I'd imagine there'd be competition issues with either Stagecoach or GAG if they were to look into taking over any ANE depots - though Stagecoach probably less so. 

Aside from Stagecoach and GAG, the only real contender would be Transdev. First are in an even worse position than Arriva, I don't see NatEx wanting any and below that I doubt anyone would be an improvement on the current regime. 

Honestly, I wouldn't mind Stagecoach coming into Northumberland. They know how to procure appropriate vehicles for express routes, they have a smart and professional brand and have a higher base standard than most other companies. Aside from that Transdev, with a similar approach to Blazefield, would also be interesting.