At the same time, some of the geopolitical tensions that surrounded the move of oil prices toward $150 a barrel also showed some signs of easing.

Image The New York Stock Exchange on Wednesday. Credit... Chip East/Reuters

The Bush administration said on Tuesday that it would allow a senior diplomat to attend a meeting of European and Iranian negotiators over Iran’s nuclear program, in what would be the highest-level talks between American and Iranian representatives since 1979. Fears of a military strike by Israel or the United States on Iran’s nuclear operations helped push oil prices to record highs last week.

“Things have been looking rather glum over the past couple of days,” said John Kilduff, an energy analyst at MF Global. He called the news about talks with Iran and the unexpected increase in oil inventories “a one-two punch for bears” that could signal a deeper drop in prices in coming weeks.

Oil prices have risen more than sevenfold since 2002 as fast-growing demand in developing countries has outpaced the growth in new oil supplies. In the past year, they’ve more than doubled, pushing gasoline prices above $4 a gallon in the United States and leading to frenzied efforts in Congress to address runaway energy costs.

But as high energy prices ripple through the economy, there is growing unease at how much they are contributing to higher costs for everything from food to consumer goods. Consumer prices have risen at their fastest pace in 17 years in June, according to a government report released Wednesday.

Businesses are also being hit hard. Automakers and airlines like General Motors and Delta Airlines are losing billions of dollars and laying off thousands of employees.

Consumers have sharply reduced their gasoline consumption in the face of record prices. Gasoline demand in the United States, for example, fell 5.2 percent last week, according to a nationwide survey by MasterCard, its 12th consecutive weekly drop.