Sen. John Breaux (D) will retire after three terms in office, he announced Monday in a Baton Rouge press conference.

Breaux’s decision ends months of speculation and dashes Democratic hopes of easily retaining the seat.

Breaux’s retirement is the fifth by a Southern Democratic Senator this cycle and sets off a competitive open-seat race to replace him.

The leading candidates to replace him are Reps. Chris John (D) and David Vitter (R). Both have been traveling the state extensively and raising money for a potential statewide race.

Vitter ended September with $1.5 million in the bank; John is expected to have more than $1 million on hand at year’s end.

“I will formally announce my intentions at a later date,” said John. “Today we should be focused on Senator Breaux and the celebration of his great career.”

Breaux joins fellow Democratic Sens. Zell Miller (Ga.), Bob Graham (Fla.), John Edwards (N.C.) and Fritz Hollings (S.C.) on the sidelines for the 2004 elections. Republican Sens. Peter Fitzgerald (Ill.) and Don Nickles (Okla.) are also not seeking re-election.