He owns a small company.
= He has a small company.
= He runs a small company.
= He manages a small company.
= He is the owner of a small company.
= The small company is (of) his own.
以上变化形式都是可以的,仅供楼主选择,因为你没有提供相应的变化格式,所以只能多给几种选择.