Angel Jones, city manager for Gaithersburg since 2008, has resigned, city officials said Thursday.

Jones, whose last day is Friday, ran government affairs as the Montgomery County city faced tough economic times. During her tenure, city officials approved the first property tax rate increase in 45 years, a measure taken to maintain Gaithersburg’s enviable status as a debt-free municipality.

In a statement, Gaithersburg Mayor Sidney A. Katz said Jones resigned to "pursue other career opportunities,” but did not provide specifics. Jones, who did not respond to a phone request for comment Thursday, said in a statement that she left the city in a “strong financial position."

Deputy City Manager Tony Tomasello will serve as acting city manager as a search for a permanent replacement begins, city officials said.