The pace of M&A activity throughout the insurance industry accelerated year over year during the first half of 2021, according to an S&P Global Market Intelligence analysis.

There were a total of 453 insurance deals announced during the period, compared to 400 in the first half of 2020, the analysis found.

There were 375 deals in the insurance brokerage space during the first half of the year, up from 331 transactions in the six months through June 30, 2020. Insurance underwriters saw nine more transactions than there were in the prior-year period.

The largest deal announced during the first half of 2021 was Arthur J. Gallagher & Co.'s planned acquisition of Willis Re and other Willis Towers Watson PLC assets for $3.57 billion. The transaction is subject to the completion of the pending merger between Aon PLC and Willis Towers Watson and regulatory approval, as well as other customary closing conditions.

During the second quarter, M&A activity in the property and casualty and multiline sectors was up, rising to 16 deals from 13 in the prior-year period.

The life and health space recorded eight deals in the second quarter, compared with seven in the second quarter of 2020. Managed care transaction activity edged down, with four deals in the quarter versus six a year earlier.