Sixty new small schools with themes ranging from firefighting to cooking to "peace and diversity" will open next year, Mayor Michael R. Bloomberg announced yesterday.

Among the new schools will be 41 high schools, 4 traditional middle schools and 15 schools based on the less common sixth- or seventh-through-12th-grade model. Three of the schools will be single-sex, four will cater to students who are behind in their credits, and each of them will ultimately have about 500 students.

The creation of small schools is a centerpiece of the overhaul of the New York City school system under Mr. Bloomberg and Chancellor Joel I. Klein. Officials hope that carving some of the city's enormous high schools into more intimate learning environments will reduce dropout rates, keep more students interested in academics and limit the number of students who get lost in the thunderous shuffle of high school.

"Small schools work better than big schools, and we're going in the direction of trying to have more small schools," the mayor said at a news conference at Park West High School in Manhattan, the future home of three new small schools. "Everybody agrees that effective small schools that provide a wide range of school options are really fundamental to the educational reform process."

The new high schools will take 100 ninth graders next year and will grow to no more than 500 students. The other schools will start with 75 sixth graders and grow to about 525.

"That is a manageable size," Mr. Bloomberg said. "It is a far cry from the schools of 3,000, where it's just probably, it's very difficult at least, to provide the attention that every one of our students needs and deserves."

Among the single-sex schools, the Eagle Academy for Young Men is being created together with One Hundred Black Men, a civic group that will "provide successful male role models," according to a description released yesterday. The Young Women's Leadership School will be modeled on a similar school in East Harlem. The Urban Assembly Academy for History and Citizenship for Young Men will emphasize "rite of passage experiences" and offer a course on hip-hop and citizenship. All of these schools will be in the Bronx. The 60 schools announced yesterday join 46 others that opened this year and more still that have existed longer. Mr. Klein has pledged to open 200 small schools by 2007 with the help of private money, including more than $50 million from the Bill and Melinda Gates Foundation.

More than half of the new schools will be run in partnership with New Visions for Public Schools, a New York group that has received millions of dollars from the Gates foundation and other charities to create dozens of schools over the last two years, many of them in the Bronx.

Most of the new schools will spring up in the Bronx and Brooklyn. Most of the high schools will be share space with large high schools, some of which will eventually close. Most small middle schools will share space with existing middle schools. The department is still trying to find space for several of the schools.

Three large high schools, including Thomas Jefferson High School in Brooklyn, which was recently labeled one of the most dangerous schools, will begin the phaseout process in September.

This year, several of the large high schools that housed small schools, including John F. Kennedy and Christopher Columbus in the Bronx, were severely overcrowded, as the small schools took up space while regular students continued to pour in.

Department of Education officials said yesterday that they would try to reduce the burdens on big schools. They said that they hoped a new high school admissions process would enable them to anticipate overcrowding hot spots more clearly and that at least $4 million would go to campuses with multiple small schools.

"We will make sure that we are doing everything possible to make these buildings work as a whole campus of schools and not to hurt other schools," said Michele Cahill, Mr. Klein's senior counselor for education policy and an architect of the small schools plan. "This is a problem that we have been spending a lot of time to address." Randi Weingarten, president of the United Federation of Teachers, stood with the mayor, chancellor and other officials during yesterday's announcement but was circumspect in her praise for the initiative, saying her union had supported the creation of small schools for two decades. Ms. Weingarten also pushed for smaller classes in all city schools, saying that while small schools benefit from the personal touch, "I would love to see all schools, big schools as well as small schools, have that kind of intimacy."

Nicholas Scoppetta, the fire commissioner, was also on hand yesterday to speak about the F.D.N.Y. High School for Fire and Life Safety, where physics classes, he said, would delve into building structures and collapses, and students would be able to earn certification as emergency medical technicians.

The Amnesty International School for Human Rights is intended to encourage students to become "compassionate, socially engaged young adults.'' The Food and Finance High School will focus on the culinary arts as well as the financial aspects of the food industry.

Students who have already been admitted to one of the city's specialized high schools will have to give up their spots if they want to apply for a slot in one of the new schools. Students who have already ranked their high school choices can re-rank them to include the small schools. Applications for middle schools will be handled through the 10 regional offices.