Kohlberg Kravis Roberts, the US private equity firm, faces making little money from an eight-year investment in insurance group Alea Holdings after its shares dropped almost 16% following a credit alert from ratings agency AM Best. KKR owns 39.4% of Alea.

KKR's purchase price and investment is about $345m. The dollar equivalent of its Alea stake and the money it took out when the insurance group was floated in 2003, is $360m.