giusto said.

About 200-300 new towers are needed each month to keep up with the increased cell phone use, phone company officials say. This summer, the number of cell phones in Italy, a nation of 57 million people, hit 25 million.

Polidoro concedes that there is a contradiction somewhere in a country that embraces cell phone chatter but balks at the transmitters.

``But using a cell phone is an individual choice. A transmitter over your head or next to you without your choice is another thing,'' he said.

Like his colleagues at the other two mobile phone operators, TIM and Omnitel, Roberto Piermarini of Wind contends local politicians whipped up anti-transmitter sentiment. He noted the protests really took off last spring, before several rounds of mayoral and other local elections throughout Italy.

``We react by explaining that their fear is unjustified,'' said Antonio Bernardi, Omnitel's legal affairs director.

The phone companies say no conclusive evidence has turned up to link exposure to electromagnetic waves emitted by the towers to health problems or illnesses.

``They say nothing is proven, but this goes on 24 hours a day,'' said Alessandro Maggini, pointing from his dining room window behind Rome's Trastevere train station to a 25-foot high Omnitel transmitter 15 yards away.

``It's not like a TV set you can turn off,'' he said.

Under a 1998 law, Italy has far more stringent standards for the intensity of electromagnetic fields generated by transmitters than other European Union countries have.

``The perception of risk is strongly distorted,'' said Angelo Lozito, a physicist for Legambiente, an environmental protection group. ``They don't know that in the house, the clock radio, the refrigerator, generates far more (electromagnetic) pollution.''