Attorneys for the U.S. government agreed yesterday to delay closing an 800-bed shelter for the homeless operated by the Community for Creative Non-Violence (CCNV) until a federal judge decides whether the facility President Reagan promised to transform into a "model" shelter should be renovated.

In an unusual hearing, U.S. District Judge Charles R. Richey, who is considering a lawsuit by CCNV, said he was considering calling city officials, including Mayor Marion Barry, to testify about relocating shelter residents. Last week the federal government announced it planned to close the downtown shelter on July 10 and would give the District government at least $2.7 million to help house residents.

"Why don't we get [Corporation Counsel] Ms. Inez Reid and the mayor here to do something about this?" asked Richey, who said he was concerned about the fate of residents of the shelter at 425 Second St. NW.

City officials said they were mystified by the judge's statement and concerned about possible involvement in an acrimonious dispute between CCNV and the Reagan administration.

"It's not clear to me what [Richey] means," said Audrey Rowe, D.C. commissioner of social services. Rowe said that hours before the hearing CCNV leader Mitch Snyder told her he would sue the District if it helped the federal government relocate residents of the shelter.

"I need these kind of threats like a hole in the head," Rowe said. "At this point we're just sort of waiting to see what the outcome of this lawsuit is going to be." Rowe said her staff is drawing up relocation plans to be submitted to Barry today.

Richey said he planned to proceed "on a very tight schedule" and scheduled crucial motions for July 5.

When CCNV attorney Florence Roisman, who is working alone and for free, indicated she could not meet Richey's deadline, the judge was skeptical.

"From the newspaper I see Mr. Snyder has said he had many lawyers available," said Richey, referring to a recent statement by Snyder in The Washington Post. "Couldn't he get somebody else?"

When Roisman, who faces a team of high-level government lawyers, said she had not found another lawyer willing to donate some time, Richey said he would appoint someone to help her.

During a lengthy recess in the three-hour hearing, Richey called senior partners at two leading Washington law firms, Covington & Burling and Wilmer, Cutler and Pickering. Neither firm immediately agreed to the judge's request and Richey said he expected to appoint a lawyer today.

Richey temporarily denied a motion by Roisman that he visit the shelter located three blocks from the courthouse.

He also barred CCNV from taking the deposition of Health and Human Services (HHS) Secretary Margaret Heckler until after July 5, when the government is expected to argue that CCNV's lawsuit should be dismissed and the shelter closed.

As lawyers for both sides prepare for next week's hearing, Snyder plans to lead a march from the shelter to the White House tomorrow. The march, he said, is an attempt to dramatize President Reagan's promise two days before last November's election to transform the rat-infested building into a "model" shelter for the homeless.

The alliance between Snyder and the administration was severed last week when HHS officials, with the approval of White House chief of staff Donald Regan, announced they planned to close the shelter by July 10. They also ordered CCNV, which occupies the federally owned facility with the government's permission, to vacate the building, which will probably be razed.