Web api c # relationship between tables

I'm trying to make the relationship between two "Tables" classes.

I'm building an API for MVC5 EF6 in Visual Studio, but I need an information from one class to appear in the other.

public class ASSOCIADO
{

    public string ID_EMPRESA { get; set; }

    *public ICollection<EMPRESA> NM_FANTASIA_EMPRESA { get; set; }
    [Key]
    public string ID_ASSOCIADO { get; set; }
    public string NM_ASSOCIADO { get; set; }
    public string NR_CPF { get; set; }
    public string DS_EMAIL { get; set; }
    public DateTime? DT_NASCIMENTO { get; set; }
    public DateTime? DT_INATIVACAO { get; set; }

    *public virtual EMPRESA NM_FANSTASIA_EMPRESA { get; set; }

}

In this code above, I have the information of the associate and I have the CD_EMPRESA (KEY in the Company Class), the codes with * have been some attempts found in the internet to bring these values.

In another class I have this code:

public class EMPRESA
    {
            [Key]
            public string ID_EMPRESA { get; set; }
            public string NM_FANTASIA_EMPRESA { get; set; }

    }

I need to show NM_FANTASIA_EMPRESA in the ASSOCIATE class, so that according to the ID_EMPRESA of it.