Sources tell WWD that Theory wants to buy the label from European private equity fund Permira, which owns a 45 percent stake in Proenza. Permira also owns Valentino Fashion Group, and was thought to be grooming Proenza designers Jack McCollough and Lazaro Hernandez to take over Valentino when Valentino Garavani retired. However, it doesn’t seem like Permira is doing a whole lot to grow the label, which could make Theory an attractive partner. Theory founder Andrew Rosen was at Proenza’s show yesterday. [WWD]