The Commerce and Industry Ministry said this is being done in view of the long gestation period of defence contracts to mature.
Currently, the initial validity of industrial licence for defence sector is seven years, further extendable up to 10 years.
"...The initial validity of industrial license for defence sector is being revised to 15 years, further extendable up to 18 years for existing as well as future licenses," the Ministry said in a statement.
The government has said it wants to bring India's rank within top 50 in terms of 'ease of doing business', from 142nd currently, according to the last World Bank report.
Last year, the government raised the foreign direct investment policy in the defence sector to 49 per cent, from the earlier 26 per cent.