I hold a real estate license, only, but am somewhat familiar with both parts of your question.
Generally, and depending upon the state(s) in which you may wish to operate, a Series 7 license may be needed to "sell businesses." Series 7 licenses are regulated federally.
States regulate the exchange of real estate. The bar for entrance into real estate is rather low, and usually takes about 3 months.
There are also license reciprocity laws between certain states and others, and a (still sometimes nebulously defined) license portability, allowing real estate brokers to market "commercial" properties in other states, with or without license reciprocity in place. (States like Pennsylvania, New Jersey, Nebraska, Kentucky, and Mississippi, have very strident rules about this, and are known as "turf states." Other states are "cooperative"; others are "physical location." www.realtor.org has specifics on license portability.)
Finally, you may wish to draw the distinction between "commercial" and "investment" real estate, although all non-residential real estate is lumped under the category of "commercial real estate." With distinction, "commercial" means leasing of a space. "Investment" means buying a building with a tenant already in place and under lease, or with the hope of obtaining a tenant.
In summary, start with the state in which you reside to determine what they require of you to engage in selling businesses as well as leased properties. Again, though, selling businesses is regulated federally, and selling leased properties is regulated by the states.
Your state's Real Estate Commission will probably be the best place to begin for real estate. Searching under the general heading of Series 7 should provide a starting place for selling businesses.
May 24, 2009