India and Russia are in advanced stage of negotiations in a USD 10 billion-defense deal to modernize outdated Soviet Union and Russian equipment. The deal will include an S-300 missile defense system, license to produce 1000 tanks, development and production of medium transport aircraft, submarines, and conceptual work on a fifth generation fighter aircraft and an aero-engine. Russia is backing a proposal from Sukhoi to sell the same aircraft being inducted into Russian Air Force. The timely supply of spares is a major issue with Russian equipment.