I'm not sure what EF 4 is, but in .NET, you can easily do this with SQL:
SELECT Employee.Column1, Employee.Column2, Employee.Column3, Company.Column4, Company.Column5 FROM Employee INNER JOIN Company ON Employee.CompanyID=Company.ID
Column1, Column2, Column3, Column4 & Column5 are columns that you want to show, and CompanyID from Employee, and ID from Company are related columns. I hope it helped!