British Hostage Freed; American May Follow : Lebanon: Journalist McCarthy carries secret letter from Islamic captors for U.N. leader. A French volunteer worker is reported kidnaped.

Islamic Jihad released British television newsman John McCarthy after more than five years of captivity Thursday, charging him to deliver a secret letter to U.N. Secretary General Javier Perez de Cuellar with proposals for an end to the cruel chapter of Western hostages in Lebanon.

The release of a second hostage, perhaps American journalist Terry A. Anderson, who has spent more time under terrorist detention than any other Westerner, was widely expected.

The smiling 34-year-old McCarthy, looking healthy and almost jaunty in a olive polo shirt, arrived in Damascus under Syrian military escort after his release by his Islamic fundamentalist captors somewhere in Lebanon. He brought out word that at least three of 11 known hostages left--Anderson, American academic Thomas M. Sutherland and Church of England official Terry Waite--were “in good health and good spirits.”

McCarthy, who was en route to the Beirut airport for a flight to England when seized on April 17, 1986, finally made it home aboard a Royal Air Force plane that, after a flight from Damascus, alighted at Lyneham air force base in Wiltshire, west of London at 10:30 p.m. Thursday.

Freedom for McCarthy ushered in a day of dizzying and sometimes confusing activity dealing with the Western hostages still left in control of various pro-Iranian Muslim fundamentalist groups in Lebanon:

* At United Nations headquarters in New York, the secretary general told reporters that he believes that a second hostage, most likely an American, will probably follow McCarthy into freedom soon. McCarthy is expected to deliver the Islamic Jihad letter to Perez de Cuellar in Europe on Sunday.

* Perez de Cuellar’s optimism about the impending release of an American was soon echoed somewhat by President Bush. But the President also cautioned: “The evidence is not all that hard. We keep getting assurances through third parties, but that’s not good enough for me.”

* As if to lend meaning to these doubts, a terrifying complication loomed in Beirut. A mysterious group of Islamic fundamentalists, obviously at odds with Islamic Jihad, announced the kidnaping of a Frenchman as a new hostage and threatened to kill him if any other hostage was released.

* This latest kidnaping underscored reports, confirmed in effect by McCarthy upon his release, that some broad agreement to the hostage crisis was under negotiation--a deal that could see the release of about 400 Lebanese and Palestinian prisoners from an Israeli detention camp in southern Lebanon and the concurrent release of seven Israeli soldiers believed held by Islamic fundamentalists in Lebanon.

The Former Hostage

In Damascus, McCarthy, articulate though sometimes hesitant with emotion, held up a brown envelope for journalists assembled in a hall of the Syrian Ministry of Foreign Affairs. The envelope contained the missive for Perez de Cuellar.

Although he had not read it, the freed hostage said, “I understand that the letter seeks the secretary general’s help in arranging the release of all prisoners and hostages being held in Lebanon and for those held in Israel.”

Later, looking remarkably fit and chipper on Syrian television, McCarthy elaborated. Based on talks with his captors, he said, “I believe they have decided that what they want now is exchange for their people, the Lebanese held in Israel. . . . That is what they are holding us for now.”

McCarthy also said that he had been held captive with Anderson, Sutherland and Waite and “I am happy to be able to tell (their) families . . . that when I left them two days ago, they were in good health and in good spirits, and that our living conditions recently are tolerable, and I think we could call them good.”

But McCarthy said that the 52-year-old Waite, who was seized in 1987 while trying on behalf of the Archbishop of Canterbury to negotiate release of the hostages, “had been very sick” with “a very bad problem with his lungs--asthma.” Waite, however, had improved after medical care, McCarthy said.

The British TV producer said that his first two years of captivity had been difficult and “there were times when it seemed it would never end.” But, he went on, “in the past three years, certainly in the last two, conditions have improved a lot.”

“I think for all of us it was a constant strain, a constant pressure on us, and we had to keep ourselves happy and determined to carry on,” McCarthy said. “We have done that very well, I think.

“The men that I was with, Terry Waite, Terry Anderson, Tom Sutherland, were very strong men. They supported me and, I hope, I supported them.”

McCarthy also said that his captors had assured him that although most of the remaining Western hostages, believed to number at least 10 with McCarthy now free, were held by other Muslim fundamentalist groups, their “health and living conditions are good.”

If McCarthy’s captors were truthful, this would be the first substantive news--for years--that all the Western hostages taken over the past six years, six of them Americans, were alive and reasonably well.

McCarthy’s account also peeled back another layer of the darkness that has shielded the captivity of the Western hostages in Lebanon. Since the first, American professor Frank Regier, was snatched off a street near his Beirut home in 1984 and held for nearly two months, few details of the hostages’ living conditions have been described.

McCarthy was met in Damascus by his father, Patrick, and his brother, Andrew. His mother, Sheila, who would have celebrated her birthday Thursday, died of cancer two years ago while McCarthy was a prisoner.

His father and brother accompanied him aboard the Royal Air Force VC-10 transport plane that flew from Damascus to the Lyneham base. During the flight, the ex-hostage ate roast chicken and vegetables and had a gin and tonic.

On his arrival in England, McCarthy was driven to a VIP suite on the RAF base. He was expected to be debriefed there and examined at a nearby RAF hospital today.

The United Nations

At the United Nations, Perez de Cuellar told journalists that he had hope that a second hostage, probably an American, would be released soon. And he added pointedly, “I have reason to have hope.” But as the day wore on, it became clear that a second hostage would not be released as swiftly as some had expected.

The secretary general revealed that some semblance of negotiations were already under way. “In the last few days,” he said, “I have been in touch with all parties concerned.”

At the same time, he insisted that Islamic Jihad was releasing McCarthy and possibly a second hostage “with no conditions.” That seemed to indicate some kind of plan for Islamic Jihad to release two hostages as a sign of good faith before embarking on serious negotiations for the freedom of all the hostages.

In London, Douglas Hogg of the British Foreign Office said that McCarthy was “anxious to see the secretary general as soon as possible.” Perez de Cuellar told journalists that, since he was flying to Geneva this weekend for a conference on health and nutrition problems in Iraq, he expected to meet McCarthy on Sunday to receive the letter. “I am not sure where it (the meeting) will take place,” he said, “but it will be somewhere in Europe.”

The President

Meanwhile, at Kennebunkport, Me., where he is vacationing, President Bush met with reporters, offering them optimism laced with caution. “There’s a chance now, a better chance, that an American will be released,” he said as he was about to begin a round of golf at the Cape Arundel Golf Course.

“There are rumors--an increasing number of rumors--that an American will be freed,” he said. “There was some Lebanese source--we don’t know how strong or good it is--saying that Anderson will be released. So . . . the game goes on.”

The President ascribed “a certain cruelty” to the rumors and characterized them as “a tragic dance.” “I say tragic,” he explained, “because there’s other Americans held. I’d be delighted to see one released, but I want to see them all released.”

Missing Frenchman

In Beirut, a little-known group, The Organization for the Defense of the Prisoner’s Rights, claimed to have kidnaped Jerome Leyraud, a volunteer with the French humanitarian association Medicins du Monde, or Doctors of the World. An anonymous caller, identifying himself as a spokesman for the kidnapers, threatened to kill Leyraud if another hostage was released. The terrorist group evidently wants the Israelis to release all Lebanese prisoners first.

Although the kidnaping could not be confirmed, workers at Medicins du Monde headquarters were obviously worried. The 25-year-old Leyraud had been seen driving away from his West Beirut apartment about 2:30 p.m., dressed in shorts and carrying a towel. Neighbors assumed he had gone to the beach, but he had not returned several hours later.

When informed of the evident kidnaping in Beirut, Perez de Cuellar said, “If it is confirmed, I have to say that it will not help me in my efforts.”

The Israeli Question

All the reports of negotiations brought new attention to the position of Israel. But Israel has reacted to the demands to release its Lebanese and Palestinian prisoners with a demand of its own: an accounting of seven missing soldiers captured in Lebanon during the past decade.

“Most important for us as the first step is to get some indication that our (soldiers) missing in action and prisoners of war are alive,” said Defense Minister Moshe Arens.

He indicated that there has been no progress in finding out about the fate of the troops. No more than three are believed to be alive.

Syria holds the key to information and the release of the Israelis, Arens added. “To the best of our knowledge, our POWs and MIAs are being held on Lebanese territory patrolled by Syria. So there is no doubt that the Syrians play an important role here,” he declared.

Uri Lubrani, the Defense Ministry official in charge of hostage negotiations, indicated that Israel would take part if a hostage swap was in the works.

Israel’s prisoners in southern Lebanon, held in a buffer zone patrolled by Israelis and pro-Israeli Lebanese militiamen, are described as Palestinian and Lebanese guerrillas and sympathizers. The Palestinians allegedly tried to make attacks on Israel’s northern border.

There were differing accounts as to whether Israel would release Palestinians as well as Lebanese in the event of an exchange. There would be adverse reactions among many Israelis if Palestinians were freed, since a previous deal freed many Palestinian activists who subsequently became leaders of the Arab uprising in the West Bank and Gaza Strip.

Meisler reported from the United Nations and Tuohy from London. Times staff writers Nick B. Williams Jr. in Nicosia, Cyprus, Daniel Williams in Jerusalem and James Gerstenzang in Kennebunkport and special correspondent Marilyn Raschka in Beirut contributed to this report.