The city approved plans for a new skyscraper near Penn Station that will rise to within 34 feet in height of the nearby Empire State Building, inserting a glassy challenger almost next door to what has been the defining element of the city's skyline. The 47-1 City Council vote came after a fierce, weeklong public relations and lobbying campaign by the owners of the Empire State Building to stop the rival tower, contending that its bulky profile would scar the skyline and diminish the Empire State Building's iconic status. They went so far as to propose a one-third of a mile no-build zone around the Empire State Building, at 34th Street and Fifth Avenue, that would bar any developer from erecting a comparable skyscraper. But the council gave those arguments scant attention Wednesday as it approved the planned tower, known as 15 Penn Plaza, on Seventh Avenue, opposite Madison Square Garden and Pennsylvania Station. Some council members found the prospect of a new building and the developer's agreement to spend more than $100 million on improvements to subway entrances and tunnels at Penn Station far more compelling, especially during a citywide slowdown in construction. The project also had the backing of Mayor Michael R. Bloomberg, whose administration has long favored high-density development near major transit points like Penn Station, the busiest commuter hub in North America with more than 450,000 daily passengers. In part because of the proximity to transit, the developer of 15 Penn Plaza, the Vornado Realty Trust, earned zoning bonuses that will let it construct a building 56 percent larger than what would ordinarily be allowed. Bud Perrone, a spokesman for Vornado, said the company was pleased with the outcome and believed its 68-story, 1,216-foot-tall building would 'be an outstanding addition to New York's iconic skyline.' Anthony E. Malkin, an owner of the Empire State Building, said he favored development in the surrounding area, but felt that the proposed tower should be shrunk so as not to obscure the view of his building, which has stood alone since it was built 79 years ago. 'We thought that 15 Penn Plaza was too close to the 1,250-foot-tall Empire State Building for its height and design,' Malkin said. The Empire State Building, which reaches 1,454 feet when its lightning rod is included, was the tallest in the world for more than 30 years and remained the tallest in the city until the first World Trade Center was finished. After Sept. 11, 2001, it regained that status, but will fall back to second place behind the new 1 World Trade Center, which will top out at 1,776 feet. 