If concluded, the contract would provide for the Russian Federation to supply 48 Sukhoi Su-35 Flanker-E fighter jets for the Chinese air force.
"The sides have practically agreed on the delivery of 48 Su-35 multi-role fighters, worth $4 billion, to China," a Russian Federation Ministry of Defense source told Kommersant business newspaper.
It is not a done deal however, as the Russian Federation is demanding that China guarantee the protection of copyrights on the production of Su-35s without proper licensing.
"Moscow is not only aiming to ensure its presence on the Chinese (fighter) market but also attempting to prevent the potential copycat production of Russian aircraft for subsequent sales to third parties with predatory pricing," a Russian official said.
Russian concerns aren't unfounded, as China has long been suspected of building advanced combat aircraft based on Soviet, Russian and other foreign designs after reworking design fundamentals.