The Texas attorney general had asked the court to grant a summary judgment that the maps approved this year by the Legislature were fair and could be used in the 2012 election. Opponents argued that the maps were discriminatory against minority groups and asked the court for a full hearing of their arguments.
The three-judge panel agreed on Tuesday and ordered both sides to prepare arguments.
The case is separate from another suit filed in a San Antonio federal court. Judges there are considering an interim map for the 2012 election.