Leaders in Chester are looking for a chief executive to run the city’s daily operations after city administrator Sandi Worthy resigned Monday night.

Worthy submitted a letter of resignation to Chester City Council at its regular meeting, said Council Member Annie Reid. The council accepted the resignation, which was effective April 21, Reid said.

The resignation gave no reason for Worthy leaving the job, Reid said.

The city will begin advertising immediately for a chief executive, Reid said.

Worthy had been on leave for about a month before her resignation, Reid said.

Worthy had been the city administrator in Chester since August 2013, said Carla Roof, Chester human resources director.

Roof is handling top executive duties for the city until a replacement is hired, said Reid.

The city administrator in Chester, the Chester County seat with a population of about 5,500, is the chief executive of all city departments and employees. The town council hires the administrator.