Northern Lehigh School District has extended the deadline to fill a vacancy on its board of directors.

Candidates were asked to turn in letters of application to the district by 3 p.m. Thursday afternoon to occupy an empty seat on the board.However, no letters had been received as of that time, which prompted the district to extend the deadline until 3 p.m. April 10.The seat became open after Director Edward Hartman resigned last week.While no reason was given for Hartman's departure, board President Gary Fedorcha said after last week's board meeting that it's believed Hartman resigned due to personal reasons.Hartman joined the board in December 2007, and most recently served as vice president, after having spent much of his tenure as board president.Whoever is chosen to fill the vacancy will serve until December.To serve beyond then, it will be necessary to run in the municipal election.Residents of the district who are interested in applying for the position of school board director may write a letter of application to Gregory S. Williams, board secretary, Northern Lehigh School District, 1201 Shadow Oaks Lane, Slatington, PA 18080.No telephone applications will be accepted. Letters can be mailed or delivered in person.Personal data, or a resume which will assist the directors in the interviews, should be included in the application.