Legal Question in Real Estate Law in California

It might depend on how you hold title to the land. If you are all tenants in common, you cannot. You would need approval or file a Partition Action.

It depends on what you mean by "sell," but Mr. Selik is wrong that it matters how you hold title. You can always sell your 40% share to anyone willing to be 40% owner with the other person or people who own the other 60%, with no one's approval or any court action no matter how title is held. If, however, you mean sell the WHOLE property, then Mr. Selik is correct, you would have to have all owners agree to sell, or obtain a court order for it to be sold in a partition action.

I agree with Mr. McCormick. If you own 40%, you can sell your 40%. Doesn't matter whether you are a joint tenant or a tenant in common. Trouble is, there isn't much market for part interests in real estate. Who wants to be a co-owner with someone they don't know?

Actually, there is one infrequent exception to the above statement that a co-owner can sell his or her fractional interest. If the property was placed into a business partnership, either intentionally (by deed to the partnership) or through the conduct and actions of the owner(s) without intention, it would be necessary for the partnership to sell, since an individual partner cannot dispose of partnership property. However, co-ownership of property only occasionally gives rise to, or involves, a partnership.

As a 40% owner, you cannot sell the 60% you don't own without the other owner(s) giving you written authority.

You can sell your 40% interest to anyone, without the approval of the other person. But you cannot subdivide and sell a certain portion without complying with the Subdivison Map Act.