The rating on leading Turkish mobile telecommunications group Turkcell Iletisim Hizmetleri A.S. is underpinned by the company's strong performance in the dynamic Turkish mobile telephony market, good cash flow generation, and low financial leverage. Rating constraints are the volatile Turkish macroeconomic environment, potential currency swings, international expansion in Ukraine, and continuing legal disputes among the group's major shareholders. At Sept. 30, 2007, Turkcell had $740 million in consolidated on-balance-sheet debt. Turkcell's share of subscribers in the Turkish market stood at 57% as of Sept. 30, 2007. Competitors, including Vodafone Group PLC (A-/Stable/A-2), have eroded the operator's market share, but only to a limited extent; Turkcell's share was 64% at year-end 2005. Steady increases in market penetration, sustained subscriber growth, rising