Trying to save the wetlands near the Greenbelt Metro Station are, from left, Kate Spencer, Pat Blankenship, Zelda Bell and Steve Perez. (James M. Thresher - The Washington Post)

Plans for a $1‚billion shopping and office complex at the Greenbelt Metro station in Prince George's County have become bogged down as environmental concerns and a dispute over highway access to the site plague the project.

Metro's 12-member board of directors selected Metroland Developers LLC more than a year ago as its partner in developing the Greenbelt Metro station site – the county's first major project tied to a transit station.

But the development team, which includes Washington builder James Clark, whose company built FedEx Field in Landover, has been unable to finalize its deal with Metro as it seeks to resolve environmental and traffic questions.

Environmentalists want the developer to set aside more land for conservation, and state officials have yet to agree to pay for a new interchange off the Capital Beltway. The improved access is considered critical for a 123-acre shopping and office project that would include a conference center, residences and a theater.

"All of these things must come together," said Del. Rushern L. Baker III (D), chairman of the county's House delegation. "It's going to be a sticky one to get through."

Dana B. Stebbins, an attorney for the development team, said that no formal agreements have been reached with Metro or the other parties involved but that she is optimistic the project is moving forward.

"We're going to get it done," Stebbins said. "We are not at a standstill. We are not at odds."

Stebbins declined to comment further on the negotiations.

In October, the Greenbelt City Council voted to oppose a Beltway interchange that could cost as much as $34‚million, citing the extra traffic it could generate on local roadways. Greenbelt Mayor Judith F. Davis said the project is simply too big and needs to be scaled back.

"We are not against development," she said. "We've always said we are in favor of any development that is transit-oriented. It is the total scope of it that we object to."

The city's position is at odds with that of County Executive Wayne K. Curry (D) and a majority of County Council members. The council voted last year to allow the developer to build shops and homes on land that is zoned for industrial use.

"No one wants to have a site sitting there languishing and not moving forward," said P. Michael Errico, Curry's deputy chief administrative officer. He said the project as proposed "appears to be a good use of the site."

County leaders have included the interchange on their list of funding requests for the coming legislative session in Annapolis. It is No. 5 of 14 projects. Some legislators said the project may need to be moved up on the list to have a chance at funding.

Gov. Parris N. Glendening (D) has not said whether he will support funding of the interchange, although he has expressed interest in transit-oriented development in general. This year, the governor cited the Greenbelt project as a good example of "smart growth," the state policy to contain sprawl by focusing development in neighborhoods where roads and other infrastructure exist.

"Obviously the interchange is key to the whole development," said County Council member Audrey E. Scott (R-Bowie), whose district includes Greenbelt. "It has to be adopted by the legislature. It remains to be seen what will happen."

A Greenbelt area environmental group, meanwhile, has asked the state to step in and buy a portion of the property for conservation. But Glendening has said he won't consider intervening until the developer and the environmentalists reach a compromise on how much land to set aside.

"If a consensus is reached, there is interest in the state playing an appropriate role such as preserving some of the critical environmental land," said Michael Morrill, a Glendening spokesman.

Kate Spencer, chairwoman of Citizens to Conserve and Restore Indian Creek, the lead environmental group, said the dispute is focused on an area near the Metro tracks, where the developer has proposed an office building.

Spencer said the area is wetlands, and an office complex and a connecting road, which also has been proposed, would destroy the environmentally sensitive area.

"It's obvious a lot more study has to be done," she said.

The threat of environmental lawsuits and the holdup created by the opposition has frustrated the landowner, A.H. Smith Associates, a Prince George's construction supplier, which has threatened to pull out of the deal if a compromise is not reached soon, sources close to the negotiations said.

As part of its deal with the transit authority, Metroland agreed to pay Metro $300,000 in fees over the next five years. It also agreed to pay $6.4‚million for the 78 acres that Metro owns.

Denton Kent, director of property management for Metro, said he expects the deal to be finalized by late next month. "We have had some disagreements on terms," Kent said. He declined to say what those differences were.