Vodafone Group chief executive Arun Sarin can breath a small sigh of relief before the company's shareholder meeting tomorrow, but he's sure to face institutional investors keen on voting down his re-election. The world's largest operator said its subscriber base grew 9.5 percent at the end of June, assisted primarily by its purchase of Turkish carrier Telsim. Vodafone said it added 4.5 million proportionate customers, with another 11.7 million coming from its full control of Telsim in Turkey. The operator ended June with 186.6 million customers, with the group's total 3G device base now at 9.1 million. The biggest struggle right now is how Vodafone will compete in the saturated European market. Its European properties are facing intense completion and increased churn, and Sarin has been criticized as he navigates Vodafone through these challenges. It didn't help that Bill Morrow, recently tapped to head Vodafone's European operations, is leaving at the end of the month, citing family reasons. Sarin will likely now face new questions on the company's European strategy at the shareholder meeting tomorrow, as well as criticism from stockholders. Last week it was revealed that Morley Fund Management, which owns a 2.1 percent stake in Vodafone, is planning to vote against Sarin's re-election to the board. Other institutional investors will reportedly vote against his re-election as well.