Under the terms of the RUB30bn (($630m) contract, the state-owned aircraft manufacturer will upgrade more than 50 of the Russian Air Force's MiG-31 aircraft, as reported by RIA Novosti.
Russian Deputy Defence Minister Yury Borisov said: "The armed forces will receive over 50 modernised MiG-31s by the end of 2018."
In 2011, UAC also received a separate contract to modernise 60 of the aircraft by 2020.
Russia currently has around 120 fighters remaining in service, and has already modernised 20 MiG-31 aircraft, according to the news agency.
The MiG-31 Foxhound is manufactured by the Mikoyan design bureau. It is a supersonic interceptor aircraft designed to provide protection against potential airborne threats, including ballistic and cruise missiles.
Powered by two D-30F6 turbofan two-shaft engines, the interceptor is also capable of destroying high and low-altitude targets during day and night, as well as detecting airborne targets at a range of 200m.
The aircraft is designed as a follow-up to the MiG-25 supersonic interceptor jet. It can fly to altitudes of 20,000m and reach a maximum speed of Mach 2.83.
"The armed forces will receive more than 50 modernised MiG-31s by the end of 2018."
The upgraded MiG-31s are equipped with new avionics and fire control systems, and can simultaneously attack six targets within a 280km radius.
In a separate development, the MoD announced plans to hand over more than 150 aircraft and helicopters to the Russian Air Force in 2015, in accordance with the state defence order.
MoD spokesman Russian Air Force colonel Igor Klimov told the news agency that the delivery will include Sukhoi Su-34 bombers, Su-30SM and Su-35S fighters, Yak-130 advanced trainers and Ilyushin Il-76MD-90 transport planes.
The helicopters that will be supplied include Kamov Ka-52 and Mil Mi-28N attack helicopters, Mi-8AMTSh assault-transport helicopters, Mi-35 combat helicopters, and Ka-226 utility choppers.
Russian Air Force Mikoyan MiG-31 'Foxhound' supersonic interceptor aircraft.