The Port Authority declined to comment on any negotiations with tenants. Stephen Sigmund, a spokesman for the authority, did say, “There is clearly momentum both in the building of the World Trade Center site and the growing interest from potential tenants.”

Condé Nast’s current landlord at 4 Times Square, the Durst real estate family, whose building played an important role in rejuvenating Times Square, is also on the verge of playing a larger role at 1 World Trade Center. On Thursday, the Port Authority’s board is expected to grant initial approval to a deal in which the Durst family would take over marketing and leasing the downtown skyscraper and pay $100 million for a 10 percent stake in the project.

After the attack on the trade center, many who had worked there said they had no desire to return. Eliot Spitzer once called it a white elephant. Douglas Durst, who headed the family firm, was one of many opponents.

Goldman Sachs and Merrill Lynch both turned down entreaties to move to one of the new skyscrapers planned for the site. With no private corporations on the horizon, city, state and federal agencies promised to lease several million square feet. Critics, however, bemoaned the cost of the towers and the foolishness of installing government employees in prime office space.

If the deal is completed, Condé Nast would take up to one million square feet in the 2.6 million-square-foot, $3.3 billion tower sometime in 2014, according to two executives who have been briefed on the agreement. The company and the Port Authority expect to spend the next couple of months working out the details. It was unclear how much the company would pay in rent, but it appears to be trying to replicate its strategy in Times Square by securing below-market leases as a pioneering tenant.

Condé Nast, whose 18 magazines are spread among six buildings, including 4 Times Square, declined to comment, but in a letter to employees on Tuesday morning, it said the move “would allow us to house all our brands in a single, state-of-the-art headquarters.”

If the lease is signed, it would almost certainly mean that the authority would not have to lease as much, if any, space to state and federal agencies. With Condé Nast as a magnet, the tower would command higher rents from companies.

“This represents a game-changing transformation of Lower Manhattan into a hub for creative industries, not just for financial services,” said Robert Yaro, president of the Regional Plan Association. “It’s been almost a decade since 9/11, and clearly people are now looking at this site and this building as one of the most well-located addresses in the region, not just as the site of a national tragedy.”