District Attorney Geoffrey Rushlau said Wednesday he would seek a fifth term as district attorney for the Midcoast.

Rushlau has served as the chief prosecutor for Prosecutorial District 6 — consisting of Knox, Lincoln, Waldo and Sagadahoc counties — since being appointed to the post in June 1993 by Gov. John McKernan.

Rushlau, a Republican, won elections in 1994 against Kim Seaberg-Rosendo, in 1998 against Michael Turndorf, in 2002 when he was unopposed, and in 2006 against Joseph Baiungo. Rushlau is the longest serving district attorney in the region’s history. The district attorney system was created in 1978, succeeding the county attorney system.

Before becoming district attorney, Rushlau served as assistant district attorney in Sagadahoc County from 1983 to 1993 and was assistant district attorney in Androscoggin County from 1980 to 1983.

No other candidates have filed an intention to seek the post.

The deadline for party candidates to file nomination papers with the Maine Secretary of State’s Office is March 15. Unenrolled candidates, also known as independents, have until June 1 to file nomination papers. The primary election is June 8 and the general election is Nov. 2.