Frits van Riet, Nedlloyd Lines' top man in the United States, will be returning to the Netherlands at the end of this month to direct all shoreside activities for the carrier outside of Europe.

The move is in line with the Rotterdam-based shipping and transport conglomerate's new approach to the business."We're decoupling land from sea," Mr. van Riet said in Atlanta Wednesday.

His successor will be J. T. Teeuw, who currently directs Ned- lloyd's participation in consortia with other carriers to the Far East, Australia, New Zealand and South Africa.

Nedlloyd Lines BV is a subsidiary of Royal Nedlloyd Group NV, one of the world's largest ocean and intermodal carriers. Over the past two and a half years, Mr. van Riet has been trade director for the North Atlantic, responsible for its three trans-Atlantic liner services to the United States and its service to the west coast of South America. He also has been president of Nedlloyd Lines U.S.A. Corp., which oversees all of the company's operations in the United States.

Mr. van Riet's arrival in the United States in November 1987 coincided with Nedlloyd's transfer of its U.S. headquarters to Atlanta from New York and the shifting of responsibility for its trans-Atlantic shipping services to the United States from Rotterdam.

Mr. Teeuw assisted him in making the arrangements for Nedlloyd's move to Atlanta, but has not previously worked in the United States, according to a Nedlloyd spokesman.

Mr. van Riet, who announced his new position at a dinner here Tuesday evening, said his new title will be director, container flow management, regions. He will be in charge of Nedlloyd Lines marketing and sales as well as inland transportation services in all parts of the world except Europe. The director of container flow management for Europe is H.J.M. van der Wyck.

Under the restructuring program, to announced officially next week, A. van Langeveld, one of Nedlloyd Lines' two top executives, will direct the carrier's ocean transportation activities. His title will be interim director of container slope management.

The restructuring is in line with a strategy Nedlloyd announced early last year, of putting greater emphasis on inland transportation services, including warehousing and trucking.

The focus thus far has been in Europe, where Nedlloyd has made major acquisitions in Germany, Italy, Spain and Switzerland to complement its existing operations.

Mr. van Riet said an important part of his new job will be to capitalize on those improved European transportation operations in marketing the ocean carrier's worldwide liner services.

"Our new strategy is to create more value" for international shipments, he said.

The company has no immediate plans for a similar expansion of its inland transportation services in the United States, but Mr. van Riet said he would not rule out the possibility of doing so in the future.

Mr. van Riet said he believes Nedlloyd ranks as the world's fourth largest transportation conglomerate.

The parent Royal Nedlloyd Group, consisting of some 32 companies, last year earned 252.3 million guilders ($135.6 million) on revenue of 6 billion guilders. Although the company reported an operating profit from ocean shipping of 111.3 million guilders, its services between Europe and North America have been plagued by losses since starting up in 1986.

Mr. van Riet said he has been pleased by the line's cargo volumes in its U.S.-European services. "But the results could be better. I don't think there is anybody making money on the North Atlantic," he said.