Nylander was selected eighth overall at June's NHL draft.
"Not only does William Nylander bring a high level of speed and skill to his game but he has a very strong character on and off the ice," general manager David Nonis said in a statement. "We believe he has a very bright future and are happy to have him signed to his first NHL contract."
Nylander, 18, registered one goal, six assists, seven points and six penalty minutes in 22 games with MODO of the Swedish Hockey League in 2013-14. He also played 18 games for Rogle and 17 games for Sodertalje in Sweden's second division, posting eight points (four goals, four assists) and 19 points (11 goals, eight assists) for each club, respectively.
---Sonny Milano, the Columbus Blue Jackets' first pick in the 2014 NHL Draft, has opted to play with the Plymouth Whalers of the Ontario Hockey League.
Milano is backing out of a commitment to Boston College.
Milano also is expected to sign his entry-level contract with the Blue Jackets.
---Veteran goaltender Michael Leighton signed a one-year contract to begin a second tour of duty with the Chicago Blackhawks.
Leighton played for Chicago from 2002-04 before going from Nashville to Carolina to Philadelphia to Nashville and back to the Flyers, where he played five seasons before spending last season in the KHL.
---The NHL will move its annual Combine for draft-eligible prospects from Toronto to Buffalo in 2015 and 2016.
The event, slated for late May or early June, will be held at First Niagara Center and the HarborCenter complex that is scheduled to be completed soon. The combine will feature the top hockey talent from North America and Europe before the NHL draft is held in June.