Alliance Boots (LSE: AB.L - news) today confirmed that it has received an improved £10bn bid proposal from Kohlberg Kravis (Advertisement). The chemist chain and drugs wholesaler, which previously rejected a 1,000p share offer, or just under £10bn, from Kohlberg Kravis Roberts, said it was now looking at a 1,040p cash offer from KKR and Pessina. "The Board has agreed to grant Kohlberg Kravis Roberts and Stefano Pessina a limited period to undertake confirmatory due diligence. A further announcement will be made as and when appropriate." Pessina was chief executive at Alliance Unichem for three years until the end of 2004 and the executive deputy chairman when it merged with Boots in a nil-premium deal last year. He has previously said that his objective is to work closely with the existing executive management team to achieve the long-term vision of building a global leader in the healthcare services and beauty industries.