Alex Hall could be leaving Orange County listings behind for luxury real estate in the Hollywood Hills … ’cause TMZ has learned she’s in talks to join “Selling Sunset” as a full-time cast member for season 10.

Sources familiar with the conversations tell TMZ … Hall, Netflix, and the series producers are actively negotiating a deal that would bring her into the flagship franchise as filming begins in Los Angeles within the next week or so.

Our sources say Hall makes a natural fit for the series … despite living in Orange County, she already works with a number of high-end L.A. clients.

The potential crossover comes as “Selling Sunset” undergoes a major cast overhaul ahead of the new season. We broke the story … Mary Bonnet, Emma Hernan, Chelsea Lazkani and Sofia Vergara‘s sister Sandra Vergara are all out for season 10 after being informed back in April their contracts would not be renewed.

We’re told Bre Tiesi and Amanza Smith are both returning for the new season … alongside original cast members Christine Quinn and Heather El Moussa.

We also broke the story … the cast of “Selling the O.C.” was recently told they won’t be filming this year, though our sources said the delay has nothing to do with Orange County drama and everything to do with “Selling Sunset” taking priority in production.