GROUP IN BEIRUT SAYS IT HANGED U.S. COLONEL; 2D THREAT ISSUED; BUSH CONVENES SECURITY PANEL; Videotape Released

A terrorist group in Lebanon said today that it had hanged a hostage Marine colonel, and distributed a grisly videotape that showed a figure identified as the American twisting at the end of a rope.

A second group, one of many Shiite Muslim cells with links to the Party of God, a pro-Iranian organization in Lebanon, threatened to kill a second American hostage by nightfall on Tuesday unless Israel freed a Muslim cleric abducted from Lebanon on Friday.

The group that said it killed the marine, Lieut. Col. William R. Higgins, had threatened to hang him after Israel abducted the cleric, Sheik Abdul Karim Obeid, a fiery Shiite preacher and a senior leader of the Party of God. Israeli Suggests a Trade

The sheik was seized with two companions in an Israeli commando raid on the southern Lebanese village of Jibchit. A Lebanese neighbor of the sheik was killed by the Israelis.

This afternoon, a few minutes after the announced deadline for Colonel Higgins's killing, Defense Minister Yitzhak Rabin offered to trade Israel's Lebanese prisoners for all the hostages, Israeli and Western, held by Shiite groups in Lebanon. [ Page A7. ] The Organization of the Oppressed on Earth, a Shiite Muslim cell with links to the Party of God, had said it was responsible for kidnapping Colonel Higgins, the chief of an observer group attached to a United Nations truce-monitoring force in Lebanon, on Feb. 17, 1988. 'An Opening Gift'

The group said today in a typewritten statement to Western news agencies in West Beirut that it killed Colonel Higgins, calling the action ''an opening gift'' to Israel and the United States.

Accompanying the statement was a grim half-minute videotape, the first half gray and grainy, showing a man dangling from a noose, his bare feet bound, his head tilted to the left and his body turning slowly. The camera panned up the body, showing the man's face half-covered with a white gag.

The second segment showed a closeup of a face identifiable as that of Colonel Higgins, the eyes bulging slightly. The statement and tape were delivered to Western news agencies at 4 P.M. Beirut time. The statement said he had been hanged an hour earlier.

''Since criminal America and the Zionist enemy did not take our decision to execute American spy Higgins seriously, and since Sheik Abdul Karim Obeid and his two brethren were not freed by the specified deadline, the execution of American spy Higgins was carried out by hanging exactly at 3 P.M.,'' the statement said. Threat Against 2d Captive

The message was quickly followed by a warning from another group, calling itself the Revolutionary Justice Organization, threatening to kill Joseph James Cicippio, a 58-year-old American who was acting comptroller of the American University of Beirut when he was kidnapped on Sept. 12, 1986 A threat to kill the British hostage Terry Waite, an aide to the Archbishop of Canterbury who was kidnapped while trying to arrange the release of hostages, was delivered after the message about Colonel Higgins. It came in a telephone call to The Associated Press bureau in Nicosia, Cyprus, but that threat was discounted because the kidnappers have usually left messages with news agencies in Beirut.

The message about Mr. Cicippio said: ''The organization announces its quick resolve to execute the death sentence against the American-Israeli spy Joseph Cicippio if the struggling sheik is not released by 6 P.M. Tuesday.

''Then the deadline will be set for the execution, which will be broadcast on all the screens in the world.'' Photo of Cicippio

Accompanying the statement was a photograph of Mr. Cicippio wearing a brown and pink wool sweater over a blue pullover. The presence of a photograph has become the standard means of authenticating the claims of Lebanese kidnappers.

The deadline set by Mr. Cicippio's captors falls at 11 A.M. Tuesday, Eastern Daylight Time.

The message regarding Mr. Cicippio arrived at An Nahar, Beirut's most respected independent newspaper, whose offices are in West Beirut. It came five hours after the message announcing the death of Colonel Higgins.

Despite the videotape, it was far from clear that Colonel Higgins was in fact hanged.

There have been several unconfirmed reports that Colonel Higgins was killed earlier. One such report held that he was killed after the U.S.S. Vincennes shot down an Iranian jetliner on July 3, 1988. Last December, his kidnappers said they referred him to a special court, which sentenced him to death. There have also been rumors among United Nations personnel in southern Lebanon that he died of maltreatment after an escape attempt. Buckley and Kilburn

Two American hostages are known to have been killed in Lebanon: William Buckley, who was kidnapped while serving as the Central Intelligence Agency station chief in Beirut, and Peter Kilburn, a librarian at the American University of Beirut. Six other hostages of various nationalities are known to have been killed, and another is missing and presumed dead.

Islamic Holy War said it killed Mr. Buckley in October 1986 in retaliation for what it called American complicity in an Israeli air strike against Palestine Liberation Organization offices in Tunis. But American intelligence officials believe that he died in Iran earlier while being tortured.

Colonel Higgins, a decorated Vietnam veteran and a former aide to Defense Secretary Caspar A. Weinberger, was seized in February 1988 by bearded gunmen as he drove near the port city of Sidon.

Today's statement said he was hanged at the precise hour set for the release of Sheik Obeid. The hour was set in an ultimatum issued on Sunday ''as a lesson and punishment because the United States and Israel had not taken the threat seriously.'' Accused of C.I.A. Role

It was not known where Colonel Higgins was being held. The videotape today showed no evidence of where he might have been hanged. In a succession of statements in the last year, the captors accused the American of using his United Nations position as a cover for spying activity for the C.I.A.

The Organization of the Oppressed on Earth is widely thought to be the most radical of the Shiite groups operating in Lebanon. The same group asserted responsibility for the hijacking of a TWA ariliner in Beirut in June 1985. In that hijacking, one passenger, Robert Dean Stethem, a United States Navy diver, was killed.

The statement today did not say what the organization intended to do with Colonel Higgins's body. In April 1986, Mr. Kilburn, 61, was killed and his body dumped in the hills outside Beirut along with two British hostages after the American air strikes against Tripoli and Benghazi in Libya.

In October that year, Islamic Holy War said it killed Mr. Buckley, who was abducted in March 1984. Trained by Iran

Mr. Buckley's body was never recovered. Two years ago, Islamic Holy War offered to exchange Mr. Buckley's remains for Palestinian prisoners held by Israel. Despite repeated denials of involvement in hostage-taking, the Party of God, indoctrinated, financed and supplied by Iran, is often mentioned in news reports as the umbrella group for organizations holding Western hostages in Lebanon.

West Beirut and other Muslim areas in Lebanon were paralyzed by a general strike today. It was called by the Party of God and the other Shiite militia, Amal, to protest Sheik Obeid's abduction. Both the Party of God and Amal, which have long been rivals, ordered mobilizations hours after Sheik Obeid's abduction was reported. Their leaders earlier this month announced after holding talks in Teheran that they decided to end their conflict and join hands in fighting Israel.

A spokesman for Amal said the group will not agree to swap an Israeli Air Force navigator for Sheik Obeid.

The aviator was captured by Amal militiamen two and half years ago when his jet was shot down during a raid on south Lebanon.

A senior Party of God leader, Sheik Hussein Musawi, had already said that exchanging Sheik Obeid for three Israeli soldiers held by the fundamentalists was out of the question. The three soldiers were captured during a raid north of Israel three years ago. Outrage in Middle East

NICOSIA, Cyprus, July 31 (AP) -Reports that Colonel Higgins was hanged by his pro-Iranian captors prompted outrage in the Middle East today and criticism of Israel's abduction of Sheik Obeid.

Syria, which supported Iran in its war with Iraq, said, ''Killing Higgins, who was not guilty of anything, is a crime that violates all humanitarian principles and norms.'' Iran did not comment after the announcement of the hanging of the colonel, but a leading official earlier defended the kidnappers' threats to kill him.

''It is very natural that the Islamic clergy and militant groups throughout the world will take action against the interests of Israel and the United States,'' the Interior Minister, Ali Akbar Mohtashemi, was quoted as saying in an official Iranian report monitored here. Foreign Minister Ali Akbar Velayati said that ''the threat against Higgins has nothing to do with us,'' adding, ''We condemn any kind of kidnapping or death threat.''

Nasouh Majali, Jordan's Information Minister, called the report ''horrible.'' Before the report that Colonel Higgins was killed, Mr. Majali called the abduction of Sheik Obeid ''an act of terror.'' He said Israel was ''condemning terror and they are using the same means.''