LONDON, Oct 11 (Reuters) - AstraZeneca has signed a deal to co-promote Johnson & Johnson's novel prostate cancer medicine in Japan, giving the British company a new drug revenue stream and bolstering its Japanese presence.

Financial terms of the agreement, announced by AstraZeneca on Friday, were not disclosed.

The drug, abiraterone, was submitted for regulatory approval in Japan in July 2013. It is already on the market in the United States and Europe, where it is sold under the brand name Zytiga.

"This deal is a strong strategic fit for AstraZeneca, reinforcing both our focus on oncology as a core therapy area and Japan as one of our key growth drivers," said Marc Dunoyer, executive vice president for global products and portfolio strategy at AstraZeneca.