As the government prepared for war in Iraq in the fall of 2002, a senior political appointee in the Defense Department chose oil services giant Halliburton Co. to secretly plan how to repair Iraqi oil fields, and then briefed Vice President Cheney's chief of staff and other White House officials about the sole-source contract before it was granted.

Rep. Henry A. Waxman (D-Calif.) said the new details about the $1.8 million contract, disclosed last week in a Pentagon briefing for congressional staff members, raise new questions about whether the vice president or his office played any role in decisions to give what became billions of dollars worth of government business to Halliburton, where Cheney was chief executive from 1995 to 2000.

Cheney has said neither he nor his office influenced decisions to give contracts to Halliburton.

In a letter to Cheney yesterday, Waxman said the circumstances "appear to contradict your assertions that you were not informed about the Halliburton contracts."

"They also seem to contradict the Administration's repeated assertions that political appointees were not involved in the award of contracts to Halliburton," wrote Waxman, senior Democrat on the House Government Reform Committee and one of the sharpest critics of the government's ties to Halliburton.

Kevin Kellems, a spokesman for Cheney, played down the importance of Waxman's letter, suggesting it was politically motivated. "We stand by our previous statements," Kellems said.

The letter describes a briefing at which Michael H. Mobbs, a political appointee who works closely with undersecretary of defense Douglas J. Feith, acknowledged that he selected Halliburton for Iraq reconstruction work. Mobbs that he believed Halliburton's KBR subsidiary was most qualified, in part because it was familiar with plans under development by U.S. Central Command, the letter said.

Before making a final decision, Mobbs briefed top officials from several executive agencies, in a group known as the Deputies Committee, to ensure they had no objections. Among those at the meeting were Lewis "Scooter" Libby, Cheney's top aide, and White House staff members. After that meeting, Waxman's letter says, a White House official told Feith the group did not object.

A career lawyer from the Army Materiel Command, responsible for another contract with Halliburton for meals and laundry services, said that arrangement should not be expanded to include contingency planning for Iraq's oil infrastructure. "These legal reservations were overruled, however," in part because a Defense Department attorney working with Mobbs intervened, according to Waxman's letter.

Kellems said neither Cheney nor Libby had read Waxman's letter.

Waxman also raised questions about a March 5, 2003, e-mail by an Army Corps of Engineers official that suggested a larger no-bid contract to Halliburton subsidiary was "coordinated" with Cheney's office. Stephen Browning, a civilian regional director in the Corps, said in an interview last week that he wrote the note after he and retired Lt. Gen. Jay M. Garner met with Feith about plans to declassify the earlier $1.8 million contract with KBR.

According to Browning, Feith said he had already informed Cheney's office. Three days later, KBR got a $7 billion contract to restore Iraq's oil infrastructure. The war began March 20, 2003. At the briefing last week, Browning repeated his story, Waxman's letter said.

"These disclosures mean that your office was informed about the Halliburton contracts at least twice at key moments," Waxman wrote.

Waxman asked Cheney to "clarify the nature of your involvements" in the contract awards.

Rep. Henry A. Waxman (D-Calif.) sent a letter to Vice President Cheney.