NEW YORK (CNN/Money) - A software engineer at America Online was arrested Wednesday and charged with stealing AOL's subscriber list and selling it to someone sending spam e-mail, federal prosecutors in New York said.

According to the criminal complaint, Jason Smathers of Harpers Ferry, W. Va., used his inside knowledge of AOL's computer system to steal a list of 92 million AOL customer account "screen names," and then sold them to Sean Dunaway, who is not an AOL employee.

Dunaway, of Las Vegas, NV., was accused of using the list to promote his own Internet gambling business and also sold the list to other spammers for $52,000, according to David Kelley, the U.S. attorney for the Southern District of New York.

The complaint further charges that Dunaway later paid Smathers $100,000 for an updated version of AOL's customer list.

Megan Gaffney, a spokeswoman with the U.S. Attorney's Office, Southern District of New York, confirmed that both men appeared in court Wednesday.

Dunaway, 21, attended federal court in Las Vegas, and Smathers, 24, made his initial federal court appearance in Virginia. Smathers will be detained overnight until a detention hearing tomorrow, Gaffney said.

Defense lawyers could not be reached for comment.

The two men each face a maximum sentence of five years in prison and a fine of $250,000, according to prosecutors.

An AOL spokesman said Smathers has been fired from the company.

"We deeply regret what has taken place and are thoroughly reviewing and strengthening our internal procedures as a result of this investigation and arrest," AOL said in a statement.

According to the complaint, Smathers used another employee's ID in April and May 2003 to assemble a complete list of AOL's customer account screen names, zip codes, telephone numbers and credit card types.

"(But) AOL has uncovered no information indicating that this theft involved member credit card or password information stored by AOL," said the statement from AOL.

AOL, the world's biggest Internet service provider, is owned by Time Warner Inc., as is CNN/Money.