MILAN, Italy – Models refused to pose, photographers stilled their flashes, and stylists laid down their brushes for three hours yesterday to protest the lack of rules governing their industry in Italy’s fashion capital.

“When you go to New York or Paris, there are rules you have to follow. You need a visa to work, or a license,” Guido Dolci, the president of Assem, an association that represents some of the largest fashion agencies in Milan, said.

“But when people come to Milan, there are no rules. I have worked in the industry for 25 years, and I see many agencies that come to Milan and do work without any permits.”

“This is not a war between the United States and Italy or France and Italy. This is a war on those who are not aware of the damage they are doing to our system,” Mr. Dolci said. “We are suffering from the international competition.”

The strikers are pressing for a licensing system for agencies coming from abroad, and regulations that would require, for example, an agency to deposit money in an Italian bank before beginning work to ensure people working on a shoot get paid.

Mr. Dolci also would like to see a rule requiring at least half the content of an Italian-based fashion magazine to be produced in Italy.

“Obviously, if you need a picture of a building in New York City, you need to go there. But if it is studio work, it could be done here,” Mr. Dolci said. “Often they say, ‘Oh, we need the light of New York, or the light of Los Angeles.’ But the light in New York is not different from the one here. This is just an excuse.”