The United States and three Western European nations have signed an agreement on deep-sea mining claims that removes another potential irritant to the troubled Atlantic alliance and gives new hope to American companies that this country can circumvent the mining provisions of the Law of the Sea Treaty.

France, West Germany, Britain and the United States agreed to resolve through consultations any conflicting claims filed by sea-bed mining consortia under their existing laws and to consult each other before issuing any authorization for sea-bed mining operations.

The agreement does not in any way indicate that any of the three European signatories will join the United States in refusing to sign the Law of the Sea Treaty, but it appears to enhance the prospects that this country can negotiate separate mining agreements outside the treaty with at least some of the industrialized nations.

The U.S. mining industry fears it will not be allowed access to the mineral riches on the ocean floor because the United States -- alone among major industrial nations--has announced its refusal to sign the treaty. Yesterday, it welcomed the agreement with the West European nations as a possible breakthrough toward pacts that would circumvent the treaty.

"I think it's good news," said Charles Cook, vice president of the American Mining Congress. "It's significant that France, Britain and West Germany are in on this. They're the only ones besides us who have the wherewithal to do any actual mining, the ones who have the technology."

"With the treaty, the door was shut on us," said Conrad Welling, executive vice president of Ocean Minerals Co., an ocean-mining consortium consisting of Lockheed Corp., Standard Oil Co. of Indiana, Royal Dutch Shell and Royal Bos Kalis Westminster, a Dutch marine construction company.

"The only other recourse we have is through agreements with individual countries," he said. "This is a step toward that."

But Lee Kimball, director of an independent group, Citizens for Ocean Law, who has closely monitored treaty developments, said, "You'll hear some people claim this is a breakthrough, but in no way does this indicate that Britain, France or Germany is going to back off from the treaty and join our scheme."

The treaty, which was approved overwhelmingly in a U.N. vote, would give exclusive control of the vast deposits of manganese, nickel and cobalt on the ocean floor to an international authority that would approve mining ventures, issue licenses, validate claims, set production limits and distribute profits among signatory nations.

The United States has said it will not sign because the treaty's sea-bed mining provisions are irreconcilable with this country's economic philosophy. If the other industrialized nations accept the international regulatory program, however, the United States faces the possibility of being frozen out of potentially lucrative and strategically vital mining operations.

In the four-nation interim agreement signed Thursday, the European nations reserved the right to ratify the Law of the Sea Treaty. The framework agreed to permits exploratory work in progress to continue until the treaty takes effect and, as a senior administration official put it, allows the Europeans to "keep their options open."

"It is framed so as not to prejudice the position of any of the parties in respect to the Law of the Sea convention," the State Department said.