Blue Jackets general manager Scott Howson announced the deal on Tuesday night.
The 26-year-old Letestu has one assist and two penalty minutes in 11 games with the Penguins this season. He had 14 goals and 13 assists and a plus-4 rating in 64 games with Pittsburgh last season and ranked fourth among NHL rookies in game-winning goals (three), seventh in power-play goals (four) and tied for 11th place in goals.
The Alberta native was signed by Pittsburgh on March 22, 2007, after he spent one season at Western Michigan.
The groove of being behind a bench is going to be interesting at first, but thank God we have a few exhibition games to get rid of those cobwebs. Overall the excitement of it all and the freshness and coming back refreshed, all those things are going to be assets. If [the players] come ready to give their best effort in practice and games, good things are going to happen. I'm always looking for results. It's not always on the scoreboard. It's winning and building something.
— Bryan Trottier on making his return to coaching as an assistant with the Sabres