(Adds detail, background, shares)
June 4 (Reuters) - HeartWare International Inc said it received a warning letter from the U.S. Food and Drug Administration following an inspection of its manufacturing plant in Florida in January.
The company said the FDA had not restricted the use of its miniature implantable heart pumps used to help patients suffering from advanced heart failure.
The agency cited problems with the company's procedures to validate device design, including labeling.
Medical device makers are required to conduct tests to determine whether their products are inducing the intended effect.
HeartWare has also been asked to address issues related to its production and quality procedures and fix problems cited in FDA's inspection.
HeartWare said in May it had observed an increase in complaints about the battery performance of its flagship HeartWare Ventricular Assist System.
The Framingham, Massachusetts-based company's shares were untraded before the bell. They closed at $89.91 on the Nasdaq on Tuesday.
(Reporting by Natalie Grover in Bangalore; Editing by Saumyadeb Chakrabarty)