D.C. Mayor Anthony A. Williams, vowing to improve the condition of the city's recreation centers, ballfields and senior centers, yesterday asked for and received the resignation of the director of the Department of Recreation and Parks.

Betty Jo Gaines, 56, who has worked for the agency for 34 years, including the past five as director, will be replaced within a month by an administrator who likely will come from outside D.C. government, said Williams's chief of staff, Abdusalam Omer.

Meanwhile, Omer announced yesterday that the mayor has selected Andrew Altman, former planning director in Oakland, Calif., to take over the District's planning office, which is central to efforts to redevelop neighborhoods east of the Anacostia River, along Georgia Avenue and downtown.

The two moves come as Williams continues to remove administrators he is not satisfied with and fill vacancies he inherited or is creating. Among the posts needing permanent replacements are the corporation counsel, the city administrator, chief of procurement, Health Department director and now parks director.

Gaines offered her resignation in a letter to Williams yesterday after a morning conversation with Omer. She declined a request for an interview, but told Williams in her letter that she "leaves with a sense of pride."

Gaines oversaw a 480-employee agency with a $36 million operating and capital budget. It operates 17 recreation centers and playgrounds, 15 senior centers, 21 day-care facilities, 42 pools, 381 parks and several youth programs.

Until her replacement is named, the agency's chief of policy and planning, Diane Quinn, will be acting parks director.

Omer would not comment on why Gaines was asked to leave. But he said the mayor wants to see major improvements in the city's park and recreation programs, including better maintenance of ballfields, faster action on construction projects and enhancements in recreation centers and offerings for seniors.

Williams also has said that some of the city's playground equipment does not meet national safety standards.

In her letter, Gaines said she is proud of her record of making do with limited budgets.

"In spite of shrinking resources, we were able to maintain a high standard of service delivery and to launch numerous innovative programs," she said.

Altman, who will take over the 18-person Office of Planning, was selected because of his experience in Oakland and other cities in managing neighborhood revitalization projects similar to what the District needs, Omer said.

In Oakland, Altman oversaw a city effort to fix up run-down, inner-city commercial districts, and he pushed for approval of a waterfront redevelopment plan. He previously worked in Los Angeles as a special assistant to the head of the city's redevelopment agency and to then-Mayor Tom Bradley. He spent the past year at Harvard University on a fellowship studying urban planning.

Tersh Boasberg, chairman of the Committee of 100 on the Federal City civic group and a member of the panel that interviewed four finalists for the planning job, said Williams made an excellent choice in Altman.

"He is absolutely terrific," Boasberg said. "There are so many things in the city that have been stalled until adequate comprehensive planning can be done, from our neighborhoods to the waterfront, the Navy Yard, St. Elizabeths, a possible baseball stadium and the commercial development near New York and Florida avenues."

CAPTION: Mayor Anthony A. Williams wants improvements in the District's Recreation and Parks Department.