Russia hopes to sell up to 100 passenger jets to Iran in what would be the largest such deal ever for Russia's aviation industry, officials said Tuesday. Russian and Iranian officials have agreed to start negotiations on a contract for the delivery of 100 Tupolev Tu-204 and Tu-214 airliners to Iran, said Maxim Sysoyev, a spokesman for Russia's state-controlled United Aircraft Corporation. He said that the contract was expected to be signed later this year and the deliveries could start next year. The planes would be delivered over 10 years, he said. Russian news reports said the deal could be worth up to $2.5 billion. Iran has about a dozen Soviet-built Tu-154 airliners. In 2006, Russia negotiated the sale of five Tu-204s to Iran. Russia has maintained close ties with Iran and is building its first nuclear power plant in the southern port of Bushehr, which is expected to be launched later this year. If the deal with Iran goes through, it would probably mark the single largest order for Russian commercial planes in history, including during Soviet times. It also raises doubts about the ability of the nation's beleaguered aviation industries to fulfill the contract. The twin-engine Tu-204 and its Tu-214 version were designed in the late 1980s to compete with Boeing's 757, but just a few dozen of the planes have been built. The nation's aviation industries melted down after the 1991 collapse. Amid Russia's oil-driven economic boom of recent years, the Kremlin has put forward ambitious plans for the revival of the aircraft industry and aggressively courted foreign customers.