The developers of PortAmerica, a billion-dollar project slated for the shores of the Potomac River, said they will formally submit detailed plans today for a "new visual gateway to Prince George's County" whose centerpiece will be a 52-story skyscraper, the tallest structure between New York and Atlanta.

The development, which received county zoning approval in 1983, is also to include a gold-domed hotel, 1,200 luxury condominium, town house and apartment units, a 250- to 500-slip marina, shops, a waterfront promenade and a community center resembling a New England town hall.

But what its developers call the "visual [and] economic landmark" for the entire project will be the multisided $175 million tower, to be topped by a 50-foot ornamental spire. The skyscraper will house the Washington World Trade Center, under plans developed by Alexandria builder James T. Lewis and New York architects Philip Johnson and John Burgee.

"The PortAmerica development is also proposed as a new functional, economic and cultural focus for Prince George's County," says the general concept plan being submitted to the county planning staff. Although the project passed its major hurdle when the County Council approved its zoning, the detailed plans now being presented also must be approved by the planning board and the council.

Before construction of the skyscraper can proceed, Lewis also must obtain certification from the Federal Aviation Administration that its height will not hinder landings and departures at nearby National Airport. The developer's lawyers say the location is out of the flight path.

An FAA spokesman said the agency has held informal discussions with the developer but no determination can be made about the building before a formal request is made.

Even before its official unveiling, the project's towering office building has won wide acceptance from county officials and politicians, who seek upscale growth to improve Prince George's image and tax base.

Some said in interviews that they are especially pleased to see a landmark skyscraper in their county, which for years has been scorned and derided by its neighbors. "I hope people don't take potshots at the building because of its height," said Lewis, who also is building the three 17-story Tycon Towers at Tysons Corner. "Within its context, it is not obtrusive."

The skyscraper is to be located half a mile from the river bank, between the Capital Beltway and Oxon Hill Road, with direct access to and from Rte. I-295. About 6,500 persons are expected to be employed inside the glass tower. The building is to be flanked by two 3,000-car parking garages. No rooftop restaurant is planned, but an observation deck may be built.

"People are truly excited about it," said County Council Chairman William B. Amonett, a real estate appraiser and broker. "It's one of the most dramatic and beautiful buildings I've ever laid my eyes on."

From Konterra on the north to the Bowie New Town Center on the east and PortAmerica on the south, developers are finding fertile ground for their projects in the populous but still largely undeveloped county.

Opposition to such growth has centered on a small, vocal group of activists, including some who live near the PortAmerica site. Nonetheless, more than two years ago, the Prince George's County Council unanimously approved overall zoning for the project. The opponents filed a court suit but lost, and now are conceding defeat.

"Of course we're upset" about the size of the trade center building, said Carmen Anderson, one of the critics. "But I sort of throw up my hands. There's not a damn thing we can do about it."

Lewis said he wants to break ground during the summer, but he first must secure final approvals from the county planning board. "I don't have a problem with it," said the board's chairman, John W. Rhoads. "This has got to be a real landmark you'll be able to see from all over."

County Executive Parris Glendening said he is delighted with the PortAmerica skyscraper. "It is clearly a 'statement' building," Glendening said. "The tremendous amount of green space and architectural amenities in the total plan are only afforded by the possibility of doing something like this."

The office skyscraper has been designed so that its glass exterior will reflect the sunset or "whatever is going on in the environment," according to Michelle Snowden, a spokeswoman for the developer.

The building is to be 750 feet high, including the spire. By contrast, the Washington Monument, the tallest structure in the metropolitan area, is about 555 feet high. Buildings in the District are limited by an act of Congress to 130 feet, except in a small section downtown where 160 feet is allowed.

"They don't like tall buildings in Washington," architect Johnson reported after what both sides described as a courtesy meeting last month with the National Capital Planning Commission, which has jurisdiction in Washington but not its suburbs.

But, Johnson said, with the county's zoning approval of 1.1 million square feet of office space for the site, the only alternative would have been several shorter towers resulting in less open space and more congestion.

Johnson and Burgee, whose recent work includes the 54-story IBM building in Atlanta and the 60-story Transco tower in Houston as well as the Tycon Towers here, said they intend their newest skyscraper to be an "identity symbol" for PortAmerica and its commercial trade center.

"The World Trade Center required a symbolic structure," said Burgee. "It's more than an office building. No one wanted to build a cathedral here, so we're building a cathedral of commerce, which seems to be our religion these days, anyway."