Source: Chuck Greenberg approved

Chuck Greenberg has filed the paperwork and has been approved as a potential buyer for the Dallas Stars, according to a source.

Greenberg, who helped a group led by Nolan Ryan purchase the Texas Rangers last August and is no longer with the organization, is now able to explore the club's financial records and determine if he wants to put in a bid. Vancouver businessman Tom Gaglardi is still in an exclusive negotiating window and could have a signed purchase agreement at some point soon. But the process allows for others to jump in and attempt to better Gaglardi's offer.

Others, possibly Dallas Mavericks owner Mark Cuban, local oil and gas businessman Billy Quinn and Allen Americans owner Doug Miller could also get involved.

Greenberg's interest in the NHL isn't new. He helped put together the plan that allowed Mario Lemieux to purchase the Pittsburgh Penguins out of bankruptcy in the late 1990s and he tried to facilitate David McDavid's attempt to buy the Atlanta Thrashers and Atlanta Hawks, which fell through.

Richard Durrett is a columnist and reporter for ESPNDallas.com.