WASHINGTON, Feb 6 (Reuters) - The U.S. Transportation Department said on Wednesday it would quickly replace baggage and passenger screening run by Argenbright Security if the embattled firm failed to meet post-Sept. 11 standards for airport security. John Magaw, ???Transportation Security Administration, briefed members of Congress on the agency's plans for taking over screening contracts from the airlines on Feb. 17. Those contracts expire next November when the security admininstration will take over screening operations at 429 U.S. airports. The TSA will employ between 30,000 and 40,000 screeners and other security personnel and has a proposed budget for next year of $4.8 billion. While the Transportation Department is refusing to contract directly with Argenbright, the company will still perform screening work at numerous U.S. airports under the extension of existing agreements with airlines. The government will reimburse those carriers who have their own contracts with Argenbright. "Where Argenbright has an existing contract we are going to look at that performance quickly. If we see that they are not measuring up then we would replace it," Magaw told members of the House of Representatives appropriations subcommittee on aviation. Atlanta-based Argenbright, a unit of British-owned Securicor Plc (SCR), pledged to work for a smooth transition to a federal screening workforce. The company has had several high-profile security lapses in addition to a criminal case in Philadelphia over its hiring practices. Argenbright also operated the screening checkpoint at San Francicso International Airport, where an apparent security mix-up last week prompted the evacuation of thousands of people from the United Airlines concourse. The company employs 6,000 screeners and controls 40 percent of passenger and baggage screening services at airports nationwide. The State Department has proposed that Argenbright be barred from signing any federal contracts because of alleged problems the firm had with that agency. But the Transportation Department could have done business with it anyway, if the agency had found doing so was in the public interest. Transportation Secretary Norman Mineta has elected not to sign any contracts with Argenbright, which submitted no bids for the work, a company spokeswoman said. Bids were due on Wednesday. David Beaton, Argenbright's chief executive, said in a statement that Mineta's decision to not contract directly with the firm was not surprising nor significant since private screening companies will all be replaced by the end of the year anyway. "We believe the DOT's decision, which we understand was based on the State Department's proposed debarment, is unnecessary but we want to do everything possible to cooperate and minimize disruption to airlines and their customers," Beaton said.