Constraining the rating on leading Turkish mobile telecommunications group Turkcell Iletisim Hizmetleri A.S. are the volatile Turkish macroeconomic environment, potential currency swings, international expansion in Ukraine and Belarus, and continuing legal disputes among the group's major shareholders. Supportive factors include the company's strong performance in the dynamic but gradually maturing Turkish mobile telephony market, good cash flow generation, and conservative balance sheet. Competitors, including Vodafone Group PLC (A-/Stable/A-2), have only eroded Turkcell's market share to a limited extent (it was 56% at Sept. 30, 2008, compared with 60% at year-end 2006). Sustained subscriber growth and rising usage on Turkcell's network and in post-paid subscriber numbers have supported local currency average revenue per user (ARPU), which was up 4%, year on
