On Sunday night, New York Times Executive Editor Bill Keller told Jeff Fager, executive producer of CBS's "60 Minutes," that the story they had been jointly pursuing on missing Iraqi ammunition was starting to leak on the Internet.

"You know what? We're going to have to run it Monday," Keller said.

The paper's front-page story, charging that 377 tons of powerful bomb-making material "vanished sometime after the American-led invasion last year," hit the presidential campaign with explosive force, as Sen. John F. Kerry seized on it for three straight days and President Bush accused Kerry yesterday of making "wild charges."

The article has also sparked criticism of the two news organizations from some conservatives, who accuse the Times and CBS of orchestrating a late hit against Bush.

Keller said in an interview yesterday that campaigns "attack the messenger" when they do not like the message. "Beating up on the so-called elite media has a nice populist ring to it, and some of it is calculated," he said. Bush campaign officials thought that "if they barked at us, we would back off. . . . We've vetted this every way we can, and we continue to do that."

Keller said "60 Minutes" executives asked the newspaper to hold the story until this Sunday so they could report it the same day, and "we said we weren't comfortable doing that because it wouldn't give the White House a fair opportunity to respond."

Fager dismissed criticism of the timing as "absurd," saying "it was a breaking news story and a significant one. It's impossible to manage these things." He said "60 Minutes" and correspondent Ed Bradley had planned to break the story this Sunday -- two days before the election -- only because "the story came to us on relatively short notice" and that was the next available show. The program has a separate staff from "60 Minutes Wednesday."

Fager said it was "incredibly unfair" to link the ammunition story to the earlier "60 Minutes Wednesday" report on documents about Bush's National Guard service, which CBS has admitted it cannot authenticate.

A Bush campaign release Tuesday accused the Times of publishing a "false story," without elaboration. Critics on the right say the story was overblown.

Weekly Standard Editor Bill Kristol said the front-page piece, while accurate, was "somewhat hyped" and that it "didn't put it into context how important 380 tons are when there are tens of thousands of explosives in the country." He also called CBS's plan to report the story Sunday night "really kind of stunning."

The Wall Street Journal editorial page questioned the article's timing. Among Fox News commentators, Bill O'Reilly questioned whether it was "a legitimate story or a dirty trick," while Tony Snow said the article "looks pretty bogus" and is "an embarrassment to the New York Times and also CBS."

The principal uncertainty about the story involves the timing of the ammunition's disappearance. The White House says the explosives may have gone missing while Saddam Hussein still controlled Iraq.

"Sure there's a possibility" that happened, Keller said, "and I think the original story accounted for that possibility. . . . I don't think we've ever claimed there was a definitive answer to what became of this stuff."

Bush campaign officials point out that Kerry's foreign policy advisers cannot say for sure what transpired. Richard C. Holbrooke told Fox that "I don't know what happened," and Jamie Rubin told CNN it was "possible" the weapons were removed by Hussein. A top Republican strategist said the Times did not spell out the possibility that Hussein moved the ammunition and that CBS was planning a last-minute "ambush on the president."

Kerry spokesman Chad Clanton deflected questions about whether the Democratic nominee was going beyond the available evidence in assailing Bush for "incredible incompetence" and using the Times headline in an attack ad. "This is a devastating report for the Bush administration," Clanton said. "The president could clear this up if he would come forward and tell us what happened."

There have been reports for 18 months about the looting of Iraqi weapons. What three Times reporters wrote Monday, days after getting a tip from a "60 Minutes" producer, was that Iraq's interim government had warned U.S. and international inspectors earlier this month that 377 tons of explosives were missing.

NBC's Jim Miklaszewski, who was embedded with the Army's 101st Airborne Division during the war, reported Monday that the unit visited the Qaqaa weapons facility on April 10, 2003, and never found the explosives.

Anchor Tom Brokaw clarified the next night that "we simply reported that the 101st did not find them. For its part, the Bush campaign immediately pointed to our report as conclusive proof that the weapons had been removed before the Americans arrived. That is possible, but that is not what we reported." The Times on Tuesday quoted the unit's commander as saying his troops had stopped at the facility but did not search it.

Keller said the original story noted that the Qaqaa facility had last been visited by U.N. inspectors in March 2003, and quoted a letter from a senior Iraqi official saying that the stockpile disappeared after early April 2003 -- during the war -- because of theft and looting. Other than some last-minute checks and editing on Sunday, Keller said, "the story was basically ready."

The New York Times article was "basically ready," Bill Keller said.CBS's Jeff Fager had asked the paper to delay publication a week.