US regulator the Food and Drug Administration has banned imports from a central Indian manufacturing plant of generic drugmaker Ipca Laboratories Ltd , citing violations of standard production practices. India is second only to Canada as a pharmaceuticals exporter to the United States, where it supplies about 40 percent of generic and over-the-counter drugs. But its image as a safe, affordable supplier has suffered from a spate of regulatory sanctions over the past year aimed at large drugmakers, such as Ranbaxy Laboratories Ltd and Wockhardt Ltd, stemming from production concerns. Last July Ipca suspended shipments to the United States from the plant at Ratlam in India's central state of Madhya Pradesh that makes drug ingredients, after the FDA outlined half a dozen violations, including data integrity issues. The FDA announced the ban, called an import alert, on its website late on Thursday. It did not elaborate. Ipca is working to resolve the issue at the earliest, the company said on Friday. Four chemicals made at the Ratlam plant have been exempted from the FDA import sanction, it said in a notice to the stock exchanges. Earlier data integrity issues at Indian drug and ingredient makers have revolved around the deletion of electronic data, the concealment of data on failed tests, the fabrication of records and test repetition to ensure satisfactory results. Canada, Europe and Australia are among Ipca's other global markets. Exports accounted for about 63 percent of sales in the financial year that ended on March 31, its website shows. The company's shares were down 8.4 percent at 640 rupees by 0211 GMT on Friday, underperforming the benchmark NSE index , which was trading up 0.8 percent. ($1=61.4300 Indian rupees) (Reporting by Sumeet Chatterjee; Editing by Clarence Fernandez)"