Mayor Bloomberg is challenging any assumption that the Democrat seeking to become the city’s first Latino mayor, Fernando Ferrer, has a lock on the Hispanic vote.

Mr. Bloomberg has already assembled an elaborate operation of Latino supporters, with roles played by the activist Fernando Mateo, the entertainer Willie Colon, and the longtime state legislator Olga Mendez.

“I think people assumed he would give up on the Latino vote, now that Ferrer was running,” the president of the Institute for Puerto Rican Policy, Angelo Falcon, said of the mayor. “In fact, we have seen a lot more activity from Bloomberg, some people would say, than the Ferrer campaign.”

Two of Mr. Bloomberg’s seven campaign chairmen, Mr. Colon and Herman Badillo, are of Puerto Rican background, as is Mr. Ferrer. Mr. Colon, the salsa legend, has served as an adviser and liaison to the mayor’s Latin Media Entertainment Commission, and Mr. Badillo, Mr. Bloomberg’s opponent in the 2001 Republican primary, has attributed his current enthusiasm for Mr. Bloomberg to the mayor’s commitment to stopping “social promotion” of students in public schools.

In addition, the Bloomberg campaign last month announced an outreach campaign to Hispanic New Yorkers, naming Mr. Mateo, a Dominican entrepreneur and activist who created the Toys for Guns program and is president of the New York State Federation of Taxi Drivers, as director.

Although the other campaigns have all said they appeal to Latino voters, none of them, including the Ferrer campaign, has nearly the number of Hispanics in top leadership positions that the Bloomberg campaign boasts. Calls to the Ferrer campaign were not returned.

Some observers said Mr. Bloomberg – who is said to study Spanish every day – has made a calculated investment to appeal to the Latino community.

“When he became a candidate for public office in 2001, he did an extraordinary thing that never really has been done in New York public office,” lobbyist and former adviser to Governor Cuomo, Tonio Burgos, said. “He spent an extraordinary amount of time on Spanish media and print. He had the resources to do it, but I think he did it in a very smart way.”

This year’s launch has already begun. Last week, Hoy and El Diario/La Prensa, the city’s major Spanish-language print outlets, ran feature stories on Mr. Bloomberg’s efforts to reach new Hispanic voters.

The Bloomberg campaign tapped a former reporter for Hoy and New York 1, Maxy Sosa, who is an immigrant from the Dominican Republic, to direct Spanish communications. Mr. Mateo said his vision is to recruit for his outreach team, which currently also includes New Yorkers of Puerto Rican and Venezuelan backgrounds and members who are Mexican, Colombian, Peruvian, and Ecuadorian.

“This isn’t about one or two groups,” Mr. Mateo said. “This is about New York.”

Spokesmen for the Bloomberg campaign said they are responding to shifting demographics. New York’s Puerto Rican community has diminished in recent years, while the Dominican community remains the city’s largest immigrant group, with more than 360,000 foreign-born members. Voting blocs from the other immigrant groups continue to grow as well.

Almost the entire increase in first time votes in the 2004 presidential election – 185,000 – is attributable to immigrants, according to a recent study. Moreover, those new voters seemed more inclined to vote Republican than are native New Yorkers.

The study, directed by a political scientist at Barnard College, Lorraine Minnite, found 18% voted Republican compared with 15% of native New Yorkers. What’s more, in the 2002 race for governor, 47% voted for the Republican, Governor Pataki, compared with 32% of native-born New York City voters.

The potential of immigrant Latinos to shift the election is one the Bloomberg campaign appears poised to jump on.

“We’re running a very different type of Hispanic political outreach campaign, different from any in the history of the city,” Mr. Mateo said, speaking last week from the Bloomberg campaign’s Midtown headquarters.

“We’re recruiting leaders from every area of the city that become our captains, and they will recruit others to become our soldiers,” Mr. Mateo said. “What we want to achieve here is a consensus where all the Latin American communities come together and support the mayor.”

Still, Mr. Mateo, well-known in the Dominican community and a prominent GOP activist who spoke at the Republican National Convention, could also be a liability, according to some community members.

An El Diario/La Prensa columnist, Gerson Borrero, reported last month that various Latino Bloomberg campaign insiders were upset by the appointment.

“A look behind the curtains at Bloomberg for Mayor 2005 finds a firing squad shooting itself,” Mr. Borrero wrote in Spanish, referring to the team recruited by the mayor.

Some of the other Latino advisers, who include a deputy mayor under Mayor Giuliani, Ninfa Segarra; a veteran state senator, Ms. Mendez, who was soundly defeated last fall, and an internist, Ramon Tallaj, who revived the Upper Manhattan Republican Party, were not pleased with the decision, Mr. Borrero wrote.

“He is very publicity-oriented, but half the time he is pushing himself,” Mr. Falcon said of Mr. Mateo. “Having him on board is like having a little box of nuclear energy that can blow up on you.”

Mr. Mateo, for his part, said he has emphasized to his team that there is just one message: Mayor Bloomberg.

Any backlash against himself, Mr. Mateo said, is just from “other people who wanted this position and didn’t get it.”

“We’re like a boxer,” he said. “We’re training, and we started this election early. We want it so when November 8 comes around we will be ready to fight.”