Magic Circle firms Slaughter and May and Linklaters have landed lead roles on the biggest-ever insurance deal in southeast Asia.

Hong Kong-based FWD Group Financial Services Pte. Ltd., an insurer backed by tycoon Richard Li, the youngest son of Hong Kong’s richest person Li Ka-shing, is acquiring SCB Life Assurance Public Co. Ltd., the life insurance business of Thai lender Siam Commercial Bank Public Co. Ltd., for $3 billion, the largest-ever transaction in the industry in southeast Asia.