Crisis-hit Sri Lanka's stock exchange halted again Monday after a nearly 13-percent plunge.

The island nation is grappling with its worst economic downturn since independence in 1948, with months of regular blackouts and shortages of food and fuel.

Equities have shed nearly 40 percent of their value since January, with the local currency falling by a similar amount against the greenback in the past month.

Monday was the first morning of trade on the Colombo bourse since a week-long Sri Lankan New Year holiday and a subsequent five-day trading halt.

The local S&P index fell by 7 percent in the opening minute of trade, more than the 5 percent needed to trigger an automatic half-hour halt.

Shares continued their rapid slide after a brief resumption, prompting the market to declare a halt to trading for the rest of the day.

Read more: What has caused Sri Lanka's economic crisis?

(With input from AFP)