Kohlberg Kravis Roberts has received the lion's share of its equity investment in Alliance Boots back after the sale of a 45% stake in the UK-based chemist chain to US drug store Walgreen for $6.7bn.

The US buyout firm, which invested £1.2bn in the company in 2007 - in what remains Europe's largest-ever leveraged buyout at £11.1bn - has received £1.2bn back in the deal, announced this morning. Walgreen will also have the option to buy the rest of the shares in the future.