Russia is planning to sign in December an agreement with India on the preliminary design of a joint fifth-generation fighter aircraft, a senior Russian aircraft industry official said on Wednesday.

Russian Sukhoi holding and Indian Hindustan Aeronautics Limited (HAL) agreed in early 2010 to jointly develop a fifth-generation fighter jet, tentatively dubbed PAK FA.

"An agreement with India on the pre-design of the PAK FA will be signed in December," said Alexei Fyodorov, head of Russia's United Aircraft Corporation.

The sides agreed to develop both a single-seat and a two-seat version of the aircraft by 2016, focusing on the single-seat version in the initial stages of development.

The new aircraft will most likely be based on Russia's T-50 prototype fifth-generation fighter, which has already made several test flights and is expected to join the Russian Air Force in 2015.

Russia has been developing its fifth-generation fighter since the 1990s. The current prototype, known as the T-50, was designed by the Sukhoi design bureau and built at a plant in Komsomolsk-on-Amur in Russia's Far East.

Russian officials have already hailed the fighter as "a unique warplane" that combines the capabilities of an air superiority fighter and attack aircraft.