Three former United Express employees at Dulles International Airport have been indicted on embezzlement charges and a fourth is being sought after allegedly issuing what a company spokesman said yesterday were hundreds of fake airline tickets worth up to $1 million.

The four former employees, who worked in customer service and baggage handling, used some of the tickets for their own travel, gave others to family and friends and sold the rest for cash, said a spokesman for Atlantic Coast Airlines, which operates United Express. None of the tickets were sold to the general public, he said.

The scam began early this year, and the suspects issued tickets for domestic and international flights on United Express, United Airlines and possibly other carriers as well, the company spokesman said. Because airline tickets often sell for less than full value, the tickets were most most likely worth "hundreds of thousands" of dollars rather than $1 million, he said.

Internal auditors at United Express were alerted to a possible fraud when they noticed that a significant number of first-class and other high-end tickets were being issued by personnel who were not usually involved in sales, the spokesman said.

The suspicion grew when auditors noticed that the tickets were issued without standard authorization and redeemed in what he said was an "irregular" fashion. The company did not detail the irregularities. The practice continued while investigators conducted their probe, identifying suspicious tickets and interviewing travelers who tried to use them.

The investigation was eventually turned over to the police force of the Metropolitan Washington Airports Authority, which issued arrest warrants in June, airport authority officials said.

"What was determined through our investigation was that the employees were illegally issuing tickets for their own use and tickets they sold to others," said authority spokeswoman Tara Hamilton.

Among those named in the indictment handed up by a Loudoun County grand jury this month was Khurram Jamil, 21, of Alexandria, charged with three counts of embezzlement. Tickets he fraudulently obtained included some for a round trip to Miami, according to a criminal complaint filed in the case.

Also named were Andrea M. Hernandez, 22, of Silver Spring, and Sabenna E. Gill, 21, of Adelphi, each charged with one count of embezzlement, according to Loudoun authorities. A warrant was issued for Carlos Augusto Ramirez, 21, of Silver Spring, when he failed to show up for a June 23 hearing. Ramirez is also charged with one count of embezzlement

Hernandez is scheduled to enter a plea in Loudoun County Circuit Court on Sept. 20, according to court records. Jamil and Gill are scheduled to appear in court in October.

Embezzlement carries a maximum sentence of 20 years in prison and a $2,500 fine.

Staff writer Allan Lengel contributed to this report.