The deal is worth a reported $2.5 million, according to Aaron Portzline of the Columbus Dispatch.
The 28-year-old, who was set to become an unrestricted free agent this summer, is enjoying potentially his best season in the NHL. Through 34 games, he has nine goals and 20 points. His best offensive season came in 2010-11 when he had 14 goals and 27 points with the Pittsburgh Penguins in 64 games.
Letestu was acquired by the Blue Jackets for a fourth-round pick in the 2012 NHL Draft in a trade with the Penguins in November 2011.
This is a great day for me. This is something I've been thinking about for a long time. This is a great opportunity that the St. Louis Blues organization, (owner) Tom Stillman and Doug Armstrong are giving me and trusting me in doing...This is going to be a great challenge for me.
— Martin Brodeur, after announcing his retirement as an NHL player and becoming a senior adviser with the Blues on Thursday