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 maturing Turkish mobile telephony market, good cash flow generation, and conservative balance sheet. Astelit, Turkcell's 55%-owned subsidiary operating in the well-supplied and economically challenged Ukrainian market, remains a source of credit risk, currently concentrates the bulk of the group's debt, and still burns cash. Standard&Poor's Ratings Services expects a similar cash flow and business profile for Turkcell's recently acquired, 80%-owned Belarusian subsidiary BeST. Turkcell's 41.5%-owned associate Fintur Holdings B.V., on the other