Sabre Sells Trams Back to Lee Rosen and Tres Technologies TRAMS Founder Lee Rosen. Sabre this week announced that it was selling the Trams portfolio of products to Tres Technologies and its president Lee Rosen. Rosen, the original owner of Trams, and the team at Tres will now take Trams back from Sabre as the GDS provider continues to work toward creating “a new marketplace for personalized travel.” “While the Trams portfolio is an important part of helping travel agencies respond to the industry’s change and evolution, Sabre believes that Tres is better suited to lead the evolution in this area while we are focused on our strategic imperatives that will transform the way the industry retails, distributes, and fulfills travel,” Sabre said in a message to its users.