Mississippi businesses can learn a lesson from Gulfport-based Trinity Marine Group's playbook for coping with the post-Cold War economy.

The group of 11 medium-sized shipyards has diversified its primary business of new ship construction so that only 35 percent of sales are government contracts, compared with 75 percent in the mid-1980s.Trinity never started out as a wholly defense-based shipbuilder.

"We were in commercial all along," said Harvey Walpert, senior vice president of administration.

Trinity began taking on defense contracts in the early 1980s to alleviate the loss of business offshore.

"At that point, commercial operation was ongoing all the time," Mr. Walpert said. "But it was never 100 percent defense. We'd like to keep it that way."

Mr. Walpert called Trinity an anomaly in the shipbuilding industry.

During the 1980s, several U.S. shipyards went under, and 60,000 jobs were lost in 10 years, but Trinity's size grew sevenfold, from 500 employees to 3,500.

The company posted its largest profit, nearly $31 million on sales exceeding $400 million, in the 1992 fiscal year.

Mr. Walpert attributed Trinity's diversification into commercial markets, such as barge ships and speedboats, to the aggressiveness of John Dane, Trinity's president.

Mr. Dane seized upon business opportunities after the Oil Pollution Act of 1990 mandated that double-hull tankers be used to protect the environment.

Congress passed the Oil Pollution Act in response to the Exxon Valdez oil spill near Alaska. Trinity built ships for oil spill cleanup as a direct result of the accident.

Trinity entered non-defense but government-related arenas by building oceanographic research vessels, landing craft, towboats, pontoon bridges and dredges. Trinity does business with other governments, too. It sells supply ships to the Philippines and patrol boats to Saudi Arabia and Mexico.

The company began building offshore oil supply boats, tractor tugs for tanker escort, dinner cruise ships, ferries and fishing boats.

"We're a much different company," Mr. Walpert said.

Because Trinity has several medium-sized shipyards, it has more flexibility, Mr. Walpert said, and less bureaucracy, unlike large shipyards devoted completely to military work.

"Government yards require a sizable amount of paperwork, administration, overhead costs," he said.