A bitter feud over a 357-acre parcel in eastern Loudoun County, which began when the National Wildlife Federation sold a nature preserve to a developer, was put on hold yesterday when the original owner of the property temporarily withdrew a lawsuit against the environmental group.

An attorney for Claude Moore, a 95-year-old multimillionaire who gave his property to the Wildlife Federation in 1975, voluntarily dropped the litigation filed in Loudoun County Circuit Court. Moore had recently sued the group and the developer to reclaim the property, saying its sale to a developer violated the terms under which he had donated his farm to the federation.

Moore and his attorney said they had withdrawn the suit only to bolster their case, and that a new lawsuit with broader allegations against the federation would be filed soon.

Their statements seemed to ensure that the future of the Claude Moore property, which Loudoun County officials hope to purchase and turn into a public park, would remain ensnared indefinitely in a complicated and acrimonious legal tangle.

"I have no intention of accepting a compromise," Moore said yesterday. "We're holding their feet to the fire."

The dispute began in 1986, when the federation announced that it had sold for $8.5 million the property where it operated the Claude Moore Conservation Education Center to Miller and Smith Land Inc., which planned a subdivision that included 1,350 town houses.

Wildlife Federation officials said they would use the money to create a fund, in Moore's name, to protect endangered species.

Jay Hair, president of the federation, said he had been eager for a trial to begin so allegations that the group had abandoned its commitment to preserving the environment could be dispelled.

"We were anxious to get the wrongs righted by the court," Hair said, adding that he considered yesterday's action a "face-saving" device by Moore and his attorney, and that he did not expect a new suit to be filed.

Hair acknowledged that the notion of a conservation group selling a nature preserve to a builder sounds contradictory. But he said the group's resources are far better spent protecting endangered species around the world than running "a private park for Loudoun County."

Hair said his group had offered to sell the Claude Moore property to the Loudoun County government at a "nominal" price, but that the offers were spurned.

After the sale to Miller and Smith, Loudoun officials and voters alike came to support the idea of a park on the Claude Moore property. Last fall, voters authorized the county to issue up to $15 million in bonds to buy and develop a county park on the site, which is situated in one the most rapidly growing sections of Northern Virginia, not far from Dulles International Airport.

Loudoun County Attorney Edward J. Finnegan said he is negotiating with Miller and Smith to buy the property. However, those negotiations are clouded not only by the uncertainty -- prompted by Moore's suit -- over who actually owns the property, but also by a separate suit filed by Miller and Smith against the county government.

Miller and Smith, in a pending case, contend that the Loudoun County Board of Supervisors unfairly rejected its rezoning request for the Moore property last year.

Finnegan said that if his negotiations with Miller and Smith fail, the county could begin legal procedures in an effort to gain the property by condemning it. Should they succeed, a judge would determine fair compensation for the developer. Finnegan added that the county is considering a lawsuit of its own that would ask a judge to determine who holds legal title to the property.