NEW YORK >> The city’s newest and tallest observation deck will offer an interactive immersion in all things New York as it shuttles visitors 102 floors into the sky and provides panoramic views of the city and beyond, from the harbor to Westchester County, Long Island, New Jersey and Pennsylvania.

A projected 3.5 million visitors a year to the three-level observatory at 1 World Trade Center will be able see the history of New York City on video screens, punch up the number of available seats for a Broadway show or a Yankee game and glimpse Rockefeller Center, the Verrazano-Narrows Bridge, West Point and MetLife Stadium in New Jersey.

When the observatory opens more than 1,230 feet above Vesey Street in 2015, it will take its place among the highest decks in the nation, passing the one at the Empire State Building by a few feet but falling roughly 10 stories short of the Willis Tower Skydeck in Chicago.

At its board meeting on Wednesday, the Port Authority of New York and New Jersey is expected to approve a 15-year deal with Legends Hospitality Management to operate the observation deck that, officials say, could generate as much as $875 million in revenue for the authority over the life of the contract.

The contract is yet another indication that the 1,776-foot tower is nearing completion, a symbol of what officials say is the resilience of New York after the 2001 attack on the trade center. Port Authority officials view the deal as vindication for erecting one of the most expensive office towers built in the United States, at more than $3 billion.

Gov. Andrew M. Cuomo said in a statement released Tuesday, "Today’s announcement builds on the tremendous progress we have made at the World Trade Center site over the past couple of years and marks the continued rebirth of Lower Manhattan."

The contract will put Legends, the company that runs marketing, merchandising and luxury boxes for the earthbound stadiums of the Yankees and the Dallas Cowboys, in charge of New York’s highest perch. Although it has no experience running observation decks, Legends has guaranteed the Port Authority an annual rent and a percentage of revenues. It has brought in Phil Hettema of the Hettema Group, who developed the Amazing Adventures of Spider-Man and other theme park attractions for Universal, to design the three-story attraction, which will cost about $62 million.

Legends, led by David W. Checketts, the former president of Madison Square Garden, won a fierce competition to run the observatory.

Observatories, once an afterthought, have become a lucrative business. The Empire State Building observation decks drew over 4 million visitors last year and generated net income of $60.6 million in 2011. If all goes according to plan, Port Authority officials expect the new observation deck in Lower Manhattan to account for 40 percent of the revenue from 1 World Trade Center.

There is also lots of tower-top competition, however. The Related Companies announced last year that it had designed a multilevel observatory with an outdoor terrace for its planned 1,300-foot skyscraper at Hudson Yards on the West Side. It is unclear when that will be built.

Top of the Rock, the observation deck at 30 Rockefeller Plaza in Midtown, reopened in 2005 and now draws about 2.5 million patrons.

Legends will need ties to travel operators in Asia and Europe who buy blocks of tickets at a substantial discount for tour packages.

It is unlikely, experts said, that tourists would visit more than one observatory. At 1 World Trade Center, visitors will enter one of five dedicated elevators that rise to the 102nd floor, where there will be a theater presentation, which opens up to reveal the views, and an event space for private parties. There will be a restaurant and gift shop on the 101st floor and another observation deck on the 100th floor.

© 2013 The New York Times Company