Domestic pharma company IPCA Laboratories Ltd said the U.S. Food and Drug Administration issued it a warning letter outlining manufacturing quality lapses observed at three of its Indian factories, pushing its shares down as much as 16 percent. The letter concerns the company’s finished-drug plants at Piparia in western India, and Indore in central India, as well as the drug ingredients facility at Ratlam in central India, IPCA said in a statement. The plants have already been banned from supplying to the United States after the FDA inspected them in July 2014, January 2015 and March 2015, and first highlighted the lapses. IPCA said it has since been trying to fix the problems and has been informing the FDA of its remedial measures. “The company is fully committed to resolving these issues at the earliest,” it said, without disclosing the content of the letter. The FDA usually posts such letters on its website a week after issuing them to manufacturers, who need to respond to the agency within 15 days with a plan on how they would work on fixing the issues. IPCA, a mid-sized Indian firm with 2015 revenue of about $500 million, has 16 manufacturing plants in India from where it supplies to more than 120 countries. The three sites with U.S. bans also supply to India, UK and Canada. The FDA warning follows similar action on plants of larger rivals Dr Reddy’s Laboratories Ltd and Sun Pharmaceutical Industries Ltd in November and December, respectively. Several drug factories in India have been cited by the FDA over the last two years for violating manufacturing quality standards, as the FDA has increased its oversight of the industry, which is a key supplier to the United States. Intra-day, IPCA stock tanked as much as 16 percent before recovering majority of its losses to trade 2.4 percent lower at Rs 652.35 at 2.45 pm on BSE.