NAIROBI – With the death of Osama bin Laden, the future of al-Qaida remains murky, facing a potential contest for the network’s leadership between leaders of the group’s old guard and those heading newer, ambitious franchises in Africa and the Middle East, according to terrorism experts.

Initially, bin Laden’s death means that he will probably be replaced at the helm of al-Qaida by Ayman al-Zawahiri, the Egyptian surgeon who has long served as his chief deputy. Although Zawahiri has also been in hiding over the past decade, he has been the most visible face and voice of al-Qaida, issuing even more audio and video propaganda statements than bin Laden.

Zawahiri, however, is considered a polarizing figure within the top circles of al-Qaida and has long antagonized Islamic radicals from other factions. U.S. counterterrorism officials predicted he would have a much tougher time preserving unity within al-Qaida and attracting new followers.

Among other potential leaders are charismatic figures who head al-Qaida affiliates in places such as Yemen that are now regarded as even more dangerous than the one led by al-Qaida’s central command. Over the past two years, the boldest attempted terrorist attacks have been carried out from Yemen, by a group whose leaders include the Yemeni-American cleric Anwar al-Aulaqi.

“Bin Laden leaves behind a number of groups that have been deeply influenced by him. He has built a movement that will outlast him,” said Rohan Gunaratna, head of the International Center for Political Violence and Terrorism Research in Singapore.

In certain parts of the Arab world, post-Sept. 11 enthusiasm for bin Laden and his ideologies has clearly subsided. The wave of populist uprising sweeping across North Africa and the Middle East unfolded without involvement by bin Laden and al-Qaida; even Islamist movements are calling for democracy rather than the Islamic emirates that bin Laden had sought in the Arab world.

And even among the group’s supporters, the death of a charismatic leader such as bin Laden could make fundraising more difficult.

Nevertheless, bin Laden nurtured a constellation of al-Qaida franchises stretching from Africa to the Middle East, and linked by ideology and allegiance to his core values and tactics. Such franchises, say terrorism experts, were part of a grand plan by bin Laden to enlarge al-Qaida’s reach and leave a self-sustaining legacy.

Such affiliates received little, if any, financial and material support from al-Qaida’s central command in Afghanistan and Pakistan — or any directives. They operated independently, conducting their own fundraising, recruitment and strategies. Often, bin Laden and his associates would step in to offer rhetorical and theological encouragement.

Yemen, in particular, is likely to become a prominent refuge and operational arena for al-Qaida loyalists, possibly creating an even bigger challenge for the Obama administration, they said. The poor and unstable Middle Eastern nation is home to al-Qaida in the Arabian Peninsula, known as AQAP, which has tried to attack the United States twice since 2009.

Yemen will not be the only area of concern for the United States and its allies. In Somalia, al-Qaida-linked al-Shabab is seeking to overthrow the struggling U.S.-backed transitional government and turn the region into a Taliban-like Islamic emirate. In North and West Africa, al-Qaida in the Islamic Maghreb has murdered Westerners and staged suicide bombings. Kidnappings for ransom are growing, infusing large sums of cash into the group’s coffers. The group is believed to have perpetrated last week’s bombing of a popular cafe in Marrakesh that killed 16, mostly foreigners.

Al Zawahiri is the last senior al-Qaida leader wanted on charges of involvement in the Sept. 11 hijackings and the 1998 U.S. Embassy bombings in Nairobi and Dar es Salaam, Tanzania. But other figures have taken on responsibility for running the network, which historically has been dominated by Saudi, Egyptian, Libyan and Yemeni nationals.

After bin Laden, perhaps the most charismatic member of al-Qaida’s inner circle is Abu Yahya al-Libi, a Libyan field commander and self-styled radical theologian who has starred in numerous propaganda videos popular with jihadi audiences. Libi became legendary among al-Qaida sympathizers after he escaped from a U.S. prison in Bagram, Afghanistan, in 2005.

Another key figure is Adnan el-Shukrijumah, a Saudi native and Guyanese citizen who lived in the United States for 15 years as a young man. The FBI identified Shukrijumah last year as al-Qaida’s new “external operations chief.” He has been indicted for involvement in an attempted 2009 attack on New York’s subway system.

But it’s al-Qaida’s operatives in Yemen who have spawned the most concern among U.S. counterterrorism officials. Earlier this year, Michael Leiter, director of the National Counterterrorism Center, described the affiliate as posing “the most significant risk to the U.S. homeland.” On Christmas Day 2009, the group dispatched a Nigerian man to try to blow up a Northwest Airlines plane headed to Detroit; last year, it tried to blow up Chicago-bound cargo jets with printer cartridges filled with explosives.

Several of the top AQAP leaders have strong links to bin Laden from their fight in Afghanistan against the Soviets. Bin Laden’s former personal secretary, Nasser al-Wuhayshi, leads the group. Some of Yemen’s most influential figures have ties to bin Laden, including his formal spiritual adviser, Abdul Majid al-Zindani, whom the United States has classified as a terrorist.

Through his extremist English-language Internet sermons, Aulaqi has secured a large following around the world, particularly in the West. He has been linked to the man charged with killing 13 people at Fort Hood, Texas, in 2009 as well as the Christmas Day and parcel bomb plots. He is also thought to have played a role in creating Inspire, AQAP’s English-language magazine that is intended to recruit Muslims in Western nations.

A year ago, the Obama administration authorized the targeted assassination of Aulaqi, believed to be hiding in Yemen.

Bin Laden’s death arrives as Yemen is facing its biggest political crisis in more than three decades. President Ali Abdullah Saleh, a vital U.S. ally in counterterrorism, is clinging to power as momentum builds on the streets and in Arab capitals for his ouster.