General Electric: With $146 billion in revenue last year, the sprawling, global industrial and finance conglomerate has one of the biggest American footprints in Russian. But as a share of GE's overall revenue, Russia represents about 1 percent of its business, according to CEO Jeff Immelt.
"It's very small," he told CNBC. "But we'd like Russia to be in better shape. I like Russia in the long term."
Last year, GE's sales rose 23 percent in Russia, where it sells everything from power generating equipment to jet engines, part of its global strategy of expanding its business in developing economies that are building new industrial capacity and other infrastructure.
Demand in the rest of the world will more than offset the impact of the Russian crisis, said Immelt, who forecast 10 percent growth in overall profits next year.
Exxon Mobil: As a major player in Russia, Exxon Mobil already suffered a significant setback in September, when U.S. sanctions forced it to halt drilling a remote Arctic offshore oil well that was part of a long-term joint venture with Rosneft, its state-controlled oil company partner. The sanctions were imposed to punish Russia for escalating tensions in Ukraine.
Exxon Mobil's $3.2 billion joint venture, signed in 2011, was to have developed a series of oil and gas fields in Siberia and several other Arctic Ocean locations.
Russia's untapped Arctic oilfields are believed to contain vast reserves that could be worth hundreds of billions of dollars. But those finds may be worth considerably less if oil prices remain at lower levels.
Citibank: With more than 50 branches in 12 cities across Russia, Citibank has the largest presence of the major U.S. banks.
In 2013, Citi generated profit of $285 million on revenue of $1.1 billion in Russia, up 10 percent from 2012, from its customer base of more than 3,000 institutional clients and over a million retail customers, including 500,000 credit card holders.
The deepening economic slowdown in Russia will likely cut into loan demand, but Citi's exposure in the country could be limited because those loans are almost entirely funded by local deposits, according to Fitch Ratings.
Fitch also noted that retail and corporate banking is about its half business, with investment banking making up the rest.