SYDNEY (Reuters) - Major nations failed to reach agreement on Thursday to set up huge marine protected areas off Antarctica under a plan to step up conservation of creatures such as whales and penguins around the frozen continent.

The 25-member Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) agreed, however, to hold a special session in Germany in July 2013 to try to break the deadlock after the October 8-November 1 meeting in Hobart, Australia.

Environmentalists criticized the failure to agree new marine protected areas in the Ross Sea and off East Antarctica, home to penguins, seals, whales and seabirds as well as valuable stocks of shrimp-like krill.

"We're deeply disappointed," Steve Campbell of the Antarctic Ocean Alliance, grouping conservation organizations, told Reuters at the end of the CCAMLR annual meeting. He said that most resistance had come from Ukraine, Russia and China.

Environmentalists said that the United States, the European Union, Australia and New Zealand were among countries pushing for agreement on new protected zones.

Some fishing fleets are looking south because stocks nearer home are depleted and some nations worry about shutting off large areas of the oceans. CCMALR comprises 24 member states and the European Union.

"This year, CCAMLR has behaved like a fisheries organization instead of an organization dedicated to conservation of Antarctic waters," said Farah Obaidullah of Greenpeace.

Among proposals, a U.S.-New Zealand plan would have created a 1.6 million sq km (0.6 million sq miles) protected area in the Ross Sea - about the size of Iran.

And the EU, Australia and France proposed a series of reserves of 1.9 million sq km (0.7 million sq miles) off East Antarctica - bigger than Alaska.

Last week, Hollywood actor Leonardo di Caprio launched a petition to protect the seas around Antarctica with campaigning group Avaaz, saying "the whales and penguins can't speak for themselves, so it's up to us to defend them."

Governments in 2010 set a goal of extending protected areas to 10 percent of the world's oceans to safeguard marine life from over-fishing and other threats such as pollution and climate change. By 2010, the total was 4 percent.

CCAMLR said in a statement that members had identified several regions of the Southern Ocean that warrant high levels of protection.

"These important areas can provide a reference for scientific research on the impacts of activities such as fishing, as well as significant opportunities for monitoring the impacts of climate change in the Southern Ocean," it said.

(Writing by Alister Doyle, Environment Correspondent in Oslo; editing by Mark Heinrich)