The NSA, with help from American telecommunications companies, obtained access to streams of domestic and international communications, said the Times in the report late Friday, citing unidentified current and former government officials.
The story did not name the companies.
Since the Times disclosed the domestic spying program last week, President Bush has stressed that his executive order allowing the eavesdropping was limited to people with known links to al Qaeda.
But the Times said that NSA technicians have combed through large volumes of phone and Internet traffic in search of patterns that might lead to terrorists.
The volume of information harvested from telecommunications data and voice networks, without court-approved warrants, is much larger than the White House has acknowledged, the paper said, quoting an unnamed official.
The story quoted a former technology manager at a major telecommunications firm as saying that companies have been storing information on calling patterns since the Sept. 11 attacks, and giving it to the federal government. Neither the manager nor the company he worked for was identified.
Former Senate Majority Leader Tom Daschle said the use of warrantless wiretaps on American citizens was never discussed when Congress authorized the White House to use force against al Qaeda after the Sept. 11 attacks.
In an article printed Friday on the op-ed page of The Washington Post, Daschle also wrote that Congress explicitly denied a White House request for war-making authority in the United States.
"This last-minute change would have given the president broad authority to exercise expansive powers not just overseas ... but right here in the United States, potentially against American citizens," Daschle wrote.
"The Bush administration now argues those powers were inherently contained in the resolution adopted by Congress — but at the time, the administration clearly felt they weren't or it wouldn't have tried to insert the additional language," the South Dakota Democrat wrote.
Daschle was Senate Democratic leader at the time of the Sept. 11, 2001, terrorist attacks on New York City and Washington. He is now a fellow at the Center for American Progress, a liberal Washington think tank.
The administration formally defended its domestic spying program in a letter to Congress late Thursday, saying the nation's security outweighs privacy concerns of individuals who are monitored.
In a letter to the chairs of the House and Senate intelligence committees, the Justice Department said President Bush authorized electronic surveillance without first obtaining a warrant in an effort to thwart terrorist acts against the United States.
"There is undeniably an important and legitimate privacy interest at stake with respect to the activities described by the president," wrote Assistant Attorney General William E. Moschella. "That must be balanced, however, against the government's compelling interest in the security of the nation."
Mr. Bush has acknowledged he authorized such surveillance and repeatedly has defended it in recent days.
But Moschella's letter was the administration's first public notice to Congress about the program in which electronic surveillance was conducted without the approval of a secret court created to examine requests for wiretaps and searches in the most sensitive terrorism and espionage cases.
Moschella maintained that Mr. Bush acted legally when he authorized the National Security Agency to go around the court to conduct electronic surveillance of international communications into and out of the United States by suspects tied to al Qaeda or its affiliates.
CBS News correspondent Jim Stewart reports that, in addition to questions about the legality of the program, another question certain to be asked by Congress is what the secret surveillance accomplished.
So far the White House has