The United Nations has lifted a ban on beluga caviar exports after Caspian Sea states agreed to limit catches of the fish from which it is taken.
The Beluga sturgeon can take up to 20 years to reach maturity.
Beluga caviar is the most expensive variety of the delicacy and can cost thousands of dollars a kilo.
Almost all trade in caviar was banned last year because the sturgeon is fast disappearing from the Caspian, the source of about 90% of world caviar.
Environmentalists have attacked the UN decision, calling it irresponsible.
Experts estimate the Caspian's caviar stocks have fallen by more than 90% since the late 1970s because of overfishing - both legal and illegal.
'Brink of extinction'
UN-sponsored conservation body Cites has granted Azerbaijan, Kazakhstan, Iran, Russia and Turkmenistan permission to export 3.761 tonnes of beluga caviar in 2007.
Ellen Pikitch, co-founder of Caviar Emptor, a group campaigning to protect Caspian Sea sturgeon, criticised the decision, saying the beluga sturgeon was on the brink of extinction.
"This is irresponsible behaviour by international trade officials," she said.
Last month, Cites gave the same five countries the go-ahead to sell 96 tonnes of other varieties of caviar - 15% below the level set in 2005.
Monday's announcement also allows China and Russia to export about 3.2 tonnes of Amur sturgeon roe and 4.2 tonnes of Kaluga sturgeon roe.