A month after the TWA hostage crisis ended, a picture of the Hezbollah organization believed to be behind the hijacking is emerging that shows it to be made up of several groups with a variety of goals and little central control rather than a tightly knit organization.

There are also increasing signs that the seven Americans kidnaped in Lebanon over the past 17 months and still held captive by Shiite extremists are caught up in what U.S. intelligence sources describe as the "tribal" aspects of Hezbollah's diversity.

Interviews with Hezbollah officials in recent months also have made clear that at least one faction of the Shiite Moslem-dominated Hezbollah movement has been financed by Iran, but that country's role in its direction remains unclear.

Sheik Abbas Mussavi, interviewed by Agence France-Presse in Lebanon's Bekaa Valley last month, said money to support Hezbollah "mainly comes from Tehran." Mussavi endorsed an Iranian-sponsored idea to turn Lebanon into an Islamic republic, and said Ayatollah Ruhollah Khomeini "is Hezbollah's supreme leader and Hezbollah receives all its directives from him."

Another pro-Iranian in Hezbollah, Sheik Ibrahim Amin, told Washington Post special correspondent Nora Boustany in June that the movement got financial and ideological aid from Iran.

Mussavi reportedly is one of the three chief leaders in Hezbollah (Party of God), a radical Shiite Moslem movement that held hostage several of the TWA passengers. U.S. officials have sought to determine who was responsible for the hijacking and the murder of a U.S. Navy enlisted man aboard the plane.

Mussavi's remarks also point to divisions within Hezbollah that may have played a significant role in the hijacking and the involvement of the Islamic Amal movement and Syria in its outcome.

Such divisions, if confirmed, could also have significance for attempts to gain release of the seven other American captives in Lebanon, who may be in the hands of the most radical part of the Hezbollah movement.

Hezbollah has been viewed by some outside analysts as a tightly organized religious movement dedicated to propagating the Islamic fundamentalism of the Shiite minority, through terrorism if necessary. But increasingly there are signs it is loosely organized, with factions that compete with each other on many issues.

The history of its development suggests to some Middle East experts that Hezbollah is not an identifiable political party created by the injection of Iranian Revolutionary Guards in Lebanon's Bekaa Valley, but rather the embodiment of a two-decade revolt by Lebanon's Shiites. That revolt has its roots in the long-held feeling of suffering by Shiites in Lebanon, many of them descendants of Shiite families in Iran and Iraq.

These family connections seem to have helped pave the way for the Iranian leaders to exploit the vacuum left by Lebanon's unstable government and factionalism to gain political support among Shiites.

U.S. officials also believe that family ties are important in the continuing detention of the seven kidnaped Americans. The principal demand for their release has been that Kuwait free 17 men convicted in that Persian Gulf emirate of the 1983 truck bombings of the American and French embassies and Kuwaiti facilities.

The group holding most of the Americans is believed to include relatives of at least one of the Arabs imprisoned in Kuwait. The truck bombings, which killed five persons, are thought to have been carried out by members of Al Dawa, a terrorist group made up of Iraqi Shiites opposed to the Baghdad regime and supported by Iran.

Since the 16th century, when Shiism became Iran's dominant religion, a close relationship has existed among Shiites in Iran, Iraq and Lebanon.

Middle East specialists in Washington say they have established that Iranian Prime Minister Mir Hussein Mussavi, Hezbollah's Abbas Mussavi and Hussein Mussavi, the spokesman for Lebanon's Islamic Amal movement, are all descendants of a prominent Shiite family that lived in Iraq's Najaf region two generations ago.

Abbas Mussavi, a Lebanese citizen, is believed by anti-Khomeini Iranians and staff members of Sen. Jesse Helms (R-N.C.) who have been investigating Iran's connections with Middle East terrorism to be about 30 years old. His father, Mohammed Mussavi, is an Iranian clergyman who went to school with Khomeini in Iran's holy city of Qom and later joined him in exile near Paris.

Mohammed Mussavi and his Iranian wife have a son, Mohammed Mohsen Mussavi, who was Iran's charge d'affaires in Lebanon and was kidnaped there in 1982. He is still missing. He is a cousin of Prime Minister Mussavi.

Reportedly more friendly to the Syrians is Hussein Mussavi of Islamic Amal, who broke with Nabih Berri's mainstream Amal in 1982.

Also often mentioned as spokesman of Hezbollah, with close ties to Iran's leaders, is Mohammed Hussein Fadlallah. Although a Shiite leader, he is believed to be a Lebanese nationalist.

Both men are believed to have played a role in the release of the TWA flight's hostages after being asked by the Syrian president to intervene.

But in an interview with Reuter this week, Hussein Mussavi said groups of fighters are independent. "Nobody can impose anything on the others," he said. "I am directly responsible for Islamic Amal. I don't know what the others are doing although I support them in most that they do."

The emergence of Hezbollah in Lebanon has raised differences among its leaders about Iranian assistance and the issue of setting up an Islamic republic there. Some of the leaders are strongly pro-Iranian and others -- the more secular Shiite leaders, gathered under the Syrian umbrella -- largely seek only political superiority.

Some, like Abbas Mussavi, call the Iranian revolution "a model for Lebanon" and say their goal is an Iranian-style Islamic republic there.

Fadlallah, a longtime associate of Iran's leaders, is an example of how Iran's expansionism has disappointed some Lebanese Shiites. He once backed Iranian intervention in Lebanon, but he told Middle East Insight magazine recently he was against establishing an Islamic republic there because "Lebanon's situation is different from Iran's."

But an editorial in a recent issue of Qods, published by supporters of Khomeini here, indicated what Iran's current goal in Lebanon may be, saying: "The Islamic movement in Lebanon has taken a major step toward the setting up of an Islamic state on the Mediterranean coast."