Yes. You don't have to sell your entire entry through the Entry Marketplace.
You can list your entire eligible ownership or only a percentage of it.
You can also create multiple listings for the same entry. For example, you could create two separate listings offering 20% each.
There is no fee simply to create a listing. Your ownership remains yours until a Marketplace sale actually takes place.
You can also cancel an active listing at any time before it sells.
Important: Selling a majority share
Be especially careful when selling 51% or more of an entry.
A sale that gives the buyer 51% or more ownership transfers pick control to that buyer.