Investment banks are poised to agree a plan to sell much of the £9bn debt in Alliance Boots, the private equity-owned pharmacy chain, providing a crucial test of improving conditions in loan markets. A group of eight banks has been holding the Alliance Boots debt since underwriting last summer’s £11bn buy-out by KKR in Europe’s biggest ever private equity deal. Deutsche Bank aims to secure approval from the other banks as early as next week for a plan to start selling the debt. It has received expressions of interest from hundreds of investors, including private equity, sovereign wealth funds and money managers.