Tenaga Nasional Bhd (TNB) is asking bankers to submit pitches for a US$3 billion (RM13 billion) sukuk programme, and proceeds will be used to fund overseas investments, including the purchase of a 30 per cent stake in Turkish power firm Gama Enerji AS for US$243 million. The company last issued dollar-denominated debt in 1996, when it sold 100-year conventional notes. Bankers’ proposals for TNB’s sukuk programme had to be submitted by the end of this week. TNB is rated “BBB+”, the third-lowest investment grade by Standard & Poor’s and Fitch Ratings. The yield on the company’s existing conventional dollar bonds due 2025 climbed 31 basis points last year to 4.39 per cent and was 4.33 per cent yesterday.