Nokia will pay 1.7 billion euros for the stake. This comes as NSN starts to show profits following a series of cost cutting exercises.
The company hopes that with its complete takeover of NSN, which makes telecom network equipment, it can expand its reach into major growth areas including broadband technology.
"Nokia Siemens Networks has established a clear leadership position in LTE, which provides an attractive growth opportunity," Nokia chief executive Stephen Elop said in a statement. "Nokia is pleased with these developments and looks forward to continue supporting these efforts to create more shareholder value for the Nokia group.”
The joint venture was launched in 2007 but struggled to make profits in the early years. However, NSN introduced cost cutting measures and in November 2011 announced 17,000 job cuts, which accounted for 23 percent of its workforce.