Wireless telecom operator Vodafone Group was upgraded to outperform from underperform at Exane BNP Paribas on Tuesday. The broker said it expects European top line to improve progressively and fiscal 2011 guidance should prove supportive on margins. In addition, it said two catalysts may emerge "sooner rather than later." The first is the return of a dividend at its Verizon Wireless joint venture. Secondly, the sale of the firm's stake in SFR "seems a real possibility," it added. Shares were flat in London.