FILE PHOTO: A smartphone with Sprint logo are seen in front of a screen projection of T-mobile logo, in this picture illustration taken April 30, 2018. REUTERS/Dado Ruvic/Illustration

NEW YORK (Reuters) - Testimony ended on Friday in a lawsuit by a group of states led by New York and California seeking to block the merger of Sprint Corp and T-Mobile US Inc, moving the trial a step closer to having a U.S. judge rule on whether the deal violates federal antitrust laws.

The states and the companies now have until Jan. 8 to submit proposed factual findings in writing to U.S. District Judge Victor Marrero in Manhattan federal court. The judge scheduled closing arguments for Jan. 15.

The states filed the lawsuit in June in a bid to block the $26.5 billion merger, saying it would lead to higher prices for consumers. T-Mobile and Sprint have argued that the $26.5 billion merger would enable the combined company to compete more effectively with dominant carriers Verizon Communications Inc and AT&T Inc.

The U.S. Justice Department approved the deal in July after the carriers agreed to sell some assets to satellite provider Dish Network Corp, which would create its own cellular network to ensure that there would still be four competitors in the market. The Federal Communications Commission signed off on the deal in October.

Throughout the trial, the states argued that Dish is not a suitable company to become a fourth wireless carrier because it has not been able to build a network using the wireless spectrum, or airwaves that carry data, it already owns.

In a court filing on Friday, the Justice Department and FCC urged Marrero to rule against the states, saying that if the deal were blocked, rural areas of the United States would be slower to get access to 5G, the next generation of wireless.