A Northwest Washington estate once controlled by a Lebanese politician who was recently assassinated may soon be sold to investors who want to build 45 luxury homes there.

But there are still several hitches, including zoning questions, neighborhood concerns and a pending lawsuit.

The 16.2-acre tract on Foxhall Road was once the site of the grand mansion of art impresario Duncan Phillips, who founded the Phillips Collection. Raha III, a company owned by Lebanese billionaire Rafiq Hariri, bought the property in 1987 for $13 million and demolished the 38-room mansion about a year later. The vacant land is assessed at a little more than $12 million, with a proposed value of $13 million in tax year 2006.

In 2003, Hariri's company filed a permit to build a 103,667-square-foot home there, which would have been one of the largest houses ever built in the United States.

But a Raha III spokesman, Rafic A. Bizri, said Hariri wasn't serious about the venture. "It was all a conceptual idea," Bizri said last week.

Hariri, a former Lebanese prime minister who was one of the richest men in the world, was killed when his motorcade was bombed in Beirut Feb. 14. The incident, in which 19 others died and about 100 were wounded, ignited mass protests that helped force Syria to end its 29-year military presence in Lebanon.

Raha III entered into negotiations to sell the Washington land more than a year before Hariri died, Bizri said.

A group of European and U.S. investors, under the name First Capital Trust, a Miami Beach company, signed a preliminary contract to buy the property in June 2004. William Pryor, an investor who lives in Rome, is a principal in First Capital Trust and a newer investment participant, Phillips Park LLC. The price has not been disclosed.

Pryor said this week, "My intention is to see the development become part of the neighborhood so that anyone going there in 10 years' time will not be able to tell the difference" between what he plans to build and the luxury homes already in the neighborhood.

"There is no chance that we will not buy it. I have a substantial deposit down," he said.

Still, there are possible problems:

* Pryor's group has said it won't actually complete the deal until it gets written approval of its plans from the city's Board of Zoning Adjustment. The board approved a variance at its April 5 meeting, but has yet to release its order and a long list of conditions meant to respond to community concerns about wetlands protection, traffic patterns and grading changes on the steep property.

* A local environmental group, Friends of Whitehaven Park, is also awaiting that document. Lawyer William Snape said the group might sue if the language does not sufficiently protect wetlands on the site and the nearby Whitehaven national parkland to its south. The same group three years ago cited similar concerns in blocking development of a D.C. mayoral mansion on a big estate that borders the other side of the park.

* A multimillion-dollar federal lawsuit has been filed against the prospective developers by Rockville developer Theodore M. Visnic Jr. The suit alleges that Visnic was cut out of the deal after introducing the buyers to the site and doing the groundwork for the lengthy zoning presentation. The suit also claims that Visnic had been given the "exclusive right to build on all lots" and that his firm is owed at least $222,000 for work already done.

The developers have denied the allegations and filed a countersuit, claiming there was no written agreement with Visnic to build on all the lots and that the parties did not agree that Visnic or his company "would be a purchaser."

Foxhall Road has been abuzz with controversy for years as the grand estates built along the road in the 1920s and '30s have been sold off.

The Cafritz property immediately to the north of Hariri's land was sold for about $9 million in 2000 to the Field School despite neighbors' concerns about traffic problems.

The Brady estate immediately to the south was bought in 2001 by the Eugene B. Casey Foundation for $16.5 million, a price that set a residential record for Washington.

But after the mayoral mansion idea ran into flak, the foundation sold the 16.5 acres a year ago to the Friends of St. Patrick's, a parents' group associated with St. Patrick's Episcopal Day School. The school declined at the time to disclose how much was paid, but a Casey representative had sent a letter to prospective bidders saying it was accepting bids starting at $25 million.

On the Phillips estate, 13 houses can be built as a matter of right. The prospective buyers originally sought zoning approval to build 47 new luxury homes, but have agreed to 45 to meet community concerns.

Architect Anthony "Ankie" Barnes of Barnes Vanze Architects Inc. in Georgetown, who has been working on the drawings during the past year, said he anticipates the houses will run 4,000 to 5,000 square feet and the lots will average 11,000 square feet. Prices are expected to range from at least $2 million to $4 million.

But the neighbors say they are worried about how the development will affect traffic, wetlands, grading of the steeply sloping property and their daily life during construction. Different sets of neighbors, however, testified for different approaches on where to put a new entrance road and traffic light, so some will be disappointed no matter what the zoning board rules.

Staff researcher Richard Drezen contributed to this report.

A sketch of the 38-room Phillips mansion, which was torn down in 1988.