Capital Cities/ABC Inc., the owner of radio station WMAL-AM, announced yesterday that it had appointed Fred Weinhaus, a veteran employe of the company's radio division, to succeed Andrew M. Ockershausen as head of WMAL.

Weinhaus, 49, has been president and general manager at WPAT-FM in New York. He began work yesterday with the same title at WMAL, two days after Ockershausen suddenly resigned as executive vice president and general manager, previously the top post at the station where he had worked for 36 years.

Weinhaus said he did not plan any immediate changes at one of Washington's most popular stations. "Certainly from what I am told it is a great radio station, and I am not going to do anything to make it less than that. What modifications might take place would take place over a period of time," he said.

Like WMAL, WPAT has enjoyed a long period of profitability, repeatedly ranking as the most-listened-to station in the country with a "beautiful music" format and usually placing among the top five rated stations in the competitive New York market. "WMAL just seemed to offer a new challenge . . . the programming was so different. It provided the opportunity to get involved in personality radio and heavy sports and to stay in a market in the Northeast relatively close to New York." Weinhaus said he would continue the station's commitment to Washington area civic projects.

A native of New York City, Weinhaus attended the University of Miami and is married with three children.

At a press briefing yesterday Ockershausen said he had not been forced out because his management style conflicted with Capital Cities' reputation as a conservative, low-key company. "I was forced out by myself," said Ockershausen. "I don't know if anything bothered them . . . You can have any style you want as long as you are successful."

Though his specific business interests are still evolving, Ockershausen, a member of the D.C. Baseball Commission, said he plans to spend considerable time as an "active lobbyist for baseball.