GENEVA (AP) -- Rising sturgeon stocks in the Caspian Sea mean caviar-producing countries can export more of the gourmet fish eggs under new quotas, a key UN conservation body said Friday.

The United Nations' Convention on International Trade in Endangered Species, or CITES, praised efforts by Caspian governments since it lifted a yearlong ban on the multimillion-dollar caviar harvest, imposed in an effort to save the endangered fish.

The ban, which ended in March 2002, had halted exports by Russia, Azerbaijan, Kazakhstan and Turkmenistan, but not by Iran.

Caviar has been harvested in the Caspian for thousands of years, but pollution, loss of spawning habitats and over fishing have taken a heavy toll. "After a decade that saw the collapse of sturgeon stocks due to over fishing, the governments in the Caspian Sea region are now fully committed to enforcing CITES regulations," said Jim Armstrong, the organization's deputy head. "As a result of their joint efforts to monitor and manage fish stocks and combat poaching, they are truly starting to turn the situation around."

Recent studies show there are around 11.6 million sturgeons in the Caspian, up from 5 million in 2000, Armstrong said. Around 40 percent of them are adult fish, including caviar-spawning females, up from just 5 percent three years ago.

"These figures are considered conservative," Armstrong said. He praised governments for sacrificing immediate income from caviar sales to protect the fish and build up stocks.

CITES said it had decided in response to raise 2003 export quotas to almost 148 tons, up from the 142 tons allowed last year. The quotas were proposed by the Caspian governments.

The initial 2001 quota, before the ban imposed in June of that year, was around 154 tons.

CITES lifted the ban after deciding the four countries had made good progress in a survey of stocks and in plans for a quota across the region. Iran, the fifth nation on the Caspian, took part in the program to give a coordinated response, even though its management system was already judged adequate. Iranian exports were unaffected by the CITES ban.

Last year's lifting of the ban angered environmental groups, which said the fish was still threatened. Campaigners also said they were unhappy with the latest CITES move. "I think it's extremely unwise to be raising the quota," said Ellen Pikitch, a marine biologist with the U.S.-based coalition Caviar Emptor. "If anything, they should be reduced. It's perplexing to me why CITES has done this." Pikitch told The Associated Press that her own studies in the region suggest the Caspian's sturgeon population has fallen by 39 percent. "We think there aren't enough adult fish in the population to support commercial fishery."

Pikitch noted that the U.S. Fish and Wildlife Service is considering declaring the beluga sturgeon -- which produces the most valuable caviar -- an endangered species under U.S. law. Such a decision would effectively kill sales of beluga caviar in America, which took 80 percent of Caspian exports in 2000.

On the world's legal wholesale market, 2.2 pounds of caviar costs an average of $500, while premium beluga caviar can sell for $4,000.

Until 1991, the Soviet Union and Iran controlled virtually all the world's caviar market, investing heavily in maintaining fish stocks. Following the demise of the Soviet Union, the system collapsed and many entrepreneurs sprang up to replace the state-owned companies.

Official catch levels fell from a peak of about 30,000 tons in the late 1970s to less than one-tenth of that figure in the late 1990s. At the time of the ban, the legal trade was estimated to be worth $100 million a year, but the illegal catch in the four former Soviet republics was believed to be 10-12 times greater than that.

"We don't believe it's at that level now," although CITES does not have solid figures, Armstrong said.

Scientists are able to guess the size of the illegal catch by estimating the number of spawning fish entering the Caspian and comparing it to estimates of the number of fish in the sea. "This gives an indication of how much illegal offtake there must have been," Armstrong said.

Armstrong also welcomed moves in Caspian nations to regulate domestic caviar sales. Most caviar is consumed at home and thus falls outside the quotas.