Russian lawmakers have proposed a set of measures that, if adopted by the Kremlin, could see the country halt crucial supplies of titanium to U.S. aircraft manufacturer Boeing.
Russia's lower house of parliament, the State Duma, is to consider legislation banning a list of U.S. imports in response to sanctions recently imposed by Washington on Russian officials and businessmen.
Lawmakers in Moscow said Friday they had prepared a list that has suggested a possible ban on titanium sales to Boeing. The list also slaps limits on cooperation in nuclear and space technology.
Further restrictions on the imports of American farm products and curbs on food and drink imports were also suggested.
The aircraft industry is increasingly reliant on titanium as a strong but lightweight material for use in wing assemblies, steering wheels, hydraulic systems and a number of other parts. A Boeing 777 has a reported 8.5 to 12 percent of titanium in its airframe.
Russia's VSMPO-AVISMA is the world's largest titanium producer and the main supplier to Boeing. The Russian firm told Reuters on Friday that stopping that trade could push the company out of emerging markets.
Boeing also has a joint venture with VSMPO-AVISMA's parent company Rostec Corporation. The two firms run a plant in western Russia devoted to manufacturing finished parts for airplanes.
The trade-restrictive proposals from the Russian politicians are at an advisory stage and it remains to be seen if the Kremlin will adopt them into law.
In an email Friday, Timothy Ash of BlueBay Asset Management said the Russians were issuing Washington with a clear warning.
"I assume the reason they are not going straight to an imposition of sanctions is that they want to let the U.S. administration and its allies mull over the implications of further sanctions actions against Russia," he told CNBC.
Boeing shares fell around 1.2 percent shortly after the open of trade. Boeing told CNBC they are "aware and monitoring closely".