What happens if I only want two of a seller's three divisions?

This is workable, but how it's structured depends on how the seller's divisions are actually organized legally. If each division already operates as its own corporate entity, buying the two you want can be a straightforward share purchase of just those two entities, leaving the third with the seller entirely. If all three divisions operate inside one corporation, you're looking at either a partial asset purchase — buying the specific assets and contracts that make up the two divisions you want — or asking the seller to separate the third division out of the corporation before you buy its shares.

The nuance is untangling what the three divisions actually share. Common staff, a single lease covering all operations, shared IT systems, or contracts covering the whole business rather than one division specifically all need to be identified and divided, or the boundary you're drawing on paper won't match how the business actually runs day to day.

Because the legal structure and the operational reality don't always line up neatly, a business lawyer mapping exactly what sits where, and what's genuinely shared, is essential before agreeing to buy two of three divisions as if it were a simple line to draw.