Amid popping champagne corks, cheers and not a few tears, the Jenco clan of Joliet, Ill., today celebrated the release of the Rev. Lawrence Martin Jenco from almost 19 months of captivity in Lebanon.

"We're ecstatic!" said John Jenco, a nephew of the Roman Catholic priest. "I'm happy as hell. It's the best news any of us could imagine . . . . It's like Lazarus being raised from the dead. But our hearts are still heavy for the other hostages."

In Joliet, a small industrial city southwest of Chicago, the bells of seven churches pealed forth the news today that the city's missing son had been freed. More than 50 members of the Jenco family live here, and several gathered overnight to await news.

Over the months of Jenco's captivity, his older sister, Mae Mihelich, was the chief family organizer of efforts to publicize her brother's captivity and gain his freedom. Today, family members gathered at Mihelich's small house to await official word and, finally, to talk with the missionary.

"He sounded fair," the priest's nephew, John, said. "I wouldn't say he sounded in good condition. He sounded like a man who had been in captivity for 19 months." Jenco was abducted Jan. 8, 1985, in Beirut, where he was director of Catholic Relief Services.

One of the priest's sisters, Sue Franceschini, fainted after speaking with her brother but quickly recovered.

Jenco spoke from Damascus, where he was staying with the U.S. ambassador to Syria, William L. Eagleton Jr., before being flown to Wiesbaden, West Germany, for a thorough medical examination and interviews by State Department officials.

The Jenco neighborhood today reflected the family's long vigil. Yellow ribbons, by now a well-known American symbol of waiting for return of a hostage, encircled trees around the houses. A sign on the Mihelich lawn that had marked the days was changed to read: "Fr. Martin Jenco, American Held Hostage in Lebanon, Released July 26. 564 Days. Amen."

The priest's brother, John, told reporters that the last report he had of the hostages was from Benjamin Weir, a Presbyterian minister who had been captured by the Moslems and released last Sept. 14.

Jenco said Weir told him the priest had been held in solitary confinement, chained and blindfolded, since his capture. But Weir said he and the priest were held together in captivity after his own abduction, and their captors allowed the two to speak and pray together.

Another nephew said his uncle "wanted me to call the Sutherland and Jacobsen families relatives of Thomas Sutherland, 55, and David Jacobsen, 55, two of the four other Americans still held captive in the Middle East . He said he saw their loved ones yesterday and he wanted to tell them that."

Jenco said in Damascus that he had talked with Jacobsen, Sutherland and Associated Press correspondent Terry Anderson before his release.

A family member told reporters that until today, the family had last heard from Jenco in November 1985, when they received a letter from him. Several months later, he was shown in a Lebanese news photo with six other hostages.

Shortly after the abduction last year, the priest's brother, John, recalled for reporters that Jenco, a member of the Order of Servants of Mary, "always said that if he were to die, he'd like to die as a missionary."

But today, Lois Jenco, a sister-in-law, said the family first began hearing of the priest's possible release late Friday. That led to flurries of phone calls among the family, and from outsiders, and a night of scant sleep, she said. "But it seems like a case of extra adrenalin is keeping us all going. We're elated that this is finally over.

"We never gave up hope, we knew this day would come . . . . We were always sure of that. There was an inner force that comes from our Roman Catholicism that sustained us."

A family group will fly to Wiesbaden for a reunion with the priest by Monday, relatives said.

According to news reports, the Shiite Moslem kidnapers of Jenco said they released him because his health was deteriorating. The family says the priest suffers from high blood pressure. Several times during his captivity, special medicine was sent to him via relief agency channels, family friends said today.

"His condition requires a very rare kind of medicine for the heart," said Sherry Hayes, a staff aide to Sen. Paul Simon (D-Ill.), who worked closely with the family during Jenco's captivity.

"A little-known procedure through intermediaries was used to replenish the medicine," she said. "It was a high-risk situation."

Later today, the Jenco family was scheduled to participate in Joliet's annual Waterways Days, a civic event celebrating the city's extensive canals and river frontage. Relatives were to ride a boat named "Freedom," and 563 helium-filled balloons were to be released -- one for each day of his captivity.

"I just wish it were all of the hostages," remarked nephew John Jenco. "But we'll keep it going."