Kohlberg Kravis Roberts will on Friday unveil plans to diversify into infrastructure, hiring a top Lazard executive to lead an expected $5bn fundraising, as the US private equity group reacts to recent credit market turmoil.

The shift into infrastructure is a tacit admission by KKR that it is too focused on “mega buy-outs” of large companies, which have become almost impossible as the debt needed to finance them has dried up in the credit squeeze.