The United States delivered a protest to the government of President Vladimir Putin yesterday for refusing to stop Russian arms dealers from providing illegal weapons and assistance to the Iraqi military.

Bush administration sources said one Russian company is helping the Iraqi military deploy electronic jamming equipment against U.S. planes and bombs, and two others have sold antitank missiles and thousands of night-vision goggles in violation of U.N. sanctions. The sources said Moscow has ignored entreaties from senior Bush administration officials concerned about the threat to U.S. forces.

During more than a year of intensifying discussions, the Russian officials initially denied the existence of the company that allegedly sold at least a half-dozen devices designed to confound global positioning system guidance gear used in aircraft and bombs, U.S. officials said. Later, the Russians assured the Americans that they were closely watching the company.

"The stuff's there, it's on the ground and they're trying to use it against us," said a well-placed U.S. official who requested anonymity. Of the Russians, the official said, "This is a disregard for human life. It sickens my stomach."

Administration officials have long been frustrated with Russia's failure to crack down on arms sales and technology transfers to countries the U.S. government considers state sponsors of terrorism, including Iran and Syria. The Russians offer a variety of explanations, from the argument that the goods are legal or benign to the assertion that the business is done by private firms over which the Kremlin has no control.

U.S. officials contend Russia should have been able to halt the dealings of the three companies. Unlike cases where evidence was scant or Russian inaction could be attributed to inefficiency, the Bush administration said it made certain this time that senior Russian officials in Moscow and diplomats in Washington were given detailed information.

The United States provided Russian authorities with names, addresses, telephone numbers and, in some cases, shipping dates and ports of exit, according to the U.S. official. Sensitive intelligence was declassified -- after extensive internal debate -- to inform the Russians of the specifics.

"This was Hansel and Gretel. We left bread crumbs on the street for the Russians to follow," said the official. "This was a road map. This was a neon flashing arrow."

The administration said it learned last month that an order of several thousand night vision goggles was due to be shipped by one of the Russian firms. Russian authorities were provided "enough information to stop the shipment before it went," the official said, but they replied variously by saying that only a few goggles had been given as gifts to Middle Eastern leaders or that it was the weekend and nothing could be done.

Night vision goggles have given U.S. forces a vast advantage in their ability to engage in combat at night, a superiority that would be diminished if Iraqi soldiers obtained similar equipment.

As Iraq stepped up its military procurement, the government of President Saddam Hussein increased its acquisition of antitank guided missiles produced by a firm called KBP Tula. U.S. authorities imposed sanctions on the company last year for allegedly selling antitank weapons to neighboring Syria, officials said.

Iraq purchased a "militarily significant quantity" of Kornet missiles from the company in the past two months, according to U.S. officials, who said they told Moscow that documents identifying Yemen as the purchaser of the missiles were wrong. They reported that the administration first asked Russian authorities to halt the missile sales last year.

The Bush administration reserved its highest-level efforts for halting the delivery of the jamming devices, which officials said sell for thousands of dollars apiece and can interfere with global positioning equipment important to aircraft navigation and ground forces. Guided bombs also use the technology, but are equipped with accurate backup guidance systems.

The threat was considered serious enough that very senior U.S. officials pressed the Russians to crack down on the Moscow-based manufacturer, Aviaconversiya. Appeals began at a low level in June 2002. For three months, according to the Americans, the Russians denied the company existed, despite its Internet site and extensive media coverage.

As time went on, successively higher-ranking Americans advised the Russians that the delivery of the devices "would be a violation of a number of U.N. sanctions that forbid the sale of any military equipment to Iraq," an official said. The same was true of the goggles and missiles, according to the Americans.

The jamming devices were initially imported to counter U.S. and British jets patrolling the "no-fly" zones of northern and southern Iraq, U.S. officials believe, citing intelligence sources, and were deployed last week when U.S. forces began their attack.

Complaints from U.S. officials escalated in recent weeks, and earlier this month Russian Ambassador Yuri Ushakov was summoned to the State Department to discuss the matter. Some of the administration's highest-ranking officials pressed the issue with their Russian counterparts.

"We know that they're turned on. We know that they're attempting to use them," the official said of the equipment. "My pilots are taking signals from these."

Administration officials became infuriated last week when they learned that Aviaconversiya personnel are now in Iraq "showing Iraqis how to use them and how to fix them," said the official. The Russians "sure as hell should have been able to stop these guys."

U.S. diplomats in Moscow protested to the Russian Foreign Ministry yesterday. The Russians, who had assured the Americans that Aviaconversiya was being closely monitored, were "clearly taken aback by the news," according to one government report.

The administration was reluctant to release information on its campaign to block the sale of the weapons and gear at a time when the White House was managing a complex agenda with the Russians -- including a bid to win approval of a nuclear weapons treaty, the effort to win Putin's help in pressuring North Korea and the failed attempt to obtain Russian support for the use of force in Iraq.

The discovery of the Aviaconversiya personnel, combined with what U.S. officials consider an imminent threat to American military forces, persuaded the administration to discuss the issue.

"The bottom line is the Russians knew about this last June," said an official. "They did nothing."