Three-way trade talks are planned by the United States, the European Economic Community and Japan, an administration spokesman confirmed yesterday. The talks would be aimed at avoiding potential disputes on trade issues such as imports of Japanese cars.

Such meetings would be a "logical follow-up" to the discussions held by seven major nations and EEC representatives at the Ottawa economic summit last month, the spokesman said. The "conceptual agreement" to hold such talks was not included in the communique after the summit, possibly because the other nations at the summit were not directly involved in the three-way arrangement and would not have wanted it in the communique.

Previous trade talks have involved only two of the three parties at a time, and a spokesman said they hope that a more coherent and reliable policy can be worked out if representatives of all three sit down together at regular but informal meetings. In the past, both Europeans and Americans have feared that if the Japanese agree to limit exports to one party, they will compensate by stepping up their sales to the other.

The details of the new meetings, including when and where they will be held, have not yet been completed, a spokesman said. American representation at the meeting will probably be headed by Special Trade Respresentative William Brock, although a final decision has not been made, the spokesman said.

Areas of potential trouble for the United States, Japan and the EEC include trade in autos, steel, data-processing equipment, insurance services and synthetic fibers. Temporary accords now exist for autos and steel, but officials do not rule out future disagreements.

The slow growth in the world economy has made all trade issues potentially more inflammatory. Participants at the Ottawa summit agreed that liberal trading arrangements are crucial for the health of the world economy.