OAKDALE, LA., NOV. 27 -- An anticipated agreement with Cuban inmates at the federal detention center here for the release of their 26 remaining hostages failed to materialize tonight, dampening the hopes of 300 hostage relatives who had spent several hours at a nearby church preparing to celebrate.

Sen. John B. Breaux (D-La.) said the Cubans' four representatives had been unable to persuade all of the estimated 1,000 inmates to support the pact reached Thursday with federal negotiators. The inmates then tried to amend the agreement, Breaux said, leading to what he called a "temporary stalemate."

Tonight, Justice Department spokesman Mark Sheehan said negotiations had been discontinued for the rest of the evening and that no new talks had been scheduled for Saturday. "At present, there's no time set to resume the negotiations," he said.

"I'm disappointed that the Cubans did not follow through on the apparent agreement we had" Thursday night, Breaux said. A videotape made then showed an inmate and a federal negotiator shaking hands on the deal and agreeing that a typed copy of the pact would be signed this morning.

The inmates torched buildings and took 28 hostages last Saturday after the State Department announced the revival of a plan to deport about 2,500 of the 125,000 refugees who arrived in the 1980 boatlifts from Mariel, Cuba. The rioting spread Monday to the Atlanta Federal Penitentiary, where negotiations with about 1,000 Cubans holding 94 hostages also were inconclusive today. {Details, Page A15.}

One hostage was released here Thursday night in an apparent gesture to seal the agreement. A second hostage, a prison counselor, was released this morning after being stabbed in the neck by an inmate who had been detained in the center's mental health unit.

In the eerie, rain-soaked calm that surrounded the center early this morning in anticipation of a settlement, six inmates emerged into the center about 7 o'clock carrying counselor Manuel Cedillos Jr. on a stretcher formed by their joined hands.

Immediately afterward, more than 50 inmates delivered fellow prisoner Moreno Rallao to federal authorities at the center's entrance. Rallao was in handcuffs.

Cedillos was listed tonight in fair condition at Humana Hospital here and was reported later to be in good spirits.

Justice Department spokesman Sheehan said this morning that authorities did not ask for Rallao. "The detainees brought him out. I think they were anxious to be rid of him," he said. Sheehan added that he did not think the incident will affect final negotiations over the agreement, but the anticipated time of the hostages' release, 1 p.m., passed with no apparent progress.

At an afternoon briefing in Washington, J. Michael Quinlan, director of the U.S. Bureau of Prisons, said the Oakdale negotiations were "very close" to a resolution. But he acknowledged that the timing of the briefing, set for 3:30 p.m. EST and finally held at 4, turned out to be "a little optimistic."

At about the same time, after two afternoon negotiating sessions here, some inmates had picked up a large bedsheet banner that has hung for at least a day on the center grounds and were parading it before television cameras. It read: "U.S. Government Please Allow

Us to Speak With Someone We

Can Trust Who Speaks Our

Lang{uage}."

Then, federal authorities ordered camera crews to leave the negotiating area and restricted them to views of the rubble in the detention center yard.

More discouraging news came from officials of the U.S. Immigration and Naturalization Service who were heard over a radio requesting space heaters, raising the possibility that the stalemate might last for some time.

Breaux told reporters that the general components of the agreement reached Thursday included a moratorium on deportations, quick reviews of each inmate's immigration status, and amnesty in the rioting and hostage-taking.

Earlier in the week, Attorney General Edwin Meese III had offered a moratorium on Mariel deportations and case-by-case review of each inmate's status, if the uprisings ended here and in Atlanta.

Quinlan, of the Bureau of Prisons, said that once the uprisings here and in Atlanta are brought under control, authorities plan to disperse the 989 Cubans here and the 1,128 remaining at Atlanta among 15 other federal prisons and to house those with mental problems in medical facilities.

"I'm concerned that every time we make an offer, someone can find something to add to it," Breaux said. He added that he did not think a language barrier or a lack of trust was holding up the release of the hostages.

"I think it's a problem of add-ons," he said, but he would not disclose the changes proposed by the inmates.

Breaux said the hopes of hostage relatives were raised "as high as they could possibly be" Thursday when a television camera crew filmed the handshake between the inmate representative and the federal negotiator. The hostage who was freed then, corrections officer William Hoffpauir Jr., told reporters this morning that the hostages were well cared for.

"The treatment that we received was respectful," he said. "We were constantly reminded that they had no ill feelings toward us."

Hoffpauir said the hostages received food, drinks and cigarettes from inmates who "apologized for the situation." But he added an ominous note: "At all times," he said, "protection was provided from factions that could have presented danger to us."

That statement later was taken as the first concrete evidence that the inmate negotiators might not be speaking for a decisive majority of the prisoners.

As night fell, the inmates hoisted another banner. This one read, "We Want Archibishop San Roman, Our Legal Representatives and Live National Press Inside Before We Sign the Agreement -- or No Agreement." The banner referred to Auxiliary Bishop Augustin Roman of Miami.

Steven Donziger of the Atlanta-based Coalition to Support Cuban Detainees said that the refugee advocates had worried earlier in the day that without legal representation, the inmates might begin to suspect that the offer was unfair and cause negotiations to break down.

Breaux said tonight that the talks had stopped while inmates consider their next moves.

At the Sacred Heart Church nearby, where hostages' waiting families were secluded from the media, the clusters of yellow helium-filled balloons they had planned to let fly when the hostages emerged at least temporarily had lost purpose.

The inmates "could walk out in 10 minutes and say, 'Here are your hostages,' " Breaux had said earlier. "We don't know."

Emergency team tends to hostage stabbed in neck by inmate detained in the mental health unit.