The Northeast Washington land-owner could not understand what was going on. For weeks he had been negotiating to sell some property to a well known developer and now, just as the deal was being wrapped up, he discovered someone had put a total stranger's name on the deed.

"Jeanne McIntire? Who that?" he recalled asking when he saw the woman's name on settlement documents.

It was quickly explained to him that the deed was being drawn up that way at the request of the buyer - Nick Antonelli.

Antonelli's interest in the property - and in a number of other lots in that same Northeast block of dilapidated row houses and vacant warehouses just north of New York Avenue - was not to be shouted about the neighborhood. Antonelli, who was quietly assembling land for eventual developments, was using someone else's name on the deed, an accepted practice to help buyers disguise their land assemblies and keep prices of adjoining property down.

Antonelli and his associates have now bought up about two-thirds of the property in the long block bounded by P Street NE on the north, North Capitol Street on the west, O Street NE on the south, First Street NE on the east and Florida Avenue NE on the northeast tip.

It happens that this block is just across the street from the warehouse-office building at 60 Florida Avenue NE that Antonelli has leased to the D.C. Department of Human Resources for $5.6 million over 20 years. That lease, approved by then DHR director Joseph P. Yeldell at about the same time that Antonelli was lending Yeldell $33,000 through a third party, is the local point of last week's federal grand jury indictment charging Antonelli with bribing Yeldell.

By appearances and the assessment of some real estate experts, this part of the city is "not exactly a hot property." After serving as the location for years of building, storage and repair businesses, it fell on hard times after the 1968 riots.

Antonelli himself began buying property there in June, 1976, when he bought the 60 Florida Avenue NE building and more than 100,000 square feet of vacant land across the street from it for $800,000.

He then began adding to his holdings - using Jeanne McIntire's name rather than his own - buying other lots in the block across Florida Avenue, accumulating pieces to a puzzle whose future shape was known only to him.

Most of the property Antonelli has accumulated in the block is currently unused and produces no income.But real estate sources say Antonelli's lone-term 60 Florida Avenue lease with the city could enhance the value of those other properties and offset losses he could incur while waiting to redevelop the block he has been buying up.

Antonelli's purchase of property in the block in the name of 60 Florida Associates, a partnership in which Antonelli is the principal stockholder, according to real estate and corporate records. The property he bought then included much of the eastern half of the block and some additional lots that adjoined land owned by Cohen-Meisel Associates, another large property owner in the same block.

Cohen-Meisel Associates, which bought its property there in 1970, is a partnership headed by the sons of the late developer William Cohen. Until his death in 1974, the elder Cohen had joined Antonelli in many land investments, including the purchase of the Mayflower Hotel. The Cohen-Meisel partnership has also teamed with Antonelli in real estate development projects, land records indicate.

An even closer Antonelli associate, Angelo Puglisi, had preceded Cohen-Meisel Associates in buying property in the block. In the fall of 1976, Antonelli purchased a lot adjoining two that Puglisi had bought in 1967.

Puglisi, a real estate broker, is a 20-year business associate and close friend of Antonelli. They have been partners together in numerous business entreprises over the years. An associate who has worked with both men describes Puglisi as someone who frequently serves as Antonelli's real estate scout, sometimes buying property in his name but with Antonelli's money.

Five other lots in the block are listed in land records as having been bought by Jeanne McIntire, the substitution of whose name for Antonelli's on one deed had surprised a property owner selling to Antonelli. The McIntire lots also adjoin those already owned by Antonelli or his associates.

Jeanne McIntire was once a secretary to Mitchell Blankstein, Antonelli's corporate attorney. Lots in her name were acquired in September and October of 1976, and land records show she listed her address as the same DeSales Street NW office thatserves as Antonelli's business headquarters.

Besides the lots he has bought so far, there is another important piece to Antonelli's land assembly across the alley that runs through the middle of theparcels he own in the block. Right after he began buying property there, Antonelli asked the city to close the alley so that he could combine his lots "to consolidate the site for future redevelopment."

In an alley closing application filed in late June 1976, ANtonelli asked permission to close the eastern portion of the alley, known as Decatur Street NE. He apparently dropped the request last February when utility firms and the fire department raised objections.

Without the alley closing, Antonelli could siill construct new buildings on the property he owns in the block. But he would not be able to build as large a structure as would not be able to build as large a structure as would be possible if he could combine all his lots and the alley.

In the meaantime, Antonelli could still operates a PMI auto maintenance and car wash shop on his block. And he has opened a new PMI parking lot on the O Street NE side of the block.

There have been recent indications that the area around Antonelli's block may be revitalized and that Antonelli's property there will prove to be a good investment. City officals say nearby neighborhoods have been targeted for federal and city renovation projects and these efforts could increase the value of property there within 10 years at most.

Bill Carter, of the city's Department of Housing and Community Development, said the city urban renewal agency has purchased 119 properties on Bates Street NW, just a half block southwest of ANtonelli's holdings, and has been planning since 1969 to rehabilitate the mostly vacant Bates Street row houses for resale to low and middle-income residents.

In addition, Carter said, another group of houses is being privately built on the site of the OLd Embassy Dairy on First Street NW, Between Florida Avnue, Q and Third Streets NW.