A federal judge on Tuesday approved the merger of Sprint and T-Mobile, US media reported, clearing the way for the number three and four US mobile phone companies to combine. Federal Communications Commission Chairman Ajit Pai, who has backed the deal, applauded a ruling from US District Judge Victor Marrero that held the combination would not significantly harm competition. "The T-Mobile-Sprint merger will help close the digital divide and secure United States leadership in 5G," said Pai, pointing to a pledge from T-Mobile to expand telecom services to rural areas in the United States. Critics had lambasted the deal and said the removal of a leading provider would ultimately lead to higher prices. Backers of the deal said combining T-Mobile and Sprint will create a strong number three US wireless carrier behind Verizon and AT&T, with the resources to invest in 5G, or fifth-generation, networks. Shares of Sprint surged 75.4 percent to $8.42 in pre-market trading, while T-Mobile jumped 9.7 percent to $92.75. vog-jmb/cs