The state-run Defense Research and Development Organization said the missile, the next in the Agni series, will have a third-stage booster to give it extended range. It said the missile was in the final stage of development and the first test could take place as early as the beginning of next year.

"The system could be made ready for induction within the next two years," Avinash Chander, project director of the Agni program, said in New Delhi.

The DRDO confirmed its secretive K-15 submarine-launched ballistic missile project by giving a technology leadership award to top scientist A.K. Chakrabarty for developing a subsurface missile system for the navy.

Chander said the system had undergone a successful trial and was undergoing mass production.

The 435-mile K-15 SLBM was test-fired earlier this year from a fixed undersea platform off the Visakhapatnam coast in southern Andhra Pradesh state. The K-15 is designed to fit on a domestically produced nuclear submarine that will be launched for sea trials next year.