Trucking companies buy or lease trucks in large quantities so the get them at very low rate compared to the average person, therefore, they wouldn't lease yours for a worthwhile amount of money. I doubt a trucking company would even entertain the idea.
You may be able to lease them out to drivers, who will then go and contract to work for a company while paying you the agreed lease amount. But when things get tough they will bail and you will get screwed.
I think you are referring to a "lease operator" situation. What that means is, you contract (lease) with a trucking company to haul for them. You drive and/or hire drivers, and you take care of everything, fuel maintenance, driver wages, insurance, and the list goes on. It is difficult and the profit margin is very narrow.
My advice is to sell them and find something else to do.