Strong investor demand and a need to improve capital adequacy ratios are causing Turkey's Islamic banks to consider issuing subordinated sukuk. Ibrahim Oguducu, head of the financial institutions business at Bank Asya, said longer-tenor subordinated sukuk would help balance mismatches between the maturities of banks' liabilities and assets, while diversifying their funding sources. Subordinated issues might not be expensive for Turkey's Islamic banks that have issued only two sukuk so far.