Eight days after the Sept. 11 commission warned that the United States government is still not equipped to thwart major acts of terrorism, a Senate committee today began formally considering a far-reaching overhaul of the U.S. intelligence apparatus, promising to submit legislation to the Congress by the fall.

Sens. Susan Collins (R-Me.) and Joseph I. Lieberman (D-Conn.), the ranking members of the Senate Governmental Affairs Committee, promised on the first day of hearings since the report, to move quickly in a bipartisan fashion to overcome what Collins called "power struggles" and "turf battles" that could impede fundamental changes.

"We're going to get this job done and get it done with unprecedented thoughtfulness and speed," said Lieberman. The status quo "failed us on Sept. 11 and it will fail us again unless we act now" to implement the commission's recommendations.

They heard equally urgent calls for action from the September 11 commission leaders, Chairman Thomas H. Kean (R) and Vice-Chairman Lee H. Hamilton (D).

"We have concluded that the intelligence community is not going to get its job done unless someone is really in charge," said Hamilton. "That is just not the case now."

Three years after the attack, Hamilton said, "the government is not acting with the urgency necessary" and, in the absence of legislation and presidential action, he said, it even risks backsliding into old and discredited habits.

The committee's unusual hearing -- held in the middle of a congressional recess -- underscored the impact the best-selling "9/11 Commission Report" has had politically. The White House is also reported to be considering executive orders that would permit implementation of some commission recommendations without legislative action.

Two specific proposals were under consideration today:

* The appointment of a national intelligence director within the Executive Office of the President who would coordinate and oversee the CIA and 14 other U.S. intelligence agencies.

* A commission recommendation that would bring together CIA, military and law enforcement officials in a National Counterterrorism Center to plan operations in the United States and abroad. This latter would require lifting restrictions on military and intelligence involvement in domestic matters.

"It can be done," said Collins, citing the Goldwater-Nichols legislation that reorganized the military's command structure in 1986. "The threat today requires the same willingness to innovate."

At today's hearing, Kean and Hamilton were given an opportunity to respond to criticism of their key recommendations that has come from several quarters inside and outside of the intelligence bureaucracy, particularly suggestions that the proposals would shift too much authority to the White House while diminishing the importance of the CIA.

"Terrorism is our most important national security priority," said Hamilton. "It is inconceivable to me that the president of the United States would want his highest national security priority handled somewhere else in the government that is not under his control."

Plus, he said, "where else would you put" the power to oversee the broad and integrated needs of counterterrorism that involve law enforcement, diplomacy, covert action, tracing money and other functions scattered about the government. "Do you want to put all this authority in the CIA? Do you want to put it in the Defense Department? I don't think so."

"You cannot coordinate these activities from a single department," said Hamilton. "You have to do it in the White House."