skyrocketed 49.4% Wednesday, a day after the company said its biggest customer,
, agreed to dismiss a demand for arbitration with the company.
The company's shares were recently up $13.94 to $42.
Last month, AT&T sought arbitration, claiming that CSG violated the terms of the agreement between the companies, causing shares of CSG to plummet. AT&T alleged that CSG failed to fulfill its obligations for telephone software and services.
Yesterday, the companies agreed to amend their contract in a way they believe is "mutually beneficial."