A developer hoping to build the 1,510-foot American Commerce Center at 18th and Arch streets has fielded many questions as the project has moved through the city's bureaucracy since June.

The unanswered question: What companies would call the $1.1 billion skyscraper home?

Peter Kelsen, an attorney for the developer, told a City Council committee yesterday that the tower could house three big corporate tenants. He suggested that at least one potential tenant already has offices in the city while others could be lured from Montgomery County and New Jersey.

"They're household names," Kelsen said later, declining to identify them because the project still needs other city approvals.

The committee approved a zoning change that the developer needs to build a densely packed building on half a city block. Council could grant final approval for that zoning by next Thursday. Council and the City Planning Commission would then have to sign off on a plan of development.

Opponents from nearby condo and apartment buildings on JFK Boulevard have complained that the project will tower over their homes, blocking out the sun and snarling already bad traffic.

Hill International Real Estate Partners proposes a 1,210-foot office tower topped with a 300-foot spire and a 477-foot adjacent hotel, attached by a sky bridge over a public plaza below. It would be 50 percent taller than the Comcast Center, one block away.

Stephen Mullin, a consultant hired by the developer to study the project's financial impact, said that the timing could work well with the current economic turmoil because it would be ready "to start early on the upturn of the next [economic] cycle."

Mullin estimated that the city could collect $15 million in taxes for the tower construction and then $20 million a year in local taxes after the building is filled with tenants.

Joseph Beller, an attorney for neighborhood residents opposing the tower, said that Council should consider the consequences of a big building on a small lot.

"Our concern is that this is just too much density for this area," Beller said.

"You can build it new. You can build it pretty. But you don't have to build it this big," he said. *