Homegrown sports icons Mark Cuban and Dan Marino have joined a group that wants to buy the Penguins and keep them in the city to anchor a potential sports-themed development around a new arena, the group's lead backer said Tuesday. Cuban, who grew up in Mt. Lebanon and owns the National Basketball Association's Dallas Mavericks, confirmed he's joining New York financier Andrew Murstein's bid to buy the team. Cuban said by e-mail he wants "to help keep the team in Pittsburgh. That's a condition of my participation."