DuPont said on Tuesday it terminated its $5.2 billion acquisition of Rogers, a U.S. electronic materials maker, because of protracted delays in securing regulatory approval, marking the first major U.S. deal in four years to collapse because Chinese officials dragged their feet on providing clearance. Qualcomm ended its $44 billion purchase of Dutch peer NXP Semiconductors NV in 2018 after failing to secure regulatory approval.

China's regulators have declined to comment on the DuPont deal and have not provided a reason for the delay in reviewing it. But the deal's demise comes amid renewed trade and geopolitical tensions between Washington and Beijing that has fueled investor concerns that mergers could become a casualty.

One merger arbitrage fund investor, who declined to be named, said deals involving Chinese approval will be closely watched in the aftermath of the scrapped DuPont-Rogers deal.

Shares of some U.S. companies with a significant footprint in China that are waiting to complete deals dropped on Wednesday as a result.

Shares of Tower Semiconductor, which agreed in February to sell itself to Intel Corp for $5.4 billion, were down 4% on Wednesday afternoon at $41.31, a significant discount to the $53 per share deal price, reflecting doubt among investors over whether the transaction will be completed.

Shares of Altra Industrial Motion Corp, a U.S. automation equipment maker which agreed last week to sell itself to Regal Rexnord Corp for $5 billion, traded down almost 1% to $59.19, their biggest discount to the $62-per-share deal price since the transaction was announced.

Shares of U.S. chip maker Silicon Motion Technology Corp, which will require Chinese regulatory approval to complete its $3.8 billion sale to peer MaxLinear Inc, have dropped 40% since their transaction was announced in May.

Some investors cautioned, however, that the collapse of these deals hinges not just on whether Chinese regulators will withhold clearance but also on whether the acquirers are committed to the transactions.

In the case of Rogers, DuPont was happy to walk away rather than give the Chinese regulators more time because this year's market downturn had made the acquisition seem pricey compared to when it inked the deal 12 months ago, experts said.

"Investors felt that DuPont was paying too much for Rogers and there were expectations of a price cut," said Chris Pultz, portfolio manager for merger arbitrage at Kellner Capital.

(Editing by Deepa Babington)

By Anirban Sen