SINGAPORE (BLOOMBERG) - Jardine Matheson Holdings group stocks have turned from some of Singapore's best performers to the worst this year amid a resurgence of coronavirus infections in South-east Asia.

Shares of the venerable trading firm, which gets more than half of its annual revenue from South-east Asia, dropped 8.6 per cent last month, ranking it among the worst performers on the Straits Times Index. Concerns over the Delta variant have punctuated a stark turnaround for the stock, which had surged 25 per cent in March on a restructuring plan.

Jardine group shares listed in Singapore lost a combined market value of about US$5 billion (S$6.7 billion) last month, according to data compiled by Bloomberg. The slide marks a return to the losses of last year amid the global pandemic sell-off.

Supermarket operator Dairy Farm International Holdings, which owns Giant and Cold Storage, is the top loser among the Jardine group's Singapore-listed stocks to date this year, down 15 per cent. Other Jardine holdings that suffered hits last month include property firm Hongkong Land Holdings and Jardine Cycle & Carriage.

"The expectation is that raging infections and restrictions in South-east Asian economies will weigh on Jardine group businesses," said Mr Justin Tang, head of Asian research at United First Partners in Singapore.