A leading analyst predicted here today that steel imports will begin increasing again within two years despite President Reagan's program to limit them.

There may be a "blip" of lower imports over the next year or two because of so-called voluntary restraint agreements negotiated by the Reagan administration, but foreign steel sales will begin to grow over the five-year length of the president's program, Joseph C. Wyman said.

"Trends of more imports will continue," Wyman, a senior vice president for research at Shearson Lehman/American Express, told a meeting of the American Institute for Imported Steel and the Texas Association of Steel Importers.

He said the trend toward greater imports of all kinds of goods is "unmistakable," and not easily derailed by complex government programs.

As if to prove Wyman's point, signs are emerging that new suppliers are beginning to flood the American market with steel products even as the traditional importing nations conclude agreements to curb their sales in the United States.

Turkey, for example, supplied no steel to the United States in 1974 and just 1,000 tons in 1983. Last year, however, its steel shipments increased to 44,000 tons, and sources here said its imports are likely to be three to four times as great in 1985.

There are questions being raised, moreover, as to whether all that steel is being produced in Turkey or whether foreign steel producers are following the lead of textile manufacturers and moving their products from one country to another to get around quota restrictions.

During the 177 days since President Reagan announced in December that steel imports should be limited to 18.5 percent of the American market, eight countries have agreed to quotas, and negotiations are under way with six others, Assistant U.S. Trade Representative Charles Blum told the importers.

Turkey, hardly a major supplier, was not one of them.

In Washington Wednesday, however, Deputy U.S. Trade Representative Robert Lighthizer said federal regulators will have to be alert to the possible problem of new suppliers moving in to fill the gap in imports caused by the quotas.

Wyman painted a gloomy future for the American steel industry, whose management he said displayed a "smugness" that kept them from taking steps a decade ago to stave off imports.

He said it took steel industry executives from 1964 to 1977 to even admit that Japanese steel makers were more efficient than they were.

Steel producers and auto makers in this country "are part of a larger economic happening" -- the trend toward greater imports -- "where the cards are stacked against them," Wyman continued.

"The sooner they understand that, the better off they will be."

Despite the odds against them, he added that steel makers need to become as efficient as they can, but with high wage rates and the strong dollar they must "be aware that even that won't be good enough."

Blum, the assistant U.S. trade representative who played a lead role in negotiating the steel agreements, pointed to trouble spots ahead with Canada and the European Community, both major suppliers.

He said the United States had called for consultations with the Europeans on 17 steel products that were not included in a 1982 agreement, but which have been entering the United States in increasing amounts.

According to steel importers, this issue could mushroom into a major trade conflict between the United States and its European allies, who are likely to resist further restrictions on their steel sales in this country.

Blum said that steel imports from Canada also ballooned beyond their historical norms last year and need to be watched, although January shipments dropped sharply.

He noted that steel prices are continuing to drop instead of increasing as they would be expected to under import restraints, and indicated unfair trade practice is the likely explanation.

But Fred Lamesch, president of the American Institute for Imported Steel and head of TradeARBED Inc., a New York steel importing company, said it is still to early to judge the restriction's impact on prices. He predicted, though, that domestic producers will increase prices because decreased imports "will no longer be a factor in setting prices in the U.S. market."