Saks Fifth Avenue wants to buy rival Neiman Marcus. Neiman is open to a deal. But the two luxury retailers can’t agree on the terms of a marriage.

This week, Neiman rejected Saks’s most recent takeover offer, which valued the upscale chain at close to $3 billion, according to people familiar with the situation. Neiman objected to the deal’s structure, a significant portion of which wasn’t in cash, some of the people said.