Cathay Pacific, responding to pressure from an array of environmental groups in Asia, has announced that it will no longer carry shark fin on its cargo flights.

The Hong Kong-based carrier, one of the world’s largest cargo airlines, said in a statement that it would “stop shipping unsustainably sourced sharks and shark-related products.”

Dozens of marine-protection campaign organizations had sent a joint petition to Cathay Pacific seeking the cargo ban. They cited Hong Kong government figures that showed 10,500 tons of shark fin were imported into the territory last year, with Cathay alone handling as much as 650 tons. The airline has said that the real figure was much lower.

A Cathay spokeswoman, Elin Wong, said that the cargo ban “will not have a material impact on our business.”

“We did this,” she commented, “because we now have compelling evidence that the majority of shark fishing is incompatible with our position on sustainable development.”

A statement from the airline cited “the vulnerable nature of sharks, their rapidly declining population, and the impacts of overfishing for their parts and products.”

“This is a milestone in our efforts to end the trade of products like shark fin in Hong Kong,” said Ran Elfassy, director of Shark Rescue, a marine conservation campaign in Hong Kong. “The city is the leading trade hub for these endangered animal products, and airlines are significant players in the supply chain.”

Another environmental campaigner in Hong Kong, Alex Hofford, said Wednesday that Cathay’s decision was “very heartening for everyone in the conservation community — and the greater population at large.”

Hong Kong is the Asian hub for the trade in shark fins, serving as the principal transit point for fish and seafood products headed to markets in mainland China. Shark fin soup, which is essentially tasteless, is still seen as a status symbol in China, Hong Kong and ethnic Chinese communities. It remains a staple at corporate events and wedding banquets, even for those of modest means.

“Rapid economic growth across Asia in recent years has catapulted millions into the ranks of those who can now afford the dish,” my colleague Bettina Wassener reported in July.

Six weeks ago, China said it would ban shark fin soup at official banquets, although it could take up to three years for the ban to be fully implemented. The ban was reported by Xinhua, the state-run news agency.

A handful of luxury hotels and hotel chains have taken shark fin soup off their menus, including the Shangri-La and Peninsula hotels here in Hong Kong. The Berjaya chain of luxury hotels and resorts also no longer serves the soup at its 18 hotels worldwide, including six properties in Malaysia and hotels in London, Manila and Singapore.

Several American states have criminalized the sale, use or possession of shark fin, but those bans remain scattered. As Rendezvous reported this summer, DNA samples from soup served in restaurants in 14 American cities showed that some were even using fins from scalloped hammerhead sharks, an endangered species on the Red List of the International Union for the Conservation of Nature.

Some ethnic Chinese residents in Calgary, Alberta, have objected to their city’s recent ban on shark fin soup. The Calgary Herald, in a story on Tuesday about the issue, said the soup was still available at some restaurants in the city, “though often as an off-the-menu item for $50 to $200 a bowl.”

“Shark finning — the practice of catching a shark, slicing off its fins and then discarding the body at sea — takes a tremendous toll on shark populations,” said the Pew Charitable Trusts. “Up to 73 million sharks are killed every year to primarily support the global shark fin industry, valued for the Asian delicacy shark fin soup.”

Others put the death toll higher: “We’re killing 100 million sharks a year for shark-fin soup,” said the marine conservationist and shark expert Richard Ellis. “It’s insane.”

A third of open-ocean sharks and rays are now threatened with extinction, primarily due to overfishing, according to the Shark Specialist Group at the I.U.C.N.

“Due to the vulnerable nature of sharks, their rapidly declining population, and the impact of overfishing for their parts and products, our carriage of these is inconsistent with our commitment to sustainable development,” Cathay Pacific said in a statement.

The company’s Web site says, “Cathay Pacific and Dragonair do not serve shark’s fin soup either inflight, at Cathay Pacific City, Dragonair House or at any corporate events or meals which are organised or subsidised by the company.” (The new cargo ban also extends to flights on Dragonair, a Cathay subsidiary.)