Personal Umbrella policy is limited to 4 rental properties

[Vinay Sakhrani]

I have my Personal Home, Auto and 6 Rental properties covered with the same insurance company. I requested a 1 million Umbrella policy to be safe but they won't include liability from rental properties under the Umbrella Policy because I own more than 4 investment properties.  I inquired with another insurance company and they also have the similar 4 property limit for Umbrella coverage.  Is this true for all insurance companies?  Ideally I want a Personal Umbrella Insurance policy that will cover my entire portfolio of rentals, personal residence and Auto.