Sen. Joseph Lieberman (search), a Democratic presidential contender, asked the Pentagon on Tuesday to consider barring Vice President Dick Cheney's former company from future government contracts after an audit showing Halliburton (search) may have overcharged for fuel in Iraq.

Lieberman, D-Conn. wrote Defense Secretary Donald H. Rumsfeld that federal contractors are required under the law to have "a satisfactory record of integrity and business ethics."

"Based on current and past allegations against Halliburton, there needs to be a careful review of whether the company has complied with this important requirement," Lieberman wrote.

The Pentagon said in a statement that "DOD is conducting a careful review of a number of contracts. This is an ongoing process initiated by DOD and of course includes KBR," Halliburton's oil services subsidiary.

Halliburton has consistently denied overcharges on a U.S. government contract to bring oil to Iraqis from nearby countries.

Last week, a Pentagon audit found KBR may have overcharged the Army $1.09 per gallon for nearly 57 million gallons of gasoline delivered to Iraq.

Lieberman, senior Democrat on the Senate Governmental Affairs Committee, asked Rumsfeld to "evaluate whether Halliburton should be considered for suspension or debarment proceedings, which could prevent the company from bidding on any federal contracts for a number of years."

Several Democratic lawmakers and presidential candidates have criticized KBR's oil services contract with the Army Corps of Engineers, work that has grown without competitive bidding.

In 2002, Halliburton agreed to pay $2 million in fines to settle fraud charges alleging that it inflated prices when performing repair and maintenance work for the military at Fort Ord, Calif. The General Accounting Office also found evidence in 1997 and 2000 that Halliburton engaged in questionable billing practices for work it performed for the Army in the Balkans.