Brian Kalk plans to make an announcement Wednesday about running for the seat of retiring Sen. Kent Conrad (D-N.D.), and signs indicate that the state public service commissioner will become the first GOP candidate to formally enter the open-seat race.

Kalk established an exploratory committee in January and said Monday that he will make a formal statement about a bid this week, followed by a 20-stop tour of North Dakota — a strong indication that he will officially kick off his campaign.

Conrad’s retirement has opened the door for the GOP to pick up the North Dakota Senate seat in 2012, and many Republicans have expressed interest in running. Freshman Rep. Rick Berg, state Sen. Tony Grindberg, Attorney General Wayne Stenehjem, Bismarck Mayor John Warford and state Treasurer Kelly Schmidt have all indicated that they are considering running for the seat.

No Democrats have publicly declared interest in running to succeed Conrad, but Democratic Senatorial Campaign Committee spokesman Matt Canter said the party was committed to playing in the state.

“North Dakota has a long tradition of electing strong, independent Democrats and we fully expect to have a competitive campaign there next year,” Canter said.