Surging U.S. oil supplies are increasing the nation’s influence in global crude markets while diminishing the power of the Organization of Petroleum Exporting Countries, according to Russia’s biggest oil producer, Bloomberg said June 17.

“OPEC has reduced its influence,” Igor Sechin, Chief Executive Officer of OAO Rosneft, said Wednesday in St. Petersburg. “The only market that has a full set of financial, technical and resource instruments is the U.S.”

U.S. output has surged to the highest level in more than four decades as a combination of horizontal drilling and hydraulic fracturing, or fracking, unlocks supplies from shale formations. OPEC is responding to the expansion by increasing its own supplies in a strategy to defend market share, breaking with a previous approach of curbing output to boost prices.

Operating costs are now the most important thing in determining oil prices, which will recover in two to three years, Sechin said.

While crude oil has rebounded from a six-year low in January, it remains 44 percent down from a year ago. Brent crude, the global benchmark, fell 56 cents to $63.13 at 5:01 p.m. local time on the London-based ICE Futures Europe exchange.

OPEC’s 12 members maintained their joint output target of 30 million barrels a day at a June 5 meeting. They’ve exceeded that level for the past 12 months.