Kering may be the best fit among existing watch portfolio holders, but I suspect that the most likely buyer would be a company flush with cash and currently operating outside either the luxury industry or outside of the luxury watch space. Rolex, Richemont, and Swatch have plenty of steel sports watches in the $3,000-$15,000 US market where Breitling makes most of its money. IWC, Baume et Mercier, Montblanc at Richemont, Longines and Omega at Swatch, and TAG Heuer at LVMH already serve this market.
I would not be shocked to see a marauding private equity company or cash-rich Chinese firm looking to add a luxe watch brand if they see these lean times as an opportunity to "buy low."
Best,
Tim