As the crisis in Russia's economy due to collapsed energy prices and Ukraine fallout shows little sign of abating, Renault is emerging as one of the auto sector's most exposed companies.

The company posts its latests financial results and guidance tomorrow (February 12) and its statements on its Russia operations will be keenly awaited.

A research note from analyst Max Warburton at Bernstein Research suggests that while Russia's problems have been a minor drag on Renault operating profit thus far, Russia will prove a "very major problem" in 2015.

Warburton points out that Russia is Renault's third largest market, with over 200,000 units a year at peak and that no other company is as exposed to Russia (the Renault-Nissan Alliance, including Avtovaz dominates the market, with share of over 30%).

"The collapse in the Russian currency, economy and car market means Renault is set to take some pain," he says. "We believe Russia will prove to have been a relatively minor drag on operating profitability in H2 2014 but will prove a very major problem in 2015. Furthermore, we expect Renault to write down a large part of its significant Russian investments when it reports 2014 numbers later this week."

Warburton also notes that in Renault's financial statements the Avtovaz stake is in the books at EUR508m, versus a current market value of EUR90mn and that the Avtovaz business plan assumes an exchange rate of 40 roubles to the euro - almost twice the current rate.

"We are cutting our numbers again with this report," he says.