By John Crawley WASHINGTON, Feb 13 (Reuters) - The Transportation Department plans to replace all Argenbright Security units at U.S. airports within several weeks of taking over baggage and passenger screening contracts from the airlines next week following security breaches after the Sept. 11 attacks, a senior agency official said on Thursday. Deputy Transportation Secretary Michael Jackson told reporters at a security briefing that the department hoped to sign contracts in coming days with other screening companies who would replace Argenbright within six weeks. The agency is wrapping up agreements with 60 airline security firms and certain airlines for temporary screening until they are replaced by a federal work force at more than 400 airports. The government takes over the contracts on Sunday and will begin placing federal screeners at airports beginning in May. Congress has ordered the Transportation Department to have its screening corps of about 30,000 workers fully in place by November. A unit of British-owned Securicor Plc (SCR), Atlanta-based Argenbright holds about 40 percent of the screening market domestically. It has had a number of high-profile security lapses in addition to a criminal case in Philadelphia in recent years over its hiring practices. Argenbright lost its contract last year at Boston's Logan airport. Argenbright screeners allowed a man carrying knives, a stun gun and tear gas through a checkpoint at Chicago's O'Hare International Airport in November. Last month an Argenbright screener caused panic at San Francisco International Airport by allowing a man whose shoes tested positive for possible explosive residue to wander off, causing thousands of passengers to be evacuated. ARGENBRIGHT PLEDGES COOPERATION The Transportation Department is refusing to deal directly with the company for screening services during the transition to a federal work force. Instead, it will contract with airlines and airports that already have agreements with Argenbright. "We expect Argenbright to be replaced at all of the screening locations where they are currently serving," Jackson said. He said the speed at which Argenbright is replaced will vary from airport to airport. Agency officials also said Argenbright employees may be retained by replacement companies and some could even move into federal jobs, if they apply for them and meet the standards. Argenbright, which is the sole screening contractor at Dulles in Northern Virginia, Denver International Airport and a several other airports nationally, has pledged to cooperate with the government. "During this period of transition, Argenbright is ready and prepared to work with the (Transportation Department) and aviation officials to ensure the safety and convenience of the flying public," a company statement said. Jackson did not give a dollar figure for the interim screening contracts but said the government would pay more than the airlines did for the same services. "This is a reflection of the fact that these businesses will no longer be serving this marketplace," Jackson said. "We are having to grapple with that economic reality. We hope they will have a fair price for us and we expect they will."