But from the start, the arrival of the profit-making company encountered resistance that sometimes included protests, threats and vandalism.

Officials here say there were many causes of Rural Metro's problems, including hostility from unionized firefighters across the New York region who conducted a campaign intended to make residents of Rye Brook fear that they were being inadequately protected by the company. There was also hostility from volunteer firefighters who saw the company as a threat to old social traditions in many small towns.

For firefighters everywhere, the arrival of the company was a fundamental threat, said Anthony Pagano, president of the Yonkers chapter of the International Association of Firefighters, a union. ''People might say, 'Maybe it's better that we go cheaper,' '' Mr. Pagano said today. ''But, you know, bean counters are counting beans, while we are fighting fires. That's dangerous to firefighters.''

Perhaps the biggest challenge to the privatization experiment was the bitter dispute that the arrangement set off between Rye Brook and the neighboring village of Port Chester. The feud aggravated old divisions between the wealthy village of Rye Brook, most of whose residents are white, and Port Chester, with its more racially diverse and blue-collar population.

Before Rye Brook decided to hire a private company, it paid Port Chester $725,000 a year to provide fire protection. The amount was almost half of Port Chester's fire budget.

Although Rye Brook officials had not expected any short-term savings with Rural Metro, they had hoped to gain a more effective firefighting service by acquiring control of firefighters and having firefighting equipment within the village.

In what Mayor Cresenzi said was an effort to sabotage the experiment here, Port Chester said it would not to respond to calls for help from the private Rye Brook firefighters.