Simpson Thacher & Bartlett’s corporate lawyers grabbed a spot across the negotiating table from longtime client KKR on Monday, advising private equity rival Hellman & Friedman on the $2.3 billion sale of insurance claims processor Sedgwick Claims Management Services.

It’s the second major insurance industry acquisition for KKR in five months. The Am Law Daily reported in September on Simpson’s role advising KKR on its $1.1 billion buy of property claims software company Mitchell International from private equity firm Aurora Capital Group.