Zawahiri merged his group with bin Laden's in 1997 and is considered the terror leader's chief strategist and a top contender to succeed him.
Ateef's daughter recently married bin Laden's oldest son.
He serves as the chief propaganda officer for al Qaeda and many members of his group are believed to have been involved in the planning and execution of last week's attacks on the World Trade Center and the Pentagon.
U.S. intelligence agencies believe he has frequently traveled outside Afghanistan disguised as a honey salesman to make contacts with bin Laden terror cells.
Other key figures include:
Bin Laden founded al Qaeda in 1989 and has built it into a conglomerate of Islamic extremist organizations with cells operating in at least 60 countries.
According to court documents and testimony given by informers in his organization, al Qaeda is organized into a series of committees which all report to a central council that he heads.
The four main committees are:
Outside Afghanistan, the group is split into small cells of sometimes no more than four or five people.
According to testimony given by former al Qaeda operatives, each cell is made up of four separate sections:
