After months of pummeling by unions, luminaries of the opera world and company members, Mr. Steel, the general manager and artistic director of New York City Opera, presented his plan for a peripatetic company uncoupled from its Lincoln Center home.

Most of next year’s four-opera season was already known — a “Traviata” and Rufus Wainwright’s “Prima Donna” at the Brooklyn Academy of Music; a “Così Fan Tutte” at John Jay College; a Telemann opera at El Museo del Barrio.

But Mr. Steel also disclosed that a City Opera partnership with the Public Theater would bring a Shakespeare-based opera to the Delacorte Theater in Central Park in the fall, part of what is expected to be a continuing joint venture. Tickets will be free, he said.

Other details, mostly casting, emerged. The Brooklyn native and up-and-comer Laquita Mitchell will sing Violeta in “La Traviata.” The Telemann opera will be “Orpheus.” Melody Moore will come back to the company to sing the title role in “Prima Donna.” She appeared last season in “Séance on a Wet Afternoon,” by Stephen Schwartz.

Along with presenting the details, Mr. Steel used the news conference to make the case for his vision and to rebut criticism, which has become increasingly personal, of the decision to leave Lincoln Center.

He appeared in the cool confines of the theater at the Guggenheim Museum just minutes after a lively demonstration in the broiling sun outside on Fifth Avenue by some 50 people, including members of the opera’s chorus and orchestra and three Democratic elected representatives from the Upper West Side: New York State Senator Tom Duane, Assemblywoman Linda B. Rosenthal and City Councilwoman Gale A. Brewer.

The rally, organized by the orchestra and chorus unions, was intended to denounce the move and efforts to turn the orchestra and chorus into essentially freelance outfits. A flier accused Mr. Steel of “utter incompetence, ineptitude and a skewed artistic vision that sells no tickets.”

Inside, Mr. Steel came out from the wings with Mark Newhouse, a prominent City Opera board member. Mr. Newhouse described the company’s mission as presenting traditional and rarely heard operas and introducing new talent, which he said would continue under Mr. Steel, whom he called “endlessly creative, energetic and intrepid.” The chairman, Charles Wall, was out of town, a spokeswoman said.

Mr. Steel said City Opera was “open for business” but had to leave its Lincoln Center home, the David H. Koch Theater, “because we can’t afford it any longer.” He said that 14 staff jobs had been eliminated and that the company could not survive without major changes to the union contracts, which he said were created for a scale of performance that City Opera can no longer sustain.

The company next season plans 16 staged opera performances, all with supertitles, far fewer than in past years. “We’re trying to pay people for the work that they do,” Mr. Steel said of the chorus and orchestra, which would give up guaranteed minimum work weeks and minimum membership numbers under the company’s contract offer.

Mr. Steel suggested that the union protests were “political theater which can obscure more than uncover.” When asked about the personal attacks, he said, “I guess it’s a strategy some people think is effective.”

He said that the future of the annual Vox showcase of new opera, a major resource for composers and contemporary-music lovers, was up in the air. Noting that it was a way to keep the orchestra working during idle weeks, he said, “We’re trying to find a way to continue it.”

Mr. Steel cast the company’s move out of Lincoln Center as an opportunity to bring opera to the people, likening New York to a “glittering theater with eight million seats.”

“We are coming out to meet the people of New York,” Mr. Steel said. He said the company could always return for performances at the Koch Theater and was considering appearances at the Rose Theater, City Center and Broadway houses, as well as in Staten Island, the Bronx and Queens.

He argued that leaving Lincoln Center would not discourage subscribers, who would be signing up for tickets at three separate theaters next season. “People in New York go to see what they want to see,” he said, not to the nearest opera house.