The chief spokesman for the domestic steel industry warned yesterday that unless the Tresuary Department can find a way to slow the surge of steel imports from Europe, the industry is apt to begin filing anti-dumping charges with the federal government.

When the Carter administration fashioned a special set of minimum prices for steel imports that took effect in May, domestic steel companies withdrew most of the unfair trade suits they had filed against their foreign competitors.

But Lewis W. Foy, chairman of the industry trade group and Bethlehem Steel Corp., told reporters yesterday that a jump in steel imports in July - following two months of decline - calls into question the effectiveness of the administration's special program.

He said if the August import figures continue high and Treasury is unable or unwilling to revise the so-called trigger price program, "You'll find dumping actions filed by everybody who has a dumping action to file."

But the chairman of the American Iron and Steel Institute left plenty of room to back off from filing new or previously withdrawn dumping suits, which are both expensive to file and laborious to process.

Foy said he would meet with administration officials next week to discuss the problem and said he was optimistic that some solution acceptable to both the government and the industry could be devised.

Foy said the government might consider a two-tier trigger price program, one based on Japanese costs of production and the other based on the higher-cost Europeans.

The trigger pricing program was devised to prevent foreign steelmakers from selling their products in the U.S. market below the price of the lowest-cost producer in the world, Japan. The U.S. industry has long claimed that if foreigners sold steel at full cost of production and shipping, American steel makers would be able to compete successfully with foreign-made steel.

U.S. steel companies claim, however, that the trigger prices have been set too low and still permit foreign steelmakers to unfairly undercut the prices of domestic producers.

Foy said that Japan has behaved well under the trigger price program and has contained its steel shipments to the United States.

But European producers have continued to dump steel here at an accelerating rate, Foy said.

European producers shipped 58 percent more steel to the United States during the first seven months of this year than it did during the first seven months of 1977.

Foy admitted privately that while the trigger price program is grounded in the economics of producing steel, its actual effect is an much political as it is economic. The mechanism is designed to transmit pressure to world steel producing countries to dissuade them from selling large quantities of below-cost steel here so they do not have to lay off workers back home.

The steel trade group called yesterday's press conference to release a report that argues both Japan and Europe historically have sold steel in the United States at prices well below those-charged in their homes markets - the classic case of dumping.

The report, prepared by the Newton, Mass. consulting firm of Putnam, Hayes & Barlett, Inc. - said that in 1976 and 1977 foreign dumping of steel in the United States cost steel makers (in lost earnings) and steel workers (in lost wages) a total of $4 billion. That comes about both because domestic makers sold less steel than they would have if foreigners did not dump and because domestic steel makers could have sold their product at higher prices.

After the briefing, Foy said privately that prospects of the steel industry for the rest of the year seem fairly strong. But he said he is worried about an economic slowdown that would reduce demands for steel products.

Furthermore, Foy said, some of the steel that has been imported this year may be in warehouses and might be sold during the last four months of 1978. That would cut into steel orders at domestic mills.

Foy said Bethlehem is studying its forecast that domestic mills would ship 97 million tons of steel this year to see if it should be revised downward.