Both sides set a target of doubling bilateral trade to 20 billion dollars by 2015.
Medvedev arrived in India on Tuesday, seeking to fend off growing international competition for lucrative Indian defence contracts that were once monopolised by Moscow.
His trip capped a flurry of top-level diplomatic activity that has seen the leaders of all five permanent members of the UN Security Council beat a trade-focused path to India’s door over the past six months.
British Prime Minister David Cameron visited India in July, US President Barack Obama, French President Nicolas Sarkozy and Chinese Premier Wen Jiabao have passed through over the last six weeks.
The two sides agreed to pursue plans for Russia to build two additional generating units at Koodamkulam nuclear power plant in the southern Indian state of Tamil Nadu, where it is already setting up two reactors.
Energy-hungry India is one of the world’s biggest markets for nuclear technology with plans to reach a nuclear power capacity of 63,000 megawatts by 2032, from the current level of 4,560 megawatts.