Russian oil producers that have refining assets are likely to cut their planned investments if the price for Brent oil falls to below $47 per barrel, VTB said Tuesday.

Such integrated oil companies will break even at $28 per barrel of Brent oil, unless they take cost-cutting measures, the bank found in a research.

The findings came as oil prices have more than halved from their peak in July. A barrel of Brent traded below $70 on Tuesday.

Oil refining units are the most vulnerable to the price decrease, as they are profitable only at $60 per barrel or higher, the research said. Production units, however, would generate profit even at $15 per barrel, it said.

In terms of net income, Gazprom Neft and TNK-BP are the most sensitive to the price decline, the research said. They lose 24 percent and 20 percent in profits, respectively, for each cut of $10 per barrel in Brent price assumptions.

At the "current level of market pessimism," $50 per barrel is the most bearish scenario for oil stock valuations, VTB said. Even so, the costs of crude production globally would not allow prices to stay that low for long, it said.

At peak oil prices, the long-term consensus for Brent hovered around $100 per barrel, VTB said.

Gas exports would become unprofitable according to earnings before interest, taxes, depreciation and amortization if the Brent price went below $30 per barrel, VTB said.

Gas export prices are based on those of oil, with a lag in pricing of at least six months, so Gazprom earnings for next year do not yet appear to reflect the price decreases, VTB said.

"However, 2010 earnings could be fully exposed should the oil weakness continue," analysts Lev Snykov and Svetlana Grizan wrote in the research.