One of the world's biggest shipping firms, A.P. Moller-Maersk, is rerouting
some of its 50 oil tankers around the Cape of Good Hope.
Norway's Frontline, which ferries much of the Middle East's oil to world markets, may do the same.
The decision comes after the capture by Somali pirates of a huge Saudi Arabian supertanker loaded with $100 million worth of oil, the biggest ship hijacking in history.
The pirate attacks in Somali waters this year have driven up insurance costs for shipping firms and the decision to divert cargo around South Africa risks pushing up prices for manufactured goods and commodities.
Attempts are being made to protect vessels on one of the world's busiest shipping routes, linking Europe to Asia: many analysts say there can be no lasting end to the piracy without peace on land.
“It must be addressed by relevant authorities and the international community,” said Soren Skou, Maersk partner and board member.
“It is not a problem that A.P. Moller-Maersk or the shipping industry can solve alone.”
The African Union's top diplomat, Jean Ping, wants the United Nations should send peacekeepers to Somalia urgently to stop the strife that is fuelling piracy and is aggravated by feuding politicians in the Horn of Africa nation.
There is little hope of any speedy UN intervention in Somalia and NATOe will continue to patrol the seas but not get involved on land.
“Piracy is a very serious challenge and we have to fight it, but I think if you come to the part of these operations, for instance on land, then it is first and foremost up to the United Nations and not organizations like NATO to get deeply involved,” said NATO Secretary-General Jaap de Hoop Scheffe.
African nations were unable to deal with the attacks and called for intervention by Europe, the United States and big Asian nations.
Since the pirates captured the Sirius Star, they have hijacked at least three other ships, maritime officials say. Ransom talks are taking place but Britain said on Thursday that rewarding the gunmen could create more problems.
“Part of the answer to the problem of piracy is going to be to try to engineer some progress inside of Somalia towards some more effective means of governance,” Ambassador William Bellamy, director of the U.S. Defense Department's Africa Center for Strategic Studies, said.
“This is not an area where the United States is unilaterally going to seek to come up with solutions to a problem, regardless of how urgent that problem might be,” he said.