D.C. mayoral aide Joseph P. Yeldell halted his initial efforts to arrange a city government lease for a Northeast Washington building immediately after learning that the lease would probably not go to millionaire developer Dominie F. Antonelli Jr., according to court testimony yesterday.

Yeldell, then head of the D.C. Department of Human Resources, allegedly reversed signals in October 1973 when he was told that the city planned to lease the building from Emanuel Logan, a businessman who had reportedly offered to charge the District government substantially lower rent than Antonelli had proposed.

Yesterday's testimony by several city government officials, who appeared as prosecution witnesses in Yeldell's and Antonelli's bribery and conspiracy trial, was the first to point to Yeldell's personal involvement in DHR's efforts to lease the two-story office building at 60 Florida Ave. NE.

The prosecution has alleged that after halting the negotiations in October 1975, Yeldell later overcame a series of other city government obstacles to clear the way for an eventual $5.6 million, 20-year lease DHR lease for the Florida Avenue building from a partnership controlled by Antonelli. In return, the prosecution has charged. Yeldell received help from Antonelli in obtaining several personal loans, including a $21,500 loan from a bank in which Antonelli is a major stockholder and a $33,000 loan made secretly to Yeldell by Antonelli himself.

George A.C. Crocker, a DHR employe, testified yesterday that Yeldell first indicated interest in the Florida Avenue building in the early summer of 1975 - at about the same time that Antonelli, according to earlier testimony, had taken his first steps to buy the building from its previous owner, Peoples Drug Stores.

"I received a [telephone] call from Mr. Yeldell, and he mentioned some space on Florida Avenue," Crocker told the U.S. District Court jury. Crocker said that Yeldell had erroneously referred to the building's address at 2 Florida Ave. NE, but he added that he immediately told Yeldell the correct address. "I told him I would take a look at the [building]," Crocker added.

Sam D. Starobin, director of the city's Department of General Services, then testified that he received a letter from Yeldell, dated Aug. 8, 1975, saying that DHR wanted to lease the Florida Avenue building.

In mid-September of 1975, Starobin said, he received a phone call from Yeldell, who complained that the lease negotiations for the Florida Avenue building were "dragging." Starobin testified that Yeldell told him "that it was important that it [the lease] be consummated and that I help expedite it."

Shortly afterward, Starobin said his agency decided to rejecet Antonelli's proposals for the Florida Avenue building and to try to conclude a lease with Logan, who was also apparently seeking to purchase the building from Peoples. Starobin said he informed DHR officials of his department's decision at a meeting on Oct. 1 1975.

John Wilson a former DHR employs who attended the Oct. 1 meeting, told the federal jury yesterday that he immediately went to the phone and called Yeldell to tell him the city had been "successful at getting the (Florida Avenue) property (from Logan) at a lower price" - about $2 less per square foot in annual rent, he said.

Yeldell, who previously had pressed for the Florida Avenue lease, now responded coolly. Wilson's testimony indicated. Yeldell expressed doubt about the lower rent proposal. "He wanted to know how that was possible," Wilson said. Yeldell then told Wilson something "to the effect that perhaps we should look at this more carefully," Wilson testified.

Two days later, Starobin testified, he learned from another DHR official that DHR was "reconsidering its need for the space [at 60 Florida Ave. NE] and [that DGS should] not proceed [with the lease] at this time." Later in October, Starobin said, DHR officials told him they "definitely didn't want to proceed with the lease."

The prosecution contends that Yeldell later revived his plans for leasing the 60 Florida Ave. NE building from Antonelli's partnership after getting Mayor Walter E. Washington to give DHR its own powers to lease such buildings. Starobin noted in his testimony yesterday that this leasing authority was transferred from his department to DHR by a mayoral order in December 1975.

There has been no testimony thus far, the prosecution acknowledged yesterday, that shows whether Yeldell actually knew that Antonelli was negotiating to buy the Florida Avenue building at the time DHR was seeking to lease it. Defense lawyers have argued that the eventual lease between DHR and Antonelli's partnership was properly negotiated, entailed no wrongdoing and was highly advantageous to the city government.