About 100 South Korean drug companies will begin producing generic versions of Tamiflu in August to ease the shortage in supply of the world's only anti-viral drug as its 20-year patient protection has expired, industry sources said Wednesday.

Among the companies are Yuhan Corp., Daewoong Pharmaceutical Co. and Green Cross Corp., an official of the Korea Food and Drug Administration said.

Tamiflu dominates South Korea's market for the anti-viral medication against flu, with sales hitting 59 billion won ($51.7 million) last year compared with 14.8 billion won for Hanmiflu made by Hanmi Pharmaceutical Co., a major South Korean drug manufacturer.

Tamiflu has been in short supply on a chronic basis as Roche Inc., the Swiss manufacturer of the drug, does not have enough production capacity to meet worldwide demand.

Prices of the generic drugs will likely be set at 59.5 percent of the original versions, an industry source said, adding the production of the generic versions will also lower the original drug prices by about 30 percent.

"The production of the generic drugs will not only address the supply shortage but allow patients to get drugs at lower prices," the source said. (Yonhap)