Arthur J. Gallagher & Co. (AJG), a prominent firm in insurance brokerage, risk management, and consulting, announced on Monday a public offering of shares valued at $8.5 billion. Additionally, Gallagher plans to provide the underwriters with a 30-day option to acquire an extra $1.275 billion in shares. The company aims to utilize the net proceeds from this offering to finance its intended acquisition of Dolphin TopCo, Inc., as well as for general corporate purposes.