The U.S. Federal Communications Commission gave the green light for the $21.6 billion purchase of Sprint Nextel by Japanese telecom firm SoftBank, saying the deal was in the "public interest."

"Today is a good day for all Americans who use mobile broadband services. After thorough review, the Commission has found that the proposed SoftBank-Sprint-Clearwire transactions would serve the public interest," FCC chairwoman Mignon Clyburn said Friday in a statement.

The FCC cleared the way for SoftBank to acquire 78 percent of the United States' third-largest U.S. wireless operator.

The purchase price was raised from a previous amount of $20.1 billion amid a counter offer by satellite TV operator Dish Network.

U.S. authorities also approved Sprint's plan to purchase the shares it did not already own in mobile broadband network Clearwire, which will allow it to expand its wireless spectrum holdings and strengthen its competitive position with respect to the two market leaders, Verizon and AT&T.

"Just two years ago, the wireless industry was at the doorstep of duopoly, but with these transformative transactions, we are one step closer to a stronger Sprint which will better serve consumers, challenge the market share leaders and drive innovation in the American economy," Sprint CEO Dan Hesse said in praising the FCC's decision.

Sprint shareholders voted last week to approve the deal, one of the biggest-ever foreign investments by a Japanese company.

"SoftBank's investment in Sprint will bring innovation and increased customer focus, which will enable us to begin creating a true competitor in a market dominated by two companies," SoftBank Chairman & CEO Masayoshi Son said. EFE