The complex, which produces polyethylene, is operated by Uzbekistan's state oil and gas company Uzbekneftegaz, a strategic partner of Russian state gas company Gazprom which is a major shareholder in Gazprombank.
Uzbekistan's President Shavkat Mirziyoyev sent a request to officials at the energy and finance ministries to seek a $300 million loan from the Russian bank, according to a statement on Mirziyoyev's website.
Gazprom has been operating energy projects in Uzbekistan since 2002.
Gazprombank, Russia's third biggest lender by assets, said in a statement that it aimed for further development of mutually beneficial relations with Uzbekistan in various areas including energy and was considering the $300 million loan as part of cooperation with Uzbekneftegaz.