Online entertainment ticket retailer Ticketmaster has won a court victory in its ongoing legal dispute with Costa Mesa-based Tickets.com.

A three-judge panel of the 9th Circuit Court of Appeals on Monday affirmed a 2003 decision by a federal judge dismissing a counterclaim Tickets.com filed against Ticketmaster in its long-running contract dispute.

Ticketmaster, a West Hollywood division of IAC/InterActive Corp., originally filed suit against the smaller firm for breach of contract and copyright violation, alleging it took proprietary information about entertainment events from its Web site for use on its own site.

In 2000, a federal judge dismissed much of Ticketmaster’s suit, and Ticketmaster did not pursue the remaining claims. But in a subsequent counterclaim, Tickets.com accused Ticketmaster of violating federal anti-trust laws because of the average, roughly six-year length of Ticketmaster’s contracts, according to court documents.

“Tickets.com’s basic theory was that the exclusive contracts were too long to allow it to compete, and the 9th Circuit said, ‘No, there was ample opportunity to compete with contracts,'” said Steven Sletten, a partner at Gibson Dunn & Crutcher LLP representing Ticketmaster.