Several key software vendors soon will offer U.S. exporters and importers an opportunity to begin using international computer networks to schedule and track the movement of their products.

The different electronic data interchange (EDI) systems, while currently based on specific modes of transportation, are expected to merge over the coming decade, and companies failing to use a system will face much more efficient competitors, industry analysts said. Right now, most of those systems are a conglomeration of mostly proprietary networks that are limited in their range.EDI is a computer-based standard for telecommunication that radically reduces the costs of paper bookkeeping and provides users with a host of instantaneous and highly efficient tools like point-to-point shipment tracking. Its use in international business is inevitable, and global adherence to the still-evolving United Nations-backed standard, Edifact, may be only five to 10 years away.

Major transportation companies and multinational corporations pioneered the use of EDI because it cut overhead and raised efficiency, but start-up costs of development were high.

Smaller, domestic-market-oriented businesses avoided the initial investment in EDI unless they were forced by their large buyers to do so.

But now that all the major modes of the U.S. transportation industry have developed EDI systems and personal computer-based software for their customers, exporters and importers will have to make the investment in EDI or be left behind, analysts said.

Still, analysts contend that the current generation of systems will offer only limited windows into the global spectrum of information needed by traders to make business decisions.

Moreover, they said, the cost effectiveness of the systems - which are organized along separate U.S. transportation modes - is not clear.

"Since all EDI systems are imperfect, there is a real trade-off between starting anew, or making do with old EDI systems. But it is time to make the leap if a company has not yet started," said Eugene Milosh, president of the American Association of Exporters and Importers, the international trade group in New York.

The imperfection in the systems that Mr. Milosh referred to is the lack of interconnectivity between modes of U.S. transportation, and between U.S. and foreign systems.

The U.S. airline industry, for example, uses its own Cargo-Imp system, not based on Edifact, but has developed a program, Cargo-Star, to translate into the Edifact protocol.

Airlines in other nations, meanwhile, have developed Edifact-based systems.

One new PC-based EDI system keyed to the air transportation mode that will be released soon is WNALink, offered by World Net Associates of Dallas. That system is linked through a proprietary telecommunications switch or gateway to the Aviation Exchange system, which itself is a common gateway to several different airline EDI systems.

Aviation Exchange is a product of Teledyne Brown Engineering of Huntsville, Ala.

"We're working as strategic partners with Aviation Exchange," said Marc De Cesare, executive director of World Net, whose product will link exporters and importers to 41 international locations through a network of international customs brokers and freight forwarders.

While the U.S. trucking and rail sectors also have well-developed domestic systems, their reach into foreign systems is very limited.

In the maritime sector, a group of U.S. carriers have banded together to develop an Edifact-based system under their Information Systems Agreement umbrella. However, their soon-to-be released product, Ocean, will not have a

window into the air or land-transportation sectors, at least initially.

Ocean is being designed by TSI International Ltd., of Wilton, Conn., to be the standard EDI system for all maritime companies and their 500,000 customers, said Steve Rosen, the director of marketing for the company.

The systems agreement, which just published an updated maritime EDI guide for the latest version - 3030 - of the U.S. standard X-12, also plans to publish a translation dictionary to convert X-12 systems to Edifact, to help users adapt to the global standard.

Still, an exporter may need several such systems to effectively compare the costs and schedules of transportation modes in order to select the best combination for shipping goods. This would leave an opening for companies that add value to disparate EDI systems for a customer.

"Evolving to Edifact is like having to switch to the metric system. With all the different standards in use, it can get confusing to a user," one system vendor said.