In another twist to the ongoing saga to replace the Air Force's aging fleet of aerial refueling tankers, United Aircraft Corp. of Russia is planning to bid on the $40 billion contract, according to a person familiar with its plans.

United Aircraft, an aerospace consortium owned by the Russian government, will seek to offer a tanker version of its Ilyushin Il-96 wide-body jetliner, dubbed the Il-98, this person said. The planes would be largely built in Russia, and assembled in the U.S., this person says. United Aircraft will...