In more detail but still general. The exclusion goes like this:
Normally a domestic subsidiary qualifies for 100% exclusion (I believe it has to be affiliated which means part of the consolided tax return filing). Own over 20% - 80% exclusion. Own less than 20% - 70% exclusion.
They have changed form 20 years ago, from fuzzy memory the 70% exclusion used to be 80% (and even 90% when the top corporate rate was 48%).