Dealmakers announced the biggest merger Monday of the year despite coronavirus fears and geopolitical spats upending stock, oil and debt markets.

With more than $43 billion in fresh deals announced March 9, it was the busiest Monday for transactions so far this year, and the largest since November 2019, according to data compiled by Bloomberg.

For some executives, the market rout may add to the urgency to combine with rivals to squeeze out costs to face a potential downturn. Aon Plc agreed to buy rival Willis Towers Watson Plc in a transaction worth almost $30 billion -- the largest merger announced in 2020.

The all-stock deal between the second- and third-biggest insurance brokerages will boost earnings and result in about $800 million in annual cost savings eventually, the companies said. The financial benefits could make the deal a good defensive move in a time of deep uncertainty.

Separately, Tesco Plc, Britain’s largest supermarket chain, agreed to sell its Asian businesses for more than $10 billion to Thai billionaire Dhanin Chearavanont. It’s the biggest deal in Asia this year and the biggest merger in Thailand on record, the Bloomberg data show.

Monday’s announcements helped soften the the downturn in global deals so far this year, which has seen volumes fall to $563 billion, a decrease of about 9% from the same period a year ago. That comes amid growing fears that the proliferation of the virus and its impact on economic growth, markets and travel threatens a decade-long boom in mergers and acquisitions.

This article was provided by Bloomberg News.