Andrew M. Ockershausen, who joined WMAL in 1950 as a page and whose guidance made it one of the country's most successful AM outlets, announced yesterday that he had resigned to pursue "some entrepreneurial" plans.

A successor is expected to be named Monday.

Ockershausen, 57, is a third-generation Washingtonian who has participated in many civic and business endeavors. Most recently he has been at the forefront of the effort to acquire a major league baseball team for Washington.

A member of the D.C. Baseball Commission, Ockershausen said yesterday, "I want to do everything I can do to get a baseball team for this city." He emphasized he would not be taking a full-time job with the commission and is "not part of an ownership group and I don't want to be part of a management team."

His plans, he said, are "working for Andy Ockershausen for the first time in my whole life," and will include several interests. "I've got a lot of investments in the city," he said.

When Ockershausen joined WMAL, he worked for $21 a week and streetcar passes. He became station manager 10 years later. For a while he was general manager of both WMAL radio and television. He is currently the highest ranking manager at the station, serving as executive vice president and general manager.

"This is the only place I have ever worked and I am scared. WMAL will always be in my heart," he said. The highlights of his career at WMAL have been "working with Harden and Weaver, being involved with the Redskins, the people who work here and the listeners."

The decision to leave, said Ockershausen, was "agonizing. Opportunity doesn't knock but once. We have been through all the travails of the merger and the station had its best year ever last year." WMAL became part of Capital Cities/ABC Inc. in January when ABC was bought by Cap Cities.

Under Ockershausen, the station became the home for some of Washington's most popular personalities, including the top morning team of t Frank Harden and Jackson Weaver, has raised millions of dollars annually for charity and is a comforting escape for listeners who don't want fast-talking deejays or hard-driving music.

The news department of the station has won numerous awards, including at least five Peabody Awards and several other citations for documentaries and spot news coverage.

In addition, Ockershausen's own editorials, notably a series on the need for legislation and programs to control driving under the influence of alcohol and drugs, have garnered several awards. He said yesterday he would not be helping the reelection campaign of Mayor Marion Barry or participating in any organized politics. "But I will still help the city," said Ockershausen.