Osama bin Laden was working to assemble a team of militants to attack the U.S. on the 10th anniversary of 9/11, according to communications Navy SEALs seized from his Pakistani hideout when they killed the al Qaeda leader this spring.

Bin Laden and his operations chief, Attiyah Abd al-Rahman, swapped views about the composition of the attack team, with bin Laden repeatedly rejecting names that Mr. Rahman suggested, according to U.S. officials familiar with the intelligence taken from the bin Laden compound.

The...