Japan's No.3 drugmaker said in a statement the venture, to be called Japan Vaccine Co, would sell vaccines marketed by Glaxo and Daiichi Sankyo, and the firms plan to expand the business as new vaccines in the development pipeline are approved.

Japan has been slow to approve vaccines such as the combinations used abroad to cover diphtheria, pertussis, tetanus, polio and haemophilus influenzae type B in a single injection, and this under-developed market presents a commercial opportunity for drugmakers.

Daiichi said the venture will aim to improve access to vaccines in Japan and create more combination vaccines by bringing together the two companies' products and technologies.

The joint venture will launch in July, and will market products including Glaxo's cervical cancer vaccine Cervarix and rotavirus vaccine Rotarix?and Daiichi's seasonal flu vaccine.

Shares of Daiichi Sankyo were up 1.2 percent at 1,518 yen after the announcement, which was flagged in a Nikkei business report the previous day, outperforming a 0.8 percent rise in the benchmark Nikkei average.

(Reporting by Nobuhiro Kubo and Chris Gallagher; Editing by Michael Watson and John Mair)

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