More than 100 energy companies have had their credit ratings put on review for possible downgrade by Moody’s Investor Service.
Shell, Total and Statoil are included in the move as oil prices are expected to recover more slowly than companies expect.
A spokesman for Moody’s said: “Even under a scenario with a modest recovery from current prices, producing companies will experience much lower cash flows.
“Today’s review for downgrade considers that much weaker industry fundamentals have potential to warrant rating changes.”
The past year has seen Shell, Total and other oil companies hit by the collapse in crude prices.
Earlier this week Shell said it expected its fourth quarter results to drop at least 42%.
A total of 69 exploration and production service companies in the US were put under review, as well as 11 mining companies.
Moody’s has also reduced its estimated for both West Texas Intermediate and Brent to $33 for the year.