Richard Baker, chief executive of Alliance Boots, has left the high street chemist following a management shake up by its new private equity owners Kohlberg Kravis Roberts.

The former Asda chief operating officer had elected to pursue his career elsewhere, KKR said.

Baker joined Asda in July 1995 as business unit director and also held the roles of deputy trading director, group marketing director and chief operating officer before leaving the supermarket chain in May 2003 to take the CEO role at Boots.