The office of California Attorney-General Xavier Becerra said it was reviewing the court ruling and its options.
The 11 other states in the group and the District of Columbia did not immediately reply to requests for comment. Other states have also stopped pursuing their fight by focusing on jobs they were promised. In October, Colorado became the second state, after Mississippi, to drop its legal challenge after striking an agreement with T-Mobile and Dish Network Corp., which will buy the assets divested from the merger.