The nation's two longshore unions will negotiate new contracts with shipping lines and stevedores in 1996 at a time of unprecedented economic change in the maritime industry.

On the West Coast, negotiations for the master contract between the Pacific Maritime Association and the International Longshoremen's and Warehousemen's Union begin in the spring.The East and Gulf Coast divisions of the International Longshoremen's Association, meanwhile, are preparing for negotiations for a new master contract with the Carriers Container Council to cover longshore workers from Maine to Texas. The current contract expires in October 1996.

Both sets of negotiations will begin after Congress considers legislation that would deregulate the maritime industry by phasing out the Federal Maritime Commission. Many port and maritime-industry officials believe the legislation will mean further consolidation of the port industry and lead shipping lines to limit their port calls.

Benny Holland, an ILA vice president with responsibility for Southern ports, compared the situation to that faced by the airline industry when it was deregulated in the 1970s. Since then, he said, many airlines have gone out of business or curtailed services. When maritime is deregulated, he added, "I see the big boys calling the shots and making the deals."

As more cargo flows on truck and rail, Mr. Holland said, fewer ships will use U.S. ports, cutting the number of jobs for longshore workers.

For the ILA, however, the biggest threat in recent years has been nonunion companies that pay workers much less than the $21 an hour earned by ILA members.

In the South, where right-to-work laws make union organizing difficult, the ILA is facing severe competition from nonunion operators, particularly in the breakbulk industry. In the Gulf, for example, some nonunion longshore workers receive as little as $6 an hour.

The ILA "can no longer sit idly by and let the nonunion (companies) get bigger and bigger," ILA President John Bowers told the ILA convention in Orlando, Fla., last summer.

However, the steady expansion of nonunion operators may force the ILA to make some wage concessions. Managers at some ports have already asked for the union's cooperation.

In a speech to the ILA convention last summer, David Tolan, chairman of the Carriers Container Council, said many executives at container-shipping companies wonder why they pay $21 an hour for longshore wages, and most benefit costs, when breakbulk vessel operators pay as little as $10 an hour and much less in benefit costs.

"I'm going to ask for your support in saving" the council, Mr. Tolan told the ILA.

He said more than 80 percent of the cost of longshore benefits are paid by the container carriers. That is out of proportion to the actual number of longshore workers they use, he said.

"Our members are also checking their costs and asking why they should remain members of the CCC," Mr. Tolan said.

Mr. Bowers replied that employers get a lot from their relationship with the ILA because they have not experienced waterfront strikes. "You've been fair," he told Mr. Tolan, who is vice president of labor relations for Sea- Land Service Inc.

Judging from recent events, contract talks could be more difficult on the West Coast.

In mid-August, the ILWU launched a one-day strike that shut down the entire West Coast waterfront. The job action was called to protest what the union called "long-simmering" disputes, including an alleged desire by some employers to close small breakbulk ports and a move toward privatization that could lead to nonunion operations.

At the time, some industry executives viewed the strike as a display of force to show employers that labor has the ability to cripple West Coast ports.

In another action in September, the ILWU struck terminals owned by the Japanese carrier Nippon Yushen Kaisha when talks broke down over a contract for office workers who voted to join the ILWU.

The weeklong strike was part of an effort by the ILWU to expand its jurisdiction to nontraditional jobs.