DULUTH, Minn. — The nation's largest record companies took their fight against illegal downloads to a jury for the first time yesterday, targeting a Minnesota woman they say improperly shared nearly 2,000 songs online.

Jammie Thomas, a 30-year-old mother of two from Brainerd, Minn., said outside the federal courtroom where the civil copyright trial is unfolding that she did nothing wrong.

"I do know that I didn't do this, and the jury will hear that I did not do this," she said.

Thomas said that instead of paying a settlement to the six record companies that sued her, she chose to spend the same amount on her attorney's retainer.

"I refuse to be bullied," she said.

Jennifer Pariser, head of litigation and anti-piracy at Sony BMG, portrayed the trial as a fight for survival.

"It is imperative for Sony BMG to combat this problem," Pariser testified under questioning from Richard Gabriel, who is lead counsel for the record companies. "If we don't, we have no business anymore."

Thomas' attorney, Brian Toder, said Thomas was "in the position of trying to prove some alternative theory when she doesn't know what happened out there."

"We're in the position of trying to prove a negative, and we can't do it," he told the jury. Later, he said: "You're not going to see evidence that she distributed anything."

Music sales have slumped in recent years as more people have turned to file-sharing. The recording industry has filed thousands of complaints over alleged music piracy, but the action against Thomas is the first to get to trial because most defendants have settled by paying a few thousand dollars.

The trial was expected to last just a few days.

The record companies accuse Thomas of making 1,702 songs available on her Kazaa file-sharing account in 2005 without permission. In court, they will try to prove Thomas shared 25 specific songs in violation of copyrights the companies hold.

Thomas' computer hard drive will be a key to the case. She says she replaced it after she had some computer problems in 2005. The record companies say she was trying to cover her tracks after they sent her messages saying she was illegally distributing their files.

Thomas, who works for the Department of Natural Resources of the Mille Lacs Band of Ojibwe, is at risk for a judgment of more than $1.2 million. The recording association is seeking damages set under federal law, of $750 to $30,000 for each copyright violation.

As well as Sony BMG, the companies that sued Thomas are Arista Records LLC, Interscope Records, UMG Recordings Inc., Capitol Records Inc. and Warner Bros. Records Inc.

The Recording Industry Association of America, which is not a party to the lawsuit, says record companies have brought more than 26,000 actions against people alleging they shared files in violation of copyrights.

The record companies say that on Feb. 21, 2005, online investigators at SafeNet Inc. found 1,702 files had been shared under what they said was a Kazaa account being used by Thomas. The songs included Swedish death metal band Opeth, German industrial group VNV Nation and American rock band Chevelle.

"This individual was distributing these audio files for free over the Internet under the username 'tereastarrKaZaA' to potentially millions of other KaZaA users," according to court papers.

There have been no claims that Thomas' two children, ages 11 and 13, were involved in sharing music.