Is this an industry standard?

I am a company driver w/21 yrs in the industry (not with the same company) and am considering buying my own tractor and running under another company's authority. They want to see proof of vehicle ownership before they allow me to view the employment contract. I have a friend who runs under their authority on another account and he said he didn't view contract before he bought a vehicle. It seems a bit of a risky gamble to me. Do I not have a choice in this matter? Is this an industry standard? Any info would help. Thanks.