The deal announced Tuesday locks up Marty Turco's replacement through the 2012-13 season. General manager Joe Nieuwendyk (NOO'-ehn-dyk) said last month the Stars were moving on without Turco, their top goalie for nine seasons.
Dallas acquired the 26-year-old Lehtonen in February from Atlanta. He was the No. 2 pick in the 2002 draft by the Thrashers.
Lehtonen was 6-4-0 with a 2.81 goals-against average in 12 games with the Stars this season.