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 plans were only in the discussion phase, U.S. officials said. They haven't seen any signs the nascent plot ever went beyond the early planning, the officials said.

Still, earlier this month in his first meeting with senior staff at the Central Intelligence Agency, acting Director Michael Morell told his staff that one of their top priorities would be to make sure that neither that plan nor any others were carried out.

Plans for an anniversary attack were one of the few specific potential threats to emerge from the trove of documents and other materials taken from bin Laden's residence in Abottabad, Pakistan, in the May 2 raid. An initial analysis of the evidence said al Qaeda hoped to attack trains in the U.S., possibly on the anniversary of Sept. 11.