U.S. District Court Judge Audrey Collins issued a preliminary injunction against RMG Technologies Inc., barring the Pittsburgh, Penn.-based firm from buying or facilitating the purchase of tickets from Ticketmaster's website for the purpose of reselling them.
Collins concluded Ticketmaster would prove its claims that RMG infringed on its copyrights, violated the Digital Millennium Copyright Act and breached the website's terms of use.
"We will not allow others to illegally divert tickets away from fans," Ticketmaster chief executive Sean Moriarty said in a statement.
West Hollywood-based Ticketmaster, a leading seller of concert and sporting event tickets, sued RMG in August in federal court in Los Angeles.
The ticketing company blamed RMG's software for helping ticket scalpers scoop up prized tickets that they later sell for inflated prices.
A telephone message left with RMG was not immediately returned.
In her ruling, the judge determined that that RMG's software harms Ticketmaster and the public "because it denies consumers the opportunity to purchase tickets to events at a fair price."
Collins cited reports of complaints by fans, including many parents who were priced out of getting tickets for Disney Channel's Hannah Montana concert tour.
Ticketmaster is owned by IAC, the New York-based Internet conglomerate controlled by media mogul Barry Diller. It operates in 20 countries with 6,500 retail outlets and 20 call centres around the world.
Ticketmaster has been battling competitors in the secondary ticketing market, such as StubHub, which is growing rapidly. The success of resellers shows the primary ticket price may not have been as high as it could have been.
"We recognize and respect the necessity and reality of a vibrant resale market, but we will not tolerate those who seek an unfair advantage through the use of automated programs," Moriarty said in the statement.