Umbrella company and multiple domains

[AL123al]

I'm really sorry for asking this question yet again. I have searched through previous answers but couldn't see something exactly like this I think.

There is a website called example .com. It is a sort of umbrella company for 4 other separate domains within it - 4 separate companies.

The Home page of the "umbrella" company website is example.com. It is just an image with no content except navigation on it to direct to the 4 company websites.

The other pages of website example.com are the 4 separate companies domains. So on the navigation bar there is :

Home page = example.com

company1page = company1domain.com

company2page= company2domain.com etc. etc.

Clicking "home" will take you back to example.com (which is just an image).

How bad or good is this structure for SEO? Would you recommend any changes to help them rank better? The "home" page has no authority or links, and neither do 3 out of the 4 other domains. The 4 companies websites are independent in content (although theme is the same). What's bringing them altogether is under this umbrella website -  example.com.

Thank you

[AL123al]

Thank you for your comments.

[MoosaHemani]

I agree with Peter, I have worked with a company who had several different products that are huge so they used the similar structure. I think in order to give better user experience they should have some text on home page (instead of image only) but i think from the technical SEO perspective there is no big problem with this!

[crackingmedia]

Hi Caroline

I don't think there are any fundamental issues with the structure for SEO. Many large corporates will have an "umbrella"  corporate "group" website with links to their subsidiary sites.

The critical factor for SEO as with any website and its pages is the relevancy of its content based on the many ranking factors discussed in this article: http://moz.com/search-ranking-factors

Peter