Shares in Wockhardt Ltd plummeted as much as 19.3 percent on Friday to their lowest since August 2012, continuing to reel for the second day, after the U.S. Food and Drug Administration imposed an "import alert" on a plant operated by the generic drugmaker.
Wockhardt shares had already slumped by their daily limit of 20 percent on Thursday on the U.S. FDA action.
An "import alert", effectively a ban, results in detention without physical examination of drugs from firms that have not met so-called good manufacturing practices, according to the FDA website.
Wockhardt said the FDA's action potentially affects $100 million in revenue on an annualised basis, but said it should be able to restore most of that within 6 to 9 months by shifting production to other facilities.
Wockhardt shares ended with losses of 6 percent.