With the price of the global benchmark, Brent crude oil, falling 1.5 percent on Monday to $88.89 a barrel, many analysts said Saudi Arabia, OPEC’s dominant member, might be rethinking its strategy.

“Saudi comments indicate that it may have shifted from a strategy of holding prices at around $100 a barrel to a focus on market share,” said Jeff A. Dietert, head of research at Simmons & Company, an independent investment bank. “That means there is not an immediate floor on oil prices.” He said he thought that Saudi Arabia was trying to slow production growth in the United States.

Oil prices have reached levels not seen since the Middle East and North Africa turmoil began in 2011 because of an unusual combination of factors: Demand for petroleum products is declining worldwide, particularly in Europe, just as the global market is flooded with oil.

Many energy experts say the world market, which consumes about 90 million barrels a day, has one million barrels more than it needs, although that could easily change if the Islamic State, also known as ISIS, attacked Baghdad and threatened the southern Iraqi oil fields, or if militias suddenly renewed their blockades of oil ports in Libya.

Prices of Brent and the American benchmark, West Texas intermediate crude, have slid by 20 percent or more since early summer, when prices briefly spiked because of the Islamic State offensive in Iraq. The American benchmark dropped particularly hard over several days last week, suggesting a glut in several parts of the country, particularly West Texas, where production has been ramping up in recent years.

On the supply side, the United States shale drilling boom has been a critical factor. Domestic production has reached 8.7 million barrels a day, about a million barrels a day more than just a year ago and the highest level in nearly a quarter century. Imports from OPEC countries have been cut in half since 2008, forcing countries like Saudi Arabia and Nigeria to compete with one another in Asia, cutting their prices starting last week.