Antarctic treaty nations warned yesterday that if a legal and political system to regulate oil drilling is not developed soon, the ecology of the earth's last unspoiled continent could be seriously damaged.

However, in opening statements at a conference here yesterday, the nations showed no signs of compromising on the issue which divides them: who owns the potentially rich oil reserves off the Antarctic coast.

Seven countries -- Argentina, Australia, Chile, France, New Zealand, Norway and Britain -- have partly overlapping claims to pie-shaped wedges of the icy wilderness around the South Pole. The other six treaty parties -- the United States, the Soviet Union, Japan, South Africa, Belgium and Poland -- do not recognize these claims.

Major oil companies are pressuring the 13 nations to open Antarctica to offshore exploration. But environmentalists are lobbying for a "world preserve" for scientific research and wildlife protection.

No support was evident among treaty delegates for such an approach. All seemed anxious to press ahead with a new treaty to regulate mineral development.

Unless an agreement is negotiated soon, "unilateral commercial exploration will almost certainly take place," said Merwyn Norrish, New Zealand's ambassador to Washington. "Uncontrolled exploration could create a very serious situation from the environmental point of view." their territorial claims. "Argentina's activity in the Antarctic goes

Scientists are concerned that oil spills in the stormy Antarctic seas, which are linked to the rest of the earth through deep ocean currents, could harm fisheries and even affect the world's climate.

"We can no longer ignore (mineral) issues," said P. D. Oelofsen, head of South Africa's delegation. "Unless nations reach agreement in the foreseable future, the likelihood of uncontrolled mineral activity will increase dramatically. The disastrous effects not only for the treaty but for the environment do not need to be spelled out."

All parties spoke enthusiastically of the past 20 years or international cooperation for preserving the continent as a haven for scientific research, free of weapons. They were optimistic that the difficult issues of sovereignty could be worked out.

However, countries such as Argentina, Chile and New Zealand stressed their territorial claims. "Argentin'a activity in the Antarctic goes back 75 years," said Angel Maria Oliveri Lopez, head of his delegation."We could not support any agreement which would ignore this political reality."

Ambassador Keith Brennan, Australia's delegation chief, said in an interview that the countries involved have "diametrically opposed opinions on the rights to the oil. States that exercise sovereignty feel they have complete control. States which don't say, 'Nothing of the kind. We have as much right as you have.'"

The parties are hopeful that an agreement on fisheries conservation, pending for the last two years, can be worked out in the next three weeks of the conference. The agreement would seek to control the rapidly expanding harvesting of krill, a protein-rich shrimp, in Antarctic waters.

The three weeks of negotiations, which are behind closed doors as is traditional in the "Antarctic club," will also include discussions of telecommunications policy, the collection of meteorological data, tourism and oil contamination of the environment.