Reflecting the growing competitiveness of its product, Bethlehem Steel Corp. finished loading yesterday 5,500 tons of steel coils on a ship headed for its traditional antagonist -- Japan.

The shipment is the first steel sold to a Japanese company from Sparrows Point's hot strip mill, which recently underwent a $200 million modernization. The changes have improved the quality of the steel and made its price more competitive, Bethlehem spokesman G. Ted Baldwin said.

The shipment comes shortly after the expiration of quotas on foreign steel imports, a move many U.S. steel companies fear will hurt their business.

Those companies, including Bethlehem, had lobbied for extending the quotas, which were in effect for eight years.

Now that the quotas are gone, some U.S. steel companies are considering filing suit against foreign steel producers charging them with dumping and selling subsidizing steel.

Meanwhile, U.S. steel producers are looking to boost their exports.

"We are competitively located [near the coast] and we have the ability with the hot strip modernization to compete on quality and price," Mr. Baldwin said.

The Sparrows Point plant has shipped steel to Japan in the past, primarily low-cost, semi-finished slabs. The plant exported about tons of steel last year, Mr. Baldwin said.

Yesterday's shipment, which was carried on the Norwegian-flag ship Star Leikeanger, was to an unidentified Japanese producer of square tubing, panels and roofing materials.

The steel mill also has a 45,000-ton order for hot rolled coils from Titan Industrial Corp. of New York for a customer in Italy, Mr. Baldwin said. That order will be delivered in three shipments beginning in June.

U.S. steel exports have risen steadily in recent years, from a low of 930,000 tons in 1986 to 6.3 million tons last year.

At the end of March, the voluntary restraint agreements, which had limited foreign steel imports to 20.2 percent of the domestic market since 1984, expired when President Bush pledged that he would not renew them.