Ann Dandridge, Baltimore County's communications coordinator, resigned yesterday to take the part-time position of executive director of the Baltimore County Citizens Foundation.

Ms. Dandridge also will be a marketing coordinator for the county Department of Economic Development.

As communications coordinator, she was a spokeswoman for County Executive Roger B. Hayden.

Her resignation is effective Monday.

"I enjoyed my work in the Office of Communications, but the change is a good career move for me," she said.

Her background has been mostly with foundations and fund-raising.

Mr. Hayden said that the foundation needs a director and that "Ann's experience makes her the perfect person for both positions."

He announced the formation of the private, nonprofit citizens foundation in December. The purpose of the foundation is to raise money for social programs.

Ms. Dandridge took over the Office of Communications in May, the third person to head the office since Mr. Hayden became executive in December 1990.

No successor has been named.