Nokia said Wednesday that its attempt to buy a majority of Symbian, the cell phone software joint venture competing with Microsoft, has been approved by a German competition authority, thus completing a "formal clearance process." Competition regulators in Finland and Austria previously gave a nod of approval for Symbian smart phone operating system creator Psion to sell its 31 percent Symbian stake to Nokia. According to Nokia, the Federal Cartel Office said the "transaction would not restrict effective competition on the wireless OS market." The office is an independent German authority that protects competition. Read more: CNet News.