The answer to your question is very simple. Any REALTOR will be able to conduct an internet database search and list all the real estate companies that are selling and have recently sold homes in your area. It's a very simple & easy task.
However, if you are looking for an agent to help you sell your home, don't rely on what listing agent has the most number of homes for sale in your area or what listing agent sold the most. You may want to consider asking a buyer's agent REALTOR for assistance. So, I invite you to visit my home sellers site for more information.
HomeSmart Real Estate