For the first time in a decade, oil producers are facing a real test of their unity.

As the OPEC cartel meets in Cairo on Saturday, exporters are being pummeled by a triple whammy of lower prices, falling demand and declining revenue. The group, whose members account for more than 40 percent of global oil exports, is desperately seeking ways to stop the drop in prices, which have fallen from their summer peaks at a record pace.

But the Organization of Petroleum Exporting Countries is increasingly torn between its moderate members, led by Saudi Arabia, which can afford a period of lower oil prices, and countries with high government spending, like Iran and Venezuela, which have become much more dependent on high prices.

These two groups have often clashed in the past, and as prices plummet the tensions are once again bubbling to the surface.

When oil prices collapsed to $10 a barrel in 1998, OPEC producers managed to set aside their squabbles to push prices back up. Thanks mostly to a growing global economy and tightening supplies, producers saw a sharp rally in oil prices over the last 10 years.

But as the global economy sputters, the recent decline in oil prices has been staggering, and producers have been incapable of slowing the slide.

After rising above $145 a barrel this summer, oil prices have fallen below $55 a barrel, their lowest level in more than three years. Instead of coasting on growing demand, producers are confronted with a significantly different environment, and must adapt to a world of slowing consumption and overflowing oil supplies. They must also contend with hundreds of billions of dollars in lost revenue.

In the last two months, OPEC agreed to cut its output by 2 million barrels a day. While analysts say members of the cartel are generally abiding by their pledge, the effect on the market has failed to materialize so far.

Since the group’s last meeting a month ago, OPEC’s reference basket price — an average of oil grades sold by producers of the cartel, including Saudi Arab Light and Sahara Blend from Algeria — has fallen by more than half, reaching a low of $42 a barrel last week.

The cartel’s traditional hawks have been pushing for a more aggressive cut in production this week, and there is talk of trying to rally non-OPEC producers to help stabilize the market. The oil minister of Venezuela, Rafael Ramirez, suggested the cartel should reduce its production by an additional 1 million barrels a day, a position that was endorsed by Iran.

But a decision is far from certain and some producers are dragging their feet. OPEC’s president, Chakib Khelil, said the group needed to see how well producers were complying with their prior commitments to pare supplies before agreeing to a new cut. The group is scheduled to meet again in Algeria next month.

Sharing the burden

“There are disagreements between producers,” said Greg Priddy, an oil analyst at Eurasia, a political consulting group in Washington. “Some members are below their pain threshold, especially Iran. But the Saudis will not allow themselves to be strong-armed. They want to see how everyone is complying before agreeing to another round of cuts.”

Guy Caruso, the former administrator of the Energy Information Administration, said the Saudis have been cautious so far, trying to balance their budget requirements with concerns about the global economy. Even if OPEC agreed to a new cut in production, analysts doubt that all the countries would abide by their quotas, and it would fall to Saudi Arabia to shoulder the brunt of the cutbacks.

“The Saudis have the longer-term view,” Caruso said. “They don’t want to be in the situation they were in the 1980s when almost all the burden fell on them to defend the price.”

The drop in prices is threatening the economic and political foundations of many oil producers. Iran’s populist president, Mahmoud Ahmadinejad, is expected to run for re-election next year while Hugo Chavez of Venezuela is being contested in local elections at home. Both countries need oil above $90 a barrel to balance their budgets, according to various estimates.

“The Iranians, the Russians and the Venezuelans, who had benefited the most from the rise in price, are the ones paying dearly now with the collapse,” said Lawrence Goldstein, a veteran energy analyst.

But while different producers have competing agendas, the drop in prices has been so rapid that even moderates are feeling the sting.

“Prices have gotten to a point that they are hurting everybody now,” Goldstein said. “A world of $50 oil or less is in no one’s interest within the organization.”

Coordinated efforts

This weekend’s meeting may include proposals to open consultations with producers outside of the cartel, the Iranian envoy has indicated, and could set the contours for a coordinated response between OPEC and non-OPEC producers like Mexico and Russia. In the late 1990s, Norway and Mexico trimmed their production to bolster oil prices after the Asian economic crisis.

The Russian energy minister, Sergei Shmatko, suggested Tuesday that his country might reduce its output in tandem with OPEC. He said that Russia required $95 a barrel next year, otherwise its budget would be strained and its currency would suffer.

But with its production already declining this year because of a lack of investments, it is unlikely that Russia will follow through, analysts said.

Downward pressure

Over the last decade, OPEC has stepped in three times with large production cuts to stop prices from falling — in 2001, 2003 and 2006. Only once, however, did producers fully comply with their pledges to trim their output, according to analysts at Barclays Capital.

When prices last fell toward $50 a barrel, at the end of 2006, members of the cartel agreed to cuts totaling 1.7 million barrels a day but they cut only 900,000 barrels a day, according to Barclays.

Yet prices rebounded because oil production from non-OPEC producers, like Mexico and Norway, was disappointing and consumption kept rising.

Now, even if OPEC agrees to reduce its output further, it is doubtful that oil will rebound soon. In the past, it has typically taken three to six months for oil prices to rise after OPEC trims supplies, according to Deutsche Bank.

“In terms of crude oil, we believe downward pressure on prices is likely to persist throughout next year,” according to a report by Deutsche Bank. “OPEC will struggle to cut production as fast as world growth is slowing over the next 12 months.”