Tenancy in common is one of the ways people can co-own property. Unlike a joint tenancy, tenants in common can divide the property up into unequal shares. For example, you can get 40 percent, while three co-owners can buy 20 percent each. Any division that you all agree on is okay.
Rights of Sale
You and your fellow tenants all have the right to sell your individual ownership share. Whoever you sell to becomes a new tenant in common, with the same share and ownership rights that you formerly had. Usually, your 30, or 40 or 17.5 percent share is a share of the entire property -- it's not divided up into separate owner spaces. You and your fellow tenants can, however, divide up a property into units for each of you by drafting a written agreement.
Tenants in common often draw up an agreement on how the property will be financed and managed. The agreement can restrict the right of the co-owners to sell at will, to whoever they choose. A standard requirement is that if you want to sell, your co-owners get right of first refusal. They may also be entitled to veto possible buyers, so that they don't end up owning real estate with someone they don't trust.
You and your co-owners may no longer agree on whatever original plans you had for the property. If, say, you bought a few thousand acres together and now disagree how to use them, any one of you can propose partitioning the land in equal physical shares for each tenant. If one of you sells after partition, she sells whichever specific part of the property she now owns. If you don't want to divide the land up, the tenant who does can ask a judge to authorize it.
Partition by Sale
Partition by sale happens when it's not practical to divide the property physically. If the land is too small to divide fairly, or when you own a single building that can't be split up effectively, a judge can order you and your co-owners to sell instead. You divide profits up based on your ownership shares, less the costs of court and legal fees. This may require a settlement agreement spelling out what price is acceptable and how long to wait before you accept a lesser price.