The answer to your question depends on the mission of the company. Artillery units have batteries and Cavalry units have troops, both of which are basically the same as a company. Companies generally have between 70 and 200 soldiers. Combat Arms companies (such as infantry) have approximately 133 soldiers, but again, this is dependent on the type of company. Airborne units, Light Infantry units and Mechanized units differ based on their mission and method of employment.
Also, each US Infantry Division had a recon unit that was usually referred to as a Recon Troop(Mechanized). This was a small unit, smaller than a company, I believe.