By Selina Williams and Daniel Gilbert 

France's Total S.A. said it was seeking alternative nondollar financing for a major gas project in Russia days after Exxon Mobil confirmed it would stop drilling in the Russian Arctic, as major oil companies start to feel the bite of western sanctions on their expansion plans there.

While oil majors have played down the impact of western sanctions on assets already producing oil and gas in Russia, the comments from Total and Exxon Mobil show how projects key to their future growth are now being directly affected.

Exxon Mobil, based in Irving, Texas, said it had obtained a license from the U.S. government to wind down drilling of its first well in the Kara Sea, where it has an exploration joint venture with state-owned OAO Rosneft, struck in 2011, that the companies estimate will cost at least $3.2 billion.

Exxon didn't make clear whether it would take longer than the Sept. 26 deadline to halt operations mandated by the latest round of sanctions, which bar U.S. companies from collaborating with Russian partners to drill for oil in the Arctic or in shale-rock formations.

An Exxon spokesman didn't immediately say whether the license would give the company additional time. A spokesperson for the U.S. Treasury Dept., which administers sanctions, said it doesn't comment on license applications.

Meanwhile Total's Chief Financial Officer Patrick de la Chevardière said on Monday the company was looking at financing its share in the $27 billion Yamal liquefied natural-gas project in Chinese yuan, Russian rubles and euros.

"The effect of U.S. sanctions was that Yamal LNG will be prevented from raising any dollar financing," Mr. de la Chevardière told a news briefing in London. Total is developing the onshore Yamal project in Russia's Arctic north with independent Russian gas producer OAO Novatek and China's CNPC.

Sanctions on Russia's resource sector were designed to punish Russia for its aggression in Ukraine. U.S. officials have said they could be lifted if they see evidence that the Kremlin is complying with the terms of a cease-fire signed earlier this month.

But if the measures persist, they could imperil Exxon's joint venture with OAO Rosneft and one of its biggest opportunities to find new supplies of oil and gas.

Total is in turn relying on Yamal, which is expected to start up in 2017, to provide a big chunk of the French's company's future production growth. Yamal is estimated to hold proven reserves of 800 million barrels of oil equivalent.

U.S. and EU sanctions imposed so far include financing limits on some banks and energy companies and restrictions on technology transfers and equipment to develop deep-water and offshore Arctic oil and onshore shale oil. They come on top of asset freezes and travel bans on dozens of officials and tycoons, including one of Novatek's biggest shareholders-- Gennady Timchenko.

Yamal is a complex project requiring western technology that Russia lacks, such as the liquefaction plant that will supercool the gas into liquid form so it can be transported around the world in giant tankers.

The project has so far managed to proceed despite the sanctions because the companies involved have been able to pursue other avenues for finance.

Russia relies on oil and gas to provide the bulk of its revenues and Yamal is vital to Kremlin plans to increase the country's share in the fast-growing global LNG market.

Write to Selina Williams at selina.williams@wsj.com and Daniel Gilbert at daniel.gilbert@wsj.com