NEWPORT BEACH — Vuong H. Tran says that every piece of information he can collect about Vietnam may one day help to build a bridge between the United States and the country he fled in 1975.

As relations between Washington and Hanoi begin to thaw, Tran has joined two other Southland businessmen to form a trade consulting firm in Newport Beach that specializes in business prospects with Vietnam.

"American companies that plan to trade with Vietnam must think in the long term," said H. Frank Chew, a co-owner of the business--Vietnam 2000--and a former program director at USC's Graduate School of Business Administration.

Trade between the United States and Vietnam has been prohibited since 1975, the year the Americans withdrew from South Vietnam.

But there have been increasing signs that the Bush Administration is preparing to restore trade relations with Vietnam. Last month, the two nations said they would set up an office in Hanoi to resolve cases of U.S. soldiers missing in action, and Washington announced that it will send the first U.S. economic aid to Vietnam since the war's end--$1 million for artificial limbs for those wounded in the war.

In the near term, business opportunities in Vietnam will probably include food processing equipment, telephones, satellites and medical technology, Vietnam 2000 executives said.

"Vietnam will need machines to repair its infrastructure--like airports and ports--to conduct its trade," Chew said. "I believe that repairing the infrastructure will take some time, and the real impact of establishing a new business there will not be effective until the year 2000."

The Vietnamese government will also need sophisticated drilling equipment to extract offshore oil and minerals, he said.

Vietnam 2000 was founded in January by Chew and two Vietnam natives, who believe that there will be normal Washington-Hanoi relations by early 1992. The company provides consulting services and market studies on Vietnam.

Vietnam 2000 is already advising several Southern California companies, including hotel and high-tech companies, said Buu Q. Do, a tall, energetic former high-ranking military officer in South Vietnam. Do, a co-founder, declined to name which Southland companies.

International investors have begun to consider Vietnam one of Asia's most promising trade areas. Vietnam's oil, mineral and marine life are largely untapped. The country's approximately 66 million people are highly literate--and are paid even less than China's workers.