Does the law of Bar Metzra apply when selling the property to a Gentile? In other words, must the seller offer the property to his Bar Metzra prior to selling it to a Gentile buyer?
No, the law of Bar Metzra does not apply towards a Gentile buyer. Accordingly, there is no need for the seller to consult with his Bar Metzra neighbor prior to selling the property to a Gentile. Nonetheless, there are other halachic issues at play when selling a property to a Gentile, which may restrict the seller from doing so.
Sources: See Michaber C.M. 175:39-40; Bava Metzia 108b; Pischeiy Choshen 11:4 and 47

Shulchan Aruch HaRav | Does the law of Bar Metzra apply when selling the property to a Gentile?

Does the law of Bar Metzra apply when selling the property to a Gentile? In other words, must the seller offer the property to his Bar Metzra prior to selling it to a Gentile buyer? No, the law of Bar Metzra does not apply towards a Gentile buyer. Accordingly, there