Alicia Mundy, a reporter for the weekly Alexandria Port Packet newspaper whom some city officials blamed for sparking the controversy that led to two grand jury investigations of Police Chief Charles T. Strobel, has resigned.

Strobel was cleared of wrongdoing by a state grand jury in early 1985, and two weeks ago was acquitted by a federal jury of charges of perjury and obstructing justice.

Known for her witty, sometimes vitriolic column about city affairs, Mundy, 32, said she had planned to resign since October. She denied reports that her departure was prompted by a dispute with editor Patricia Durkin, who disagreed with her handling of the Strobel stories.

Mundy said she soon will be working for another Virginia news organization, but she declined to identify it.

John W. Hanes Jr., the Packet's publisher, supported Mundy's coverage through months of controversy over Strobel's management techniques and the issue of whether the chief improperly ended a drug investigation. Commenting on Mundy last week, Hanes said, "The constructive part is that the police department will never be run as it was in the past."

A different view came from Mayor James P. Moran Jr., who said of Mundy's resignation: "It couldn't be soon enough. There's never been, and I suppose will never be, a more irresponsible member of the media than Malicious Mundy."

Strobel filed a libel suit against the Packet and Mundy, but he dropped it before it could go trial.

Mundy's opinion column, Mundy's Mutterings, in which she frequently aimed barbs at city officials or policies, won her a 1985 Virginia Press Association award.