NEW DELHI – Ranbaxy Laboratories Ltd., India's largest pharmaceutical company, said Friday that the World Health Organization had included another of its HIV-fighting drugs on its prequalification list.

That brought to 18 the number of Ranbaxy antiretrovirals the WHO has approved as safe, effective and high quality.

The drug, Abacavir, will be manufactured at the company's WHO-approved factory in Paonta Sahib, India, the company said in a statement.

The company says its antiretrovirals, or ARVs, have been used by over 500,000 patients in more than 60 countries.

“We are pleased to have one more product on the WHO pre-qualification list,” Ranbaxy CEO Malvinder Mohan Singh said in the statement. “This is yet another significant step in our effort to offer high quality, affordable ARV medicines, for the benefit of the needy HIV patients in the developing and developed parts of the world. We remain committed to supporting the global fight against HIV/AIDS.”

The WHO list of prequalified drugs for HIV/AIDS, malaria, tuberculosis and reproductive health guides procurement decisions by agencies like UNAIDS and UNICEF.

The U.S government has been investigating Ranbaxy since 2006, when the Food and Drug Administration issued a warning letter over manufacturing violations found at a company plant in India.

Ranbaxy has promised to cooperate fully with the investigation.