Arthur J. Gallagher has agreed to acquire AssuredPartners in a $13.45 billion deal.The insurance brokerage, risk-management and consulting-services firm said Monday that buying the insurance broker would expand its retail middle-market property and casualty focus across the U.

Gallagher plans to fund the acquisition through a mix of long-term debt, short-term borrowings, free cash and common equity.

Under the agreement, Gallagher will acquire AssuredPartners’ parent company from GTCR and funds advised by Apax Partners LLP. The net consideration for the transaction, after accounting for a $1 billion deferred tax asset, is approximately $12.45 billion, representing an EBITDAC multiple of 11.3x after synergies.