LONDON, June 15 (IFR) - Holders of Co-operative bank's subordinated debt are set to receive some £27m of coupon payments in the coming weeks despite the troubled UK lender struggling to find a buyer for its business. A spokesperson for the bank confirmed that it will pay a quarterly coupon of £5.67m on a 11% Tier 2 due in December 2023 on June 20 and an annual coupon of £21.25m on a 8.5% July 2025 Tier 2 at the beginning of next month. The UK lender put itself up for sale in February after...