The giant supertankers that dominated the world's oil-shipping lanes for a decade are now a fast-vanishing species, the dinosaurs of their trade.

In shipyards in Taiwan, South Korea and other Asian ports, some of the greatest of the oil-bearing tankers are being cut into pieces of scrap to be fed into steel furnaces, returning to the red-hot kettles from which they came. That is the fate of the French supertankers Batillus and Bellamya, owned by Shell France.

Others roll listlessly an anchor off oil ports around the world, relegated to storage vessels. Such is the lot of the Seawise Giant, the largest of the supertankers.

And there is no interest in building more of the largest of the giant tankers. According to the American Petroleum Institute, 126 VLCCs (Very Large Crude Carriers) with capacity of 240,000 tons, and up were built between 1976 and 1980. Between 1981 and 1983, only 6 were built. "To our knowledge, there are no [construction] contracts for VLCCs now," said Richard J. Queegan, general manager of Texaco Inc.'s marine department.

The rapid eclipse in the value of these ships has added another strain to the international banking system, which may have as much as $10 billion in loans outstanding on oil tankers, according to U.S. banking executives. As much as 40 percent of that figure may have to be written off, some bank executives estimate.

"An awful lot of shipowners are very, very stretched," John Scully, senior vice president at Morgan Guaranty, said last month. so many of the biggest ships are idle or being scrapped that they are having harder time repaying the loans.

The supertankers are casualties of the same forces that have caused gasoline price wars, closed down filling stations on street corners all over the United States, triggered billion -- dollar takeovers in the oil industry and brought the once-powerful Organization of Petroleum Exporting Countries to the verge of collapse.

Those forces are the worldwide glut of oil, the resulting drop in oil product prices and the opening of new oil fields that have fundamentally changed the geography of petroleum transportation.

To defend against the punishing escalation of oil prices in the 1970s, the world's consumers and businesses learned to make do with less oil and fewer petroleum produces. A lot less.

While energy conservation was expanding in the 1970s, new sources of oil in Alaska, Mexico and the North Sea were coming on stream. These new oil fields not only added to a growing worldwide glut of oil, they also shortened the petroleum supply lines because of their closeness of major oil-consuming Markets in America and Europe. And that was a heavy blow to the economics of the supertankers, which had been designed for the long voyages between Persian gulf oil fields and refineries in Europe and Japan.

"Instead of originating in the Middle East, the oil began coming out of the North Sea and Mexico, which is short haul. For VLCCs, that was disastrous" said Philip J. Loree, chairman of the Federation of American Controlled Shipping, a lobbying organization for the U.S. ocean shipping industry.

Improvements in the Suez Canal made it more profitable to ship crude oil on smaller tankers from the Persian Gulf to Europe by that route, rather than on a giant tankers via the longer route around the Cape of good Hope.

And, in recent years, there has been a marked increased in imports of petroleum products -- gasoline and fuel oil -- rather than unrefined crude oil, particularly into the eastern United States. This created a demand for smaller faster vessels more suited to a rapidly shifting market for petroleum products.

Loree offered a vivid measure of the shrinkage in seaborne oil traffic over the past decade -- the total number of ocean miles traveled in a year by oil tankers multiplied by the total weight of their cargos. In 1973, before the first of the OPEC price escalations, the world's oil tankers rolled up 10.2 billion ton-miles. Last year, that total was cut almost in half.

It is a fate few would have predicted in 1973, when shipyards were awash in construction orders for new tankers. The next year, when Noel Mostert published his best-selling book "Supership," the age of the behemoths seemed just to be drawing. The book is Mostert's account of a passage aboard the British supertanker S.S. Ardshiel, from Bordeaux around the Cape of Good Hope to the Persian Gulf and back with more than 200,000 tons of crude oil -- enough, his book notes, to serve the entire energy needs of a city of 40,000 for a full year.

Until the advent of the supertankers, the standard for measuring size in ships was the old Cunard Line passenger ships, the Queen Elizabeth and Queen Mary, he said in the book. The banker Ardshiel, at a length of 1,063 feet, was 32 feet longer than the old Queen Elizabeth (which was destroyed by fire in Hong Kong harbor in 1972). Filled with oil, the Ardshiel carried more than 214,000 deadweight tons, or the actual weight of cargo.

And as big as the tanker was, with a deck almost a quarter-mile long, the Ardshiel was far from the biggest. It was less than half the size of the Globtik Tokyo, with a deadweight of 476,292 tons, for example. The French supertankers Batillus and Bellamya weighed in at 553,000 deadweight tons each in 1976.

The largest of them all was the 564,739-ton Seawise Giant, built for the C. Y. Tung Group in 1981.

In the mid-1970s, when he wrote his book, Mostert speculated that even these monster were soon to be overshadowed. "Nobody doubts that tankers will continue to advance beyond this. Japanese and British shipbuilders have been busy for some time with design and dockyard preparations for what must surely be the penultimate [sic] in vessels, a million tonner, and, God knows, the way things have been going, there is bound to be somebody already thinking beyond that!"

To Mostert, who lived above the Straits of Gibralter, with a clear view of its parade of oceangoing vessels, the supertankers were not ships at all, as lovers of ships define the term, but hulking oversized barges fitted with engines and berths for crew. The growing size of the supertankers oil cargoes also represented to him a growing environmental hazard, magnified by the difficulty of controlling tankers of that immense size.

According to Texaco's Queegan, the VLCCs and Ultra Large Crude Carriers (ULCCs, with capacities over 40,000 deadweight tons) were obsolete almost at birth. "By the time they were built, the business was already changing. the Seawise Giant made one or two voyages over the past several years and has been in storage for the past two. the 400,000-ton-plus ships never really met their design goals. They are the classic white elephants," Queegan said.

"We don't see the supply-and-demand balance of VLCCs coming into equilibrium until the early 1990s, at the earliest," he said. It appears unlikely now that anything larger than 250,000 deadweight tons will be built.

The ULCCs aren't likely to be seen ever again, he said. "It's a very limited future, if there is any future at all."

Drewry Shipping Co., quoted by the Reuter news agency last month, estimated that, while only 11 per cent of the tankers smaller than 225,000 deadweight tons are not in use, more than 60 percent of tankers larger than 300,000 tons are out of action.

True to the gambling nature of the shipping business, however, while many of the multinational oil companies and other owners are selling and scrapping superships, a few investors are buying in hopes of a turnaround in the tanker trade.

The odds are enticing. Construction of a new VLCC could cost more than $50 million, one marine banker said. Existing ships of that size are available on the scrap market now for $4 million to $6 million apiece. For example. Lowes Corp. recently purchased several 300,000 dead-weight-ton tankers and is storing them in Norweigian waters, apparently betting that a turnaround in demand for tankerr tankers will come sooner rather than later.

But it will take a steep, lasting slide in oil prices and a continued shrinkage in the tanker fleet to create a turnaround, Loree aid.

Meanwhile, the international lenders who support shipbuilding are in no mood to risk more capital off supertankers. The shipping industry has been jolted by the financial emergency facing the C. Y. Tung Group of Hong Kong, owners of the Seawise Giant, which disclosed debts of $22.4 billion in November. In August, the world's largest tanker company, Sanko Steamship, filed for protection under Japan's bankruptcy laws.

"The Tung situation makes everyone nervous," Michael Revell, head of Marine Midland Bank's shipping group, told the Financial Times. His bank, a leader in international ship lending, is pulling out of that field. "It's all very sad."